ML052060359

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Semi-Annual Groundwater Monitoring Report Third and Fourth Quarter 2004 Quarterly Sampling Events, Cover Through 6.0 Basis
ML052060359
Person / Time
Site: Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date: 03/31/2005
From: Gerard van Noordennen
Connecticut Yankee Atomic Power Co
To: Hill P
NRC/FSME, State of CT, Dept of Environmental Protection
References
CY-05-110
Download: ML052060359 (232)
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Text

Connecticut Yankee Atomic Power Company Haddam Neck Plant 362 Injun Hollow Road East Hampton, CT 06424-3099 Semi-Annual Groundwater Monitoring Report Third and Fourth Quarter 2004 Quarterly Sampling Events Prepared by Connecticut Yankee Atomic Power Company March 31, 2005 Table of Contents Section ...................................................

Page 1 Introduction

....................................................

I 1.1 Groundwater Monitoring Program Overview ....................................................

1 1.2 Groundwater Monitoring Program Plans and Procedures

...................................

2 2 Groundwater Flow and Direction

....................................................

3 2.1 Background

....................................................

3 2.2 Groundwater Elevation Data ....................................................

5 2.2.1 Third Quarter 2004 Hydrographs

..6 2.2.2 Third Quarter 2004 Groundwater Flow Maps ...........................................

8 2.2.3 Fourth Quarter 2004 Hydrographs

..9 2.2.4 Fourth Quarter 2004 Groundwater Flow Maps ..10 2.2.5 Fourth Quarter 2004 Groundwater Flow Map -Landfill Area.. 12 2.3 Seeps in the Industrial Area .12 3 Groundwater Sampling and Analysis ..14 3.1 Description of Field Measurements

.14 3.2 Summary of Field Measurements

.15 3.3 Sample Locations

.15 3.4 Routine Lab Analyses.

16 3.5 1HTD Lab Analyses and Locations

.16 3.6 Geochemical Analyses and Locations

.17 3.7 Isotopic Uranium Analyses and Locations

...............................

17 4 Laboratory Analytical Results ..18 4.1 Boron .19 4.2 Gross Alpha .20 4.3 Gross Beta .20 4.4 Tritium .21 4.5 Co-60 .21 4.6 Sr-90 .22 4.7 Cs-137 .23 4.8 Alpha Isotopic .23 4.9 Total Uranium .24 4.10 Uranium Isotopic/U-235 Enrichment

.24 4.11 Geochemical Constituents

.26 5 Data Quality Assessment

.27 5.1 Data Quality Metrics .....................

27 5.1.1 Precision

..27 5.1.2 Accuracy ..28 5.1.3 Representativeness

..29 5.1.4 Completeness

.........

29 5.1.5 Comparability

..30 5.1.6 Bias ..30 5.1.7 Laboratory Audits/Assessments/Oversight Activities

..30 5.1.8 Issue Resolution/Case Narrative

..30 5.2 Data Quality Results .31 5.2.1 Precision

..31 5.2.2 Accuracy ..33 5.2.3 Completeness

..37 Table of Contents Section ..... Page 5.2.4 Comparability

.37 5.2.5 Issue Resolution/Case Narrative

.39 5.2.6 Representativeness

.39 5.2.7 Lab Audits ...................

40 5.2.8 Analytical Bias Assessment

.40 5.3 Data Quality Summary .....................................................

47 6 Spatial and Trend Analysis ... ..................................................

49 6.1 Spatial Distribution of SOCs ......................................................

49 6.1.1 Spatial Distribution of SOCs from Third Quarter 2004 .49 6.1.2 Spatial Distribution of SOCs from Fourth Quarter 2004 .52 6.1.3 Distribution of SOCs from the Landfill Area .55 6.1.4 Distribution of SOCs from Seep Sampling .55 6.1.5 General Geochemistry Across the Site .56 6.2 Trend Analysis of SOCs .......................

58 6.2.1 Boron Trend Analysis .58 6.2.2 Gross Alpha Trend Analysis .59 6.2.3 Gross Beta Trend Analysis .59 6.2.4 Tritium Trend Analysis .60 6.2.5 Strontium-90 Trend Analysis .61 6.2.6 Cesium-137 Trend Analysis .61 6.2.7 Alpha Isotopic Analyses .62 6.3 Linear Regression Analysis ......................................................

62 6.3.1 Sr/Y-90 + Cs-137 vs Gross Beta .....................................................

62 6.3.2 Total Uranium vs Gross Alpha Regression Analysis ..............................

62 6.3.3 K+ Ion vs Gross Beta Regression Analysis ................................................

63 7 Conclusions and Recommendations

.....................................................

64 7.1 Groundwater Quality Status ......................................................

64 7.2 Contaminant Source Removal Effects .....................................................

64 7.3 Recommendations for Subsequent Sampling Events ...........................................

65 8 References

.....................................................

66 9 Definitions

.....................................................

68 10 Acronyms ..70 Il List of Tables Number..........................................................................................Page Table 2-1: Summary of Monitoring Well Information

...................................................

72 Table 2-2: Selected Events in Operation of the Water Level Monitoring System ... 74 Table 2-3: Groundwater Elevation Conditions Observed in the Perched Aquifer ... 75 Table 2-4: Groundwater Elevation Conditions Observed in the Unconfined Aquifer ... 75 Table 2-5: Groundwater Elevation Conditions Observed in the Confined Aquifer ... 76 Table 2-6: Static Water Levels in Monitoring Wells ......................................................

77 Table 3-1: Summary of Field Parameters for Third Quarter 2004 ..79 Table 3-2: Summary of Field Parameters for Fourth Quarter 2004 ..80 Table 3-3: Sample Locations and Analyses Requested (Third Quarter 2004) .. 82 Table 3-4: Sample Locations and Analyses Requested (Fourth Quarter 2004) ... 84 Table 4-1: Boron Concentrations (lig/L) in Groundwater

...............................................

87 Table 4-2: Gross a, A, Sr-90 and Cs-137 Concentrations (pCi/L) in Groundwater

... 89 Table 4-3: Tritium Concentrations (pCi/L) in Groundwater

............................

100 Table 4-4: Hard-to-Detect (HTD) Concentrations (pCi/L) in Groundwater

..................

102 Table 4-5: Total Uranium Concentrations (gg/L) in Groundwater

................................

112 Table 4-6: Isotopic Uranium Concentrations (pCiL) in Groundwater

....................

113 Table 4-7: U-2341U-238

& U-235/U Ratios in Groundwater

........................................

113 Table 4-8: Comparison of Total Uranium Concentrations

(,ig/L) in Groundwater

........ 114 Table 4-9: Major Cation and Anion Concentrations in Groundwater

.....................

115 Table 5-1: Required M DC Values .......................................................

116 Table 5-2: Field Duplicate Results (MWI 22S) for Third Quarter 2004 ...................

116 Table 5-3: Field Duplicate Results for Fourth Quarter 2004 ............................

117 Table 5-4: Lab Duplicate Results for Third Quarter 2004 .............................

118 Table 5-5: Lab Duplicate Results for Fourth Quarter 2004 ............................

119 Table 5-6: Lab Duplicate Results for Seep Sample Events ............................

120 Table 5-7: DOE QAP Lab Performance Data Summary ...............................

121 Table 5-8: MAPEP Lab Performance Data Summary ................................

121 Table 5-9: ERA Lab Performance Data Summary ...................................

121 Table 5-10: QC Summary for Third Quarter 2004 Sample Event ..................................

122 Table 5-11: QC Summary for Fourth Quarter 2004 Sample Event .......................

122 Table 5-12: QC Summary for Seep Sample Events ..................................

122 Table 5-13: Lab QC Acceptance Limits ...........................................

123 Table 5-14: Internal Performance Data Summary (LCS, MS) ..........................

123 Table 5-15: Case Narrative Summary for Third Quarter 2004 ..........................

124 Table 5-16: Case Narrative Summary for Fourth Quarter 2004 .........................

125 Table 5-17: Case Narrative Summary for Bedrock Seep Samples .......................

127 Table 5-18: Summary Statistics for Third Quarter 2004 ...............................

128 Table 5-19: Summary Statistics for Fourth Quarter 2004 ..............................

129 Table 5-20: Limiting Mean Distribution Summary for Third Quarter 2004 ................

130 Table 5-21: Limiting Mean Distribution Summary for Fourth Quarter 2004 ...............

131 Table 5-22: Observed False-Positive Rates ........................................

132 Table 5-23: Data Quality Metrics ...................................................

132 Table 6-1: Summary of Seep SOCs in the Plant Area ................................

133 iii List of Figures Number ..........................................................

Page Figure 1-1: Haddam Neck Plant Property Map ...........................................................

134 Figure 2-1: Groundwater and Surface Water Monitoring Locations at the EOF and Parking Lot Area ..........................................................

135 Figure 2-2: Groundwater and Surface Water Monitoring Locations at the Industrial Area and Upper Peninsula Area ...........................................................

136 Figure 2-3: Groundwater Monitoring Locations at the Peninsula Area .........................

137 Figure 2-4: Groundwater Monitoring Locations at the Landfill Area ..............

..............

138 Figure 2-5: Groundwater Elevation, Inferred Contours and Flow Direction in the Perched Aquifer....................................................................................................................

139 Figure 2-6: Groundwater Elevation, Inferred Contours and Flow Direction in the Unconfined Aquifer ..........................................................

140 Figure 2-7: Groundwater Elevation, Inferred Contours and Flow Direction in the Confined Aquifer ...........................................................

141 Figure 2-8: Groundwater Elevation, Inferred Contours and Flow Direction in the Perched Aquifer....................................................................................................................

142 Figure 2-9: Groundwater Elevation, Inferred Contours and Flow Direction in the Unconfined Aquifer................................................................................................

143 Figure 2-10: Groundwater Elevation, Inferred Contours and Flow Direction in the Confined Aquifer ..........................................................

144 Figure 2-11: Groundwater Elevation, Inferred Contours and Flow Direction in the Landfill Area .............................

145 Figure 2-12: Location of Seeps in the Plant Area ..................................

146 Figure 2-13: Photographs of Seeps in Contaminated Soil Removal Area ......................

147 Figure 2-14: Photographs of Seeps in Contaminated Soil Removal Area ......................

148 Figure 5-1: Mn-54 Rank Order for September 2004 ..................................................

149 Figure 5-2: Mn-54 Normality Plot for September 2004 .................................................

149 Figure 5-3: Cs-137 Rank Order for September 2004 ...................................................

150 Figure 5-4: Cs-137 Normality Plot for September 2004 ................................................

150 Figure 5-5: Co-60 Rank Order for December 2004 ...................................................

151 Figure 5-6: Co-60 Normality Plot for December 2004 ..................................................

151 Figure 5-7: H-3 Rank Order for December 2004 ..................................................

152 Figure 5-8: H-3 Normality Plot for December 2004 ..................................................

152 Figure 5-9: Fe-55 Rank Order for June 2004 ..................................................

153 Figure 5-10: Fe-55 Normality Plot for June 2004 .......................................

153 Figure 5-11: Sr-90 Rank Order for December 2004 ......................................

154 Figure 5-12: Sr-90 Normality Plot for December 2004 .....................................

154 Figure 5-13: Cm-242 Rank Order for December 2004 .....................................

155 Figure 5-14: Cm-242 Normality Plot for December 2004 ........................................

155 Figure 5-15: Am-241 Rank Order for December 2004 .......................................

156 Figure 5-16: Am-241 Normality Plot for December 2004 .......................................

156 Figure 6-1: Distribution of Selected Substances of Concerns in Monitoring Wells at the Industrial Area and Upper Peninsula Area ....................................

157 Figure 6-2: Distribution of Selected Substances of Concerns in Monitoring Wells at the EOF and Parking Lot Area ....................................

158-iv -

List of Figures Number ............................................................

Page Figure 6-3: Distribution of Selected Substances of Concerns in Monitoring Wells at the Peninsula Area ............................................................

159 Figure 6-4: Inferred Distribution of Boron (ug/L) in the Unconfined Aquifer at the Industrial Area ............................................................

160 Figure 6-5: Inferred Distribution of Boron (ug/L) in the Confined ................................

161 Figure 6-6: Inferred Distribution of Tritium (pCi/L) in the Unconfined Aquifer ...........

162 Figure 6-7: Inferred Distribution of Tritium (pCi/L) in the Confined Aquifer ...............

163 Figure 6-8: Inferred Distribution of Strontium-90 (pCi/L) in the Unconfined Aquifer. 164 Figure 6-9: Inferred Distribution of Strontium-90 (pCi/L) in the Confined Aquifer ..... 165 Figure 6-10: Distribution of Selected Substances of Concerns in Monitoring Wells at the Industrial Area and Upper Peninsula Area ........................................................

166 Figure 6-11: Distribution of Selected Substances of Concerns in Monitoring Wells at the EOF and Parking Lot Area .........................................................

167 Figure 6-12: Distribution of Selected Substances of Concerns in Monitoring Wells at the Peninsula Area ............................................................

168 Figure 6-13: Distribution of Selected Substances of Concerns at the Landfill Area ...... 169 Figure 6-14: Inferred Distribution of Boron (ug/L) in the Unconfined Aquifer .............

170 Figure 6-15: Inferred Distribution of Boron (ug/L) in the Confined Aquifer .................

171 Figure 6-16: Inferred Distribution of Tritium (pCi/L) in the Unconfined Aquifer .........

172 Figure 6-17: Inferred Distribution of Tritium (pCi/L) in the Confined Aquifer ............

173 Figure 6-18: Inferred Distribution of Strontium-90 (pCi/L) in the Unconfined Aquifer 174 Figure 6-19: Inferred Distribution of Strontium-90 (pCi/L) in the Confined Aquifer ... 175 Figure 6-20: Radar Plot of Geochemistry for Landfill Area Monitoring Wells .............

176 Figure 6-21: Radar Plot of Geochemistry for Upgradient Monitoring Wells in the Industrial Area ..... 177 Figure 6-22: Radar Plot of Geochemistry for Downgradient Monitoring Wells in the Industrial Area ............................................................

178 Figure 6-23: Radar Plot of Geochemistry for Shallow Monitoring Wells in the Industrial Area ........................................................

179 Figure 6-24: Radar Plot of Geochemistry for Deep Monitoring Wells in the Industrial Area .180 Figure 6-25: Boron Site-wide Concentration Box Plot ...................................................

181 Figure 6-26: Box Plot of Gross Alpha Concentrations in Unconfined Aquifer .............

181 Figure 6-27: Box Plot of Gross Alpha Concentrations in Confined Aquifier ................

182 Figure 6-28: Gross Alpha Site-wide Concentration Box Plot ........................................

182 Figure 6-29: Box Plot of Gross Beta Concentrations in Unconfined Aquifer ................

183 Figure 6-30: Box Plot of Gross Beta Concentrations in Confined Aquifer ....................

183 Figure 6-31: Gross Beta Site-wide Concentration Box Plot ...........................................

184 Figure 6-32: H-3 Concentration Trend at Cluster Well MW102 ....................................

184 Figure 6-33: H-3 Concentration Trend at Cluster Well MW1 03 ....................................

185 Figure 6-34: H-3 Concentration Trend at Cluster Well MWIIO ....................................

185 Figure 6-35: H-3 Concentration Trend at Cluster Well MWI105 ....................................

186 Figure 6-36: H-3 Concentration Trend at Well MWI 14S ..............................................

186 Figure 6-37: Box Plot of H-3 Concentrations in Unconfined Aquifer ...........................

187 Figure 6-38: Box Plot of H-3 Concentrations in Confined Aquifer ...............................

187 Figure 6-39: H-3 Site-wide Concentration Box Plot ......................................................

188 List of Figures Number ....................................................

Page Figure 6-40: Sr-90 Concentration Trend at Well MW105S ...........................................

188 Figure 6-41: Sr-90 Concentration Trend at Cluster Well MWI06 .................................

189 Figure 6-42: Sr-90 Concentration Trend at Cluster Well MW103 .................................

189 Figure 643: Sr-90 Concentration Trend at Well MWI04S ...........................................

190 Figure 644: Box Plot of Sr-90 Concentrations in Unconfined Aquifer ..........................

190 Figure 6-45: Box Plot of Sr-90 in Unconfined Aquifer (Expanded View) .....................

191 Figure 646: Box Plot of Sr-90 Concentrations in Confined Aquifer .............................

191 Figure 6-47: Sr-90 Site-wide Concentration Box Plot ...................................................

192 Figure 6-48: Cs-137 Concentration Trend at Cluster Well MW103 ..............................

192 Figure 6-49: Cs-137 Concentration Trend at Well MWI 15S .........................................

193 Figure 6-50: Cs-137 Concentration Trend at Cluster Well MWI02 ...............

...............

193 Figure 6-51: Box Plot of Cs-137 Concentrations in Unconfined Aquifer ......................

194 Figure 6-52: Box Plot of Cs-137 Concentrations in Confined Aquifer ..........................

194 Figure 6-53: Box Plot of Am-241 Concentrations in Unconfined Aquifer ....................

195 Figure 6-54: Box Plot of Am-241 Concentration in Confined Aquifer ..........................

195 Figure 6-55: Sr-90/Y-90

+ Cs-137 versus Gross Beta ...................................................

196 Figure 6-56: Total Uranium vs Gross Alpha .........................

..........................

196 Figure 6-57: Total Uranium vs Gross Alpha ......................

.............................

197 Figure 6-58: K-40 (K ion) versus Gross Beta ....................................................

197 Figure 6-59: Stable K versus Gross Beta..............

.............

198-vi -

List of Appendices Appendix A Appendix B Appendix C Appendix D Appendix E Appendix F Appendix G Appendix H Appendix I Procedure 5.3-1 Hydrographs and Data Quality Assessment Field Parameters Boron, Radiochemical, and General Geochemistry Laboratory Analytical Data Rank Order Plots Radar General Geochemistry Plots Boron Time Series Plots Tritium Time Series Plots Cesium-137 and Strontium-90 Time Series Plots 1 Introduction 1.1 Groundwater Monitoring Program Overview This report presents a compilation of the groundwater analytical results and related field measurements associated with two groundwater-sampling events conducted during third and fourth quarter 2004 at the Connecticut Yankee Atomic Power Company (CYAPCo) Haddam Neck Plant (HNP) located in Haddam Neck, Connecticut (Cl).These groundwater-sampling events were performed in compliance with the quarterly groundwater monitoring program Quality Assurance Project Plan (GMP QAPP 2004)and to provide characterization data input to the CY License Termination Plan (LTP 2002).The objective of this monitoring report is to provide a summary and evaluation of the groundwater analytical results and groundwater elevation data to develop an understanding of plume status concerning substances of concern (SOCs) at the HNP. A focused list of individual radioactive and non-radioactive constituents has been identified as SOCs contributing to most of the groundwater contamination at the site.The radiological SOCs at HNP have been identified as tritium, Sr-90, Cs-137, and Co-60, all predictable byproducts of the nuclear fission reaction that was the heat source for this nuclear power generating plant. Boron, the only non-radioactive SOC identified at the facility, was used as a neutron absorber in the primary cooling water, and when detected above background levels in environmental samples at HNP is used as an indication of plant-related contamination and also as an effective tracer of potentially contaminated groundwater.

Boron will be evaluated as part of the ongoing RCRA Corrective Action Program (CAP) under regulatory authority of the USEPA and in accordance with the Connecticut Property Transfer Act.In order to assess general site groundwater geochemistry and potential contaminant migration mechanism(s), supplemental analyses were collected during the third quarter 2004 event. Additionally, both SOCs and the supplemental geochemistry analyses were conducted on seeps that are located in excavated portions of the industrial area of the plant. An integral component of this data summary and evaluation is a discussion of quality-related activities performed to support validation of data collected during these two sampling events.The primary scope of the Groundwater Monitoring Program (GWMP) is to assess groundwater conditions in the industrial area, the site of former plant operations and probable source areas, and the upper peninsula area, which is adjacent to the industrial area, by conducting quarterly sampling events. These two areas comprise the area where SOCs have been historically detected and where migration pathways are likely, resulting in the greater number of wells in the monitoring network. Several wells in both the Emergency Operations Facility (EOF)/Parking Lot area, the lower peninsula area, and the landfill area are also sampled and analyzed to provide control for I monitoring groundwater conditions at the boundaries of the plant property.

Several wells installed at the HNP as part of the RCRA CAP were not included as part of the GWMP. An overview of the HNP property and the various area designations is provided in Figure 1-1.1.2 Groundwater Monitoring Program Plans and Procedures The third and fourth quarter of 2004 quarterly GWMP sampling and analysis was conducted following specific guidance under applicable CY procedures.

The framework for the GWMP is outlined as an internal CY HNP procedure that describes the methodology for implementing the required quarterly groundwater sampling and analysis (RPM 5.3-0). The GWMP Work Plan and Inspection Record (WP&IR) states specific permits, tags, and the required approval signatures needed to complete each quarterly sampling event. The Groundwater Sampling Event Planning and Data Management procedure (RPM 5.3-3) documents what should be in a Groundwater Sampling Event Plan, including data quality objectives (DQOs), sample records, analysis parameters, and equipment.

The methodology for representative sample collection and field measurements, including groundwater levels, are described in the Groundwater Level Measurement and Sample Collection in Monitoring Wells procedure (RPM 5.3-1)as attached in Appendix A.Additional sampling event-specific plans were developed for both the third and fourth quarter sampling events. A Groundwater Sampling Event Plan was developed following guidelines set forth in the Groundwater Sampling Event Planning and Data Management procedure.

All sampling and analysis was performed in accordance with the requirements of the GMP QAPP (Reference GMP QAPP 2004).2 2 Groundwater Flow and Direction 2.1 Background Groundwater elevation measurements are collected from each monitoring well sampled during the quarterly groundwater sampling events to provide a synoptic picture of hydrogeologic conditions at the facility.

These groundwater elevation data are collected to develop an understanding of groundwater flow and direction, which are essential to assessment of plume status for the primary SOCs at HNP. The groundwater elevations were measured in accordance with the Groundwater Level Measurement and Sample Collection in Monitoring Wells procedure (RPM 5.3-1).The groundwater and surface monitoring well network at HNP is shown by specific area in Figures 2-1 through 24. The EOF and parking lot area monitoring locations are shown in Figure 2-1, industrial area and upper peninsula area locations in Figure 2-2, other peninsula area locations in Figure 2-3, and the landfill area in Figure 24.The characterization of hydrogeologic conditions at HNP is ongoing, with many factors that must be considered and evaluated before an accurate depiction of groundwater flow and direction can be developed.

Site conditions such as definition and interconnection of hydrostratigraphic units, horizontal and vertical flow components, fractured flow elements, recharge/discharge zones, the impact of tidal influences, precipitation, and barometric pressure changes will be incorporated into the evaluation of hydraulic data. In addition, the mat sump hydraulic control operations, other groundwater pumping activities associated with decommissioning, and subsurface barriers to groundwater flow complicate the hydrogeologic conditions, and potentially the contaminant transport, in the industrial area. Another critical aspect concerning evaluation of groundwater flow and direction at HNP is providing an accurate datum to determine exact groundwater elevations during groundwater level gauging events.As part of the plant characterization effort, measures have been implemented to ensure valid, consistent data are collected to provide adequate quality control for the evaluation of hydraulic data and development of the hydrogeologic conceptual site model (CSM) at the facility.

A civil survey to establish horizontal and vertical position of a portion of the monitoring wells at HNP was performed by Kratzert and Jones of Middletown, Connecticut during November and December 2003 to address inconsistent well records, primarily in the industrial area. In addition to providing horizontal control for the wells surveyed, an accurate vertical datum was established for the wells surveyed to the nearest 0.01-foot, enabling adequate quality control to determine accurate groundwater elevations.

3 A network of pressure transducers were installed in selected groundwater monitoring wells and two surface water monitoring locations to collect continuous water levels and temperatures throughout HNP for an extended period of time. The pressure transducers network was installed between January 14 and January 27 2004, and the pressure transducer have been collecting elevation data since January 27,2004. The groundwater elevation data collected from this network will enable evaluation of hydrogeologic conditions and refinement of the CSM.As part of the Phase I hydrogeologic characterization effort, the hydrogeologic CSM at the HNP proposed three primary hydrostratigraphic units. Those units were defined as follows: 1) the unconsolidated deposits, 2) the shallow bedrock, and 3) the deep bedrock.The unconsolidated deposits hydrostratigraphic unit is composed of the shallow, non-lithified clastic materials at the facility, including both sedimentary deposits and man-made fill. The shallow bedrock hydrostratigraphic unit was defined as the upper ten (10) feet of the bedrock interval, immediately underlying the unconsolidated unit, and the deep bedrock unit included all bedrock below the upper 10-foot depth. Based on preliminary evaluation of hydrogeologic data, wells screened either across the unconsolidated deposits/bedrock interface or within the upper 10 feet of the bedrock displayed a hydraulic response similar to the unconsolidated deposits, rather than wells screened 10 feet or deeper within the bedrock interval.

Current understanding of the shallow bedrock hydrostratigraphic unit component of the hydrogeologic CSM suggests that in many cases it contains partially weathered rock and, therefore, may be more intensely fractured than the deeper bedrock interval, possibly exhibiting a hydraulic response more characteristic of porous media than fractured media.Additional information developed from the hydraulic response to various pumping and de-watering activities within the hydrogeologic units associated with decommissioning has further developed the understanding of the hydrogeologic CSM at the site. Based on the hydraulic response to the pumping activities, the hydrostratigraphy has been refined to include two major units that comprise an unconfined aquifer and a confined aquifer. The unconfined aquifer occurs within the unconsolidated deposits and the more fractured portions of the shallow bedrock and is defined by the water table. The portions of shallow bedrock that are included in the unconfined aquifer typically do not include a layer of till that acts to confine the bedrock. The confined aquifer comprises the deeper, more competent bedrock and typically has a layer of till capping the bedrock.A third perched aquifer is recognized in the northwestern portion of the site. In this restricted portion of the property shallow groundwater occurs within swampy deposits present in that area. This groundwater is believed to be in equilibrium with the small pond located adjacent to the perched water (Figure 2-1). A small stream discharges to the pond, and the pond water flows through a weir to a culvert on the southeast end of the pond. This perched groundwater is not believed to contribute significant recharge to the unconfined aquifer, due to the low permeability of the swampy deposits and the continuous discharge from the pond to the culvert.4 The aquifer designation for all monitoring wells included in the third and fourth quarter sampling effort is included in Table 2-1. Table 2-1 also provides well specifications for the groundwater-monitoring network, including revised horizontal coordinates and the vertical elevation of the measuring points for water level gauging for each well and screen intervals in each well.Considering the complicated site conditions previously mentioned at HNP and the preliminary status of the hydrogeologic characterization effort, the evaluation of groundwater flow velocity and direction at the industrial area and upper peninsula area is ongoing.The data from the pressure transducer network has been used to generate potentiometric maps for each of the three aquifers, which provide a framework to evaluate groundwater flow and direction at the facility.

The relationship between groundwater flow and direction at the industrial and upper peninsula areas, and the distribution of SOCs is discussed in Section 6 of this report.2.2 Groundwater Elevation Data A system of 33 data-logging pressure transducers was installed in monitoring wells at HNP and in the-Connecticut River adjacent to the plant in January 2004. This system was designed to provide a regular automated record of changes in water level elevation across the industrial portion of the site. The long-term water elevation data form the basis for meeting the following data needs:* Quantify the horizontal hydraulic gradient across the site.* Identify the apparent groundwater flow direction across the site.* Quantify the apparent vertical pressure differences between the identified aquifer units across the site.* Identify aquifer response to recharge events (e.g., rainfall events) and groundwater extraction events (e.g., mat sump operation).

  • Provide monitoring data for aquifer tests conducted as part of site characterization (e.g., aquifer pumping tests).* Quantify aquifer response to tidal fluctuations and general river stage variations in the Connecticut River.As a secondary data point, the pressure transducers also log water temperature at the same frequency as the water level.The transducer system was installed starting in the last week of January 2004. The data loggers were initially set up to record measurements on one-minute intervals and were subsequently re-programmed to record measurements on five-minute intervals in May 2004. The transducers are routinely downloaded on a quarterly basis with more 5 frequent downloads if data are required for specific needs. Significant events related to the water level monitoring system are shown in Table 2-2.The transducer system includes two data-logging barometric pressure transducers.

These units are maintained at atmospheric conditions because the submersible transducers deployed in the monitoring wells are not barometric pressure-compensated.

The electronic data are downloaded from the monitoring well data loggers and the barometric pressure transducers using a portable computer.

The data from the submerged transducers are then corrected for barometric pressure fluctuations using the data from the barometric pressure transducer(s) and proprietary software from the transducer manufacturer that calculates the corrected pressure indicated by the submerged transducers.

The resulting pressure measurements are converted to water elevations by calculating the resultant height of the water column in each well at the time of measurement and adjusting for the measured well head elevation.

The water elevations produced from the transducer data are then compared to periodic hand measurements collected using water level sounders for accuracy and precision assessment.

The detailed hydrographs for each instrumented location (i.e., the monitoring wells and the river) are included in Appendix B of this document.

The hydrographs are presented by quarter and for each monitored location, three individual hydrographs are presented; one graph of the observed water elevation only, one graph of the water level and associated temperature, and one graph of the water level compared to total daily rainfall as recorded at HNP. A data quality assessment of the hydrograph data evaluation was developed and is also included in Appendix B. The overall hydrographs are summarized and discussed in the following subsections.

2.2.1 Third Quarter 2004 Hydrographs The hydrographs for the third quarter of calendar year 2004 are discussed in the following subsections.

Connecticut River The Connecticut River exhibited strong, regular tidal fluctuation and only small variations in seasonal river stage during the period from July through August 2004.During the-third quarter 2004, the Connecticut River exhibited a steady water level elevation of approximately 0 feet MSL +/- about 2 feet of regular fluctuation due to tide.Reactor Foundation Mat Dewatering Sump The foundation mat dewatering sump, located adjacent to the reactor containment building on the plant-south side, has been in nearly-continuous operation for the life of the HNP. Evaluation of the construction drawings of the mat sump indicate that the sump is in apparent communication with the unconfined and confined aquifers at the site. A data logging pressure transducer in the sump has been recording water levels since the beginning of 2004. The mat sump is equipped with two submersible electric pumps that operate on a level control system to maintain a depressed water level in the sump. The sump pumps operate on a six-foot control level, with the pumps starting 6 when water reaches approximately elevation

-13 feet MSL, and stopping when water reaches approximately elevation

-23 feet MSL. The long-term average dynamic water level in the mat sump is approximately elevation

-20 feet MSL. Because the mat sump is under continuous active pumping, the observed water level in the mat sump does not exhibit response to local rainfall events. One shutdown of the mat sump was experienced from August 11 through 12 2004. During this event the water level recovered to a maximum elevation of -4 feet MSL.Perched Aquifer Wells screened within the underground bog deposits in and around the pond to the north-east of the industrial are considered to be in the perched aquifer. Of the four perched aquifer monitoring wells (MW505S, MW507S, MW508S and MW104), MW508S and MW104 possess data-logging pressure transducers.

Monitoring wells MW508S and MW104 consistently have groundwater elevations of approximately 10 to 13 ft MSL and do not exhibit response to dewatering activities onsite. The transducer in MW508S, however, was found to be inaccurate and the response cannot be quantified.

With the exception of MW104, water levels in monitoring wells screened in the perched aquifer do not show signs of seasonal variations.

MW104 is most likely screened across both the perched and unconfined aquifers.

It has water chemistry closely related to that of the other unconfined aquifer monitoring wells in the industrial area of the HNP (see Section 6.1), but has groundwater elevations that are more similar to the perched aquifer wells. Most likely, MW104 is on the edge of the underground bog deposits, which make it difficult to categorize definitely in one aquifer or the other. Because of this uncertainty, MW104 was utilized in the perched aquifer groundwater elevation contour maps, but contoured in the unconfined aquifer contamination plume maps. The characteristics of the wells screened in the perched aquifer are summarized in Table 2-3.Unconfined Aquifer All of the wells screened in the unconfined aquifer exhibited seasonal variations in water level. The characteristics of the wells screened in the unconfined aquifer are summarized in Table 2-4. Several of the wells were observed to exhibit drawdown in response to dewatering activities in the foundation mat sump and in specifically-installed dewatering wells in the vicinity of the plant tank farm and the primary auxiliary building.Confined Aquifer Wells that are screened within bedrock underlying the unconfined formation are considered to be in the confined aquifer. The characteristics of the wells screened in the confined aquifer are summarized in Table 2-5. The confined aquifer wells are generally not clearly and immediately responsive to local precipitation, however, most of them do exhibit pressure fluctuations that appear to be coincidental with the tidal fluctuations observed in the river.During the third quarter of 2004, several of the confined aquifer monitoring exhibited responses to the hydrophysical testing in bedrock boreholes 118A, 119 and 121A.Monitoring well MW106D responded to hydrophysical testing in borehole 118A.Monitoring well MW119 responded to hydrophysical testing in borehole 119.7 Monitoring wells MW107D, MW11OD and MW122D responded to hydrophysical testing in borehole 121A.2.2.2 Third Quarter 2004 Groundwater Flow Maps Groundwater flow maps for each of the three aquifers have been developed based on groundwater elevations measured on August 22,2004 (Table 2-6). The groundwater flow maps for each aquifer are discussed in the following sections.Perched Aquifer Groundwater elevations and flow in the perched aquifer for the third quarter sampling effort are shown in Figure 2-5. The groundwater elevations measured in the perched aquifer are representative of groundwater perched within swampy deposits that occur in the northwester portion of the Site. The perched aquifer appears to be in equilibrium with the small pond adjacent to the perched water, and most likely is recharged by the pond. Groundwater within the perched aquifer flows radially from the southeast end of the pond within the parking lot area, and may extend as far southeast as MW104S (Figure 2-5).Unconfined Aquifer The groundwater elevations measured in the unconfined aquifer are representative of the water table surface across the plant property.

Groundwater contours mapped in the unconfined aquifer are largely inferred, and generally consistent with the surface topography.

Based on the inferred contours, groundwater flow in the unconfined aquifer is generally south and southwest, towards the Connecticut River. The groundwater contours are mapped to depict discharge to the Connecticut River (Figure 2-6).Groundwater flow in the unconfined aquifer is impacted by the presence of subsurface barriers to flow. In the central portion of the industrial area several deep concrete structures are present from the ground surface to the top of bedrock. These structures include the reactor containment building (RCB), the discharge tunnel and the primary auxiliary building (PAB). As shown in Figure 2-6, the 5-foot groundwater contour is mapped much farther to the south in the western portion of the industrial area relative to the eastern portion of the site. In the central portion of the industrial area, the 5-foot contour is truncated by the discharge tunnel, is mapped around the PAB, and is continued on the north side of the RCB. The displacement of the contours is a function of the presence of the subsurface concrete structures that impede groundwater flow in the unconsolidated portion of the unconfined aquifer in the area of the RCB, discharge tunnel, and PAB.Another important feature in the industrial area is the presence of the mat sump. The sump is located adjacent to the southeast side of the RCB, and is installed approximately 40 feet below ground surface into the bedrock. The sump cycles regularly, keeping the water level in the sump between -23 and -17 feet below mean sea level (MSL). The 8 presence of the sump creates a small, but deep depression in the groundwater surface, and with the RCB acts to inhibit flow in the unconfined aquifer (Figure 2-6)Confined Aquifer Groundwater flow in the confined aquifer for the first quarter is illustrated in Figure 2-7.The bedrock monitoring wells in the northern portion of the industrial area within the confined aquifer are all influenced by the mat sump, and form a significant cone of depression in that area (Figures 2-7). Based on the large upward gradients observed in monitoring well pairs MW109D/S and MWT1OD/S, groundwater in the confined aquifer is interpreted to discharge to the Connecticut River. These monitoring well pairs are screened in the confined and unconfined aquifers, respectively adjacent to the river.The strong upward gradients are consistent with both discharge to the river, and a flow direction towards the Connecticut River for the confined aquifer.2.2.3 Fourth Quarter 2004 Hydrographs The hydrographs for the fourth quarter 2004 time period are discussed in the following subsections.

Connecticut River The Connecticut River continued to exhibit clear tidal fluctuations during the fourth quarter. The river also exhibited several cycles of rising base flow which peak on 20 September 2004 (peak river water elevation at +3.2 feet MSL), 30 September 2004 (peak river water elevation at +3.4 feet MSL), 12 December 2004 (peak river water elevation at +3.9 feet MSL), and 27 December 2004 (peak river elevation at +3.1 feet MSL). Upon retrieval of the quarterly results in December, it was determined that the on-board batteries had failed in the transducer on November 21, 2004, apparently as a result of the cold temperature to which the unit was exposed. The transducer was restored to function on December 21, 2004.An analysis of the hydrographs from the monitoring wells on site indicated that the water level in well TW-1 exhibits very close temporal and range efficiency with the river.This is consistent with the proximity of TW-1 to the river and the coarse nature of the formation in which the well is screened.

A comparative analysis revealed that the river elevation was closely approximated by subtracting 20 minutes and 0.99 feet MSL from the observed elevations of groundwater in TW-1. This value, using TW-1 as a surrogate, was used to complete the river level hydrograph for the remainder fourth quarter.Reactor Foundation Mat Dewatering Sump The mat dewatering sump continued in nearly continuous operation during the fourth quarter 2004 with average dynamic water levels at about -20 feet MSL. Three shutdowns were experienced from September 19 through September 22 2004 and again, from November 10 through November 12 and from December 23 through December 26.During these events the water level recovered to a maximum elevations between +1 and+3 feet MSL.9 Perched Aquifer Wells screened within the underground bog deposits in and around the pond are considered to be in the perched aquifer. Of the four perched aquifer monitoring wells, MW508S and MW104 possess data-logging transducers.

Monitoring wells MW508S and MW104 consistently have groundwater elevations of approximately 10 to 13 ft MSL and do not exhibit response to dewatering activities onsite. The transducer in MW508S, however, was found to be inaccurate and the response cannot be quantified.

MW104 is most likely screened across the perched and unconfined aquifers due to the fact that it has water chemistry closely related to that of the other unconfined aquifer monitoring wells in the industrial area of the HNP, but has groundwater elevations that are more similar to the perched aquifer wells. Most likely, MW104 is on the edge of the underground bog deposits, which make it difficult to categorize definitely in one aquifer or the other. Because of this uncertainty, MW104 was utilized in the perched aquifer groundwater elevation contour maps, but contoured in the unconfined aquifer contamination plume maps. The characteristics of the wells screened in the unconfined aquifer are summarized in Table 2-3.Unconfined Aquifer All of the wells screened in the unconfined aquifer exhibited seasonal variations in water level. All of the wells that were sampled as part of the quarterly groundwater monitoring event exhibited transient drawdown effects during pumping for sample collection.

The characteristics of the wells screened in the unconsolidated formation are summarized in Table 2-4. Several of the wells were observed to exhibit drawdown in response to dewatering activities in the foundation mat sump, in specifically-installed dewatering wells in the vicinity of the plant tank farm and the primary auxiliary building, and in the RHR facility pit.Confined Aquifer Wells that are screened within bedrock underlying the unconfined formation are considered to be in the confined aquifer. The characteristics of the wells screened in the confined aquifer are summarized in Table 2-5. The confined aquifer wells are generally not clearly and immediately responsive to local precipitation, however, most of them do exhibit pressure fluctuations that appear to be coincidental with the tidal fluctuations observed in the river.Monitoring wells MW1O1D, MW102D, MW103D and MW106D all exhibited a clear response to dewatering operations in the RHR facility pit. The transducer in MW1O1D, however, was found to be inaccurate and the response cannot be quantified.

As with the wells completed in the other two units, the wells that were sampled as part of the quarterly groundwater monitoring event exhibited transient drawdown effects during pumping for sample collection.

2.2.4 Fourth Quarter 2004 Groundwater Flow Maps Groundwater flow maps for each of the three aquifers have been developed based on groundwater elevations measured on December 1, 2004 (Table 2-6). The groundwater flow maps for each aquifer are discussed in the following sections.10 Perched Aquifer Groundwater elevations and flow in the perched aquifer for the fourth quarter sampling effort are shown in Figure 2-8. The groundwater elevations measured in the perched aquifer are representative of groundwater perched within swampy deposits that occur in the northwester portion of the Site. The perched aquifer appears to be in equilibrium with the small pond adjacent to the perched water, and most likely is recharged by the pond. Similar to that observed in the third quarter, groundwater within the perched aquifer flows radially from the southeast end of the pond within the parking lot area, and may extend as far southeast as MW104S (Figure 2-8). Groundwater levels in the perched water table are slightly higher in the fourth quarter relative to the third quarter levels.Unconfined Aquifer Groundwater elevations and flow in the unconfined aquifer for the fourth quarter sampling effort are shown in Figure 2-9. The groundwater elevations measured in the unconfined aquifer are representative of the water table surface in the plant property.Potentiometric contours mapped in the unconsolidated unit are largely inferred, and generally consistent with the surface topography.

Consistent with the third quarter groundwater flow maps, groundwater flow in the unconsolidated unit is generally southwest, towards the Connecticut River. Groundwater elevations across the HNP are generally higher in the fourth quarter relative to the third quarter. The groundwater contours are mapped to depict discharge to the Connecticut River.The impacts of subsurface barriers interpreted in the third quarter results are also evident in the fourth quarter water levels. The five -foot contour is displaced to the south in the western portion of the industrial area, and is mapped around the PAB and to on northern side of the RCB (Figures 2-9). The displacement of the contours is a function of the presence of the subsurface concrete structures (i.e., RCB, discharge tunnel, and PAB) that impede groundwater flow in the unconsolidated portion of the unconfined aquifer.The impact of the mat sump is also observed in the fourth quarter groundwater levels.Consistent with the third quarter groundwater levels, the presence of the sump creates a deep depression in the groundwater surface, and with the RCB acts to inhibit flow in the unconfined aquifer.Confined Aquifer Groundwater flow in the confined aquifer for the fourth quarter is illustrated in Figure2-10. Consistent with the results for the third quarter, the deep bedrock monitoring wells in the northern portion of the industrial area within the confined aquifer are all influenced by the mat sump, and form a significant cone of depression in that area (Figure 2-10).The large upward gradients observed in monitoring well pairs MW109D/S and MW11OD/S in the third quarter results are also present in the fourth quarter, consistent with both discharge to the Connecticut River, and a flow direction towards the river.11 2.2.5 Fourth Quarter 2004 Groundwater Flow Map -Landfill Area Groundwater elevations and flow in the unconfined aquifer within the landfill area for the fourth quarter sampling effort are shown in Figure 2-11. Potentiometric contours mapped in the unconfined aquifer in the landfill area are largely inferred, and generally consistent with the surface topography.

The groundwater elevations measured in the landfill area are representative of the water table surface on the plant property adjacent to the Salmon River. The groundwater flow direction in the landfill area is to the southeast towards the Salmon River and Salmon Cove (Figure 2-11). The groundwater contours are mapped to depict groundwater discharge to the Salmon River and Salmon Cove.2.3 Seeps in the Industrial Area Groundwater was observed discharging from the exposed bedrock surface as excavation of contaminated soil progressed in the service alley and PAB area. In November 2004, HNP staff collected samples of the groundwater being expressed at visible bedrock seeps in the excavation area. The samples were submitted for on-site and off-site analysis, which resulted in detection of tritium, boron, and Sr-90. No gamma-emitting radioisotopes or hard-to-detect nuclides other than Sr-90 were detected in the seep water. The seeps were sampled and analyzed for SOCs on several occasions to monitor any apparent changes in concentration of SOCs. The nature and distribution of the seeps is discussed below, and analytical results from the seep samples are discussed in Section 6.1.4.The seeps observed in the exposed bedrock appear as expressions of groundwater discharging from fractures in the rock. Bedrock in the area where seeps are observed was exposed by excavation of contaminated soil, and active dewatering has continued to maintain the bedrock surface in a dry condition.

The appearance of the seeps is a function of the local groundwater depression caused by the dewatering effort to support structure demolition and removal of contaminated soil.The elevation of plant grade is approximately 21.5 feet above mean sea level (AMSL), while historical groundwater elevation in the vicinity of the seeps was approximately 8 feet AMSL. The exposed bedrock surface in the vicinity of the observed seeps exhibits variable elevation ranging from approximately mean sea level to about 5 feet below mean sea level (BMSL). As excavation of the unconsolidated soil in the area continues, active dewatering has maintained the groundwater elevation in the unconfined aquifer in the excavation area substantially below mean sea level. As a result, groundwater from surrounding area enters the excavation area by discharging from the exposed faces of unconsolidated soil fill at the periphery of the excavation and through exposed open fractures in the exposed bedrock. Based on water level measurements in surrounding monitoring wells and the observed fracture distribution in the bedrock, the groundwater 12 discharged from the seeps is flowing into the excavation area from the general direction of the Connecticut River, which exhibits a water level generally around mean sea level.In the seep locations, this flow direction away from the Connecticut River is approximately 180 degrees different from the groundwater flow direction inferred for the area under natural hydraulic head conditions.

During the time period covered by this report (i.e., through February 2005), five seeps were identified in the excavation area (Figure 2-12). The seeps are typically observed to flow from near-vertical fractures in the exposed bedrock surface that are visible at an elevation range from about 2 feet BMSL to about 4 feet BMSL. One seep (Seep #5) was observed to be ephemeral (i.e., flow discontinued after time), while the others have been persistent.

Seeps 1, 2, 3, and 4 all exhibit estimated discharge flow rates of approximately 1 to 3 gallons per minute.Seeps 1 and 2 are located within 20 feet of the former location of monitoring well MW105S (Figure 2-2) and occur at an elevation approximately equal to the bottom of the screened interval in MW105S (note: MW105S was abandoned prior to initiating soil excavation in the area). Seep 3 is adjacent to the wall of the cable vault and Seep 4 is located near the northwest (relative to plant north) corner of the former PAB footprint.

The approximate seep locations are shown in plan view in Figure 2-12. Photographs of the seep locations are shown in Figures 2-13 and 2-14.13 3 Groundwater Sampling and Analysis This monitoring report includes the lab analytical results for two quarterly groundwater-sampling events. In addition, select analyses were performed on samples collected from groundwater seeps located within the Service Building/Primary Auxiliary Building (SB/PAB) excavation area. The third quarter (2004 Q3) sampling event occurred between September 20 and October 6, 2004. The fourth quarter (2004 Q4)sampling event occurred between December 6 and 16,2004. The groundwater seep samples were collected during the course of five (5) sample events between November 2004 and February, 2005. The results of analysis of these samples are discussed in detail in Section 4.The groundwater samples were forwarded to the GEL laboratory for radiochemical and inorganic analyses.

This report includes discussion of data validation and provides a summary of the radio-analytical results and associated quality assurance (QA) data.Some biases were observed in the radio-analytical data at low-level concentrations near the reported MDC. These positive and negative biases were observed in rank order trend plots for several nuclides.

In some cases where a positive bias was observed, these results were concluded to be false positives and part of the underlying background or baseline distribution based on the homogeneity and normality of the results. These biases are generally limited to analyses performed via liquid scintillation counting (LSC)and gas proportional counting (GPC).Measurements of field parameters were included as components of the groundwater sampling and are discussed in Section 3.1 and Section 3.2. A copy of the groundwater sampling procedure is contained within Appendix A.Groundwater samples were collected by low-flow sampling methodology utilizing either a peristaltic pump or a stainless steel submersible pump with dedicated polyethylene tubing. As a result of low water level conditions, monitoring wells MW102D and MW103D were manually purged and sampled during both sample events with a dedicated polyethylene bailer rather than using a pump.Groundwater seeps samples were collected by direct immersion into the groundwater seep with consideration for seep discharge.

Seep samples were filtered (0.45-micron filter) and preserved onsite prior to shipment offsite. A weathered rock sample was also collected in the vicinity of Seep #1. Containment Mat Sump (CMS) and Extraction Point (EP) samples were collected at the outlet of the pump following a continuous run.3.1 Description of Field Measurements Several types of field measurements were recorded in each well prior to sampling.

Data obtained from these measurements included groundwater levels, the presence or 14 absence of separate-phase fluid, and water quality parameters.

These field measurements are essential components for the evaluation of water quality and hydrogeologic conditions at the plant.Depth-to-water and bottom-of-monitoring-well sounding measurements were determined using an electronic water level meter with a 0.01 foot resolution.

Water quality parameters recorded included specific conductance, pH, dissolved oxygen, temperature, oxidation-reduction potential and turbidity.

These parameters are continuously measured prior to the sampling of each well until they have stabilized within a 10 percent variation.

This procedure is performed to confirm that well conditions have stabilized during the low-flow purging step, indicating enough water has been removed from the well so that a representative groundwater sample can be collected.

These parameters were measured using a multi-parameter meter, with sensors arrayed within a flow-through cell. The resulting measurements are included within this report as Appendix C.3.2 Summary of Field Measurements The water quality parameter field measurements for the third and fourth 2004 sampling event are summarized in Tables 3-1 and 3-2, respectively.

Field Daily Reports (FDRs), which are field notes that document the sampling of each well, are provided in Appendix C. As recorded in the field notes, the field parameters typically stabilized within an acceptable range. One of the criteria for low-flow sampling methodology employed was to collect samples where the turbidity level had stabilized in the range of 5 to 15 nephelometric turbidity units (NTUs). This range is typically used to indicate the absence of fine silt and particulate matter that may adversely affect the analytical results of the groundwater sample. In general, with few exceptions, the turbidity levels of the groundwater samples were within this range and were fairly consistent with previously collected data.As previously noted in past groundwater reports, pH continues to trend high at monitoring well MW106D and MW122D. -During the third and fourth quarter 2004 groundwater-sampling events, the pH readings from monitoring well MW106D and MW122D were reported to be in the 8.6 to 9.4 pH range. These wells have trended as high as 11.18 to 11.39 during the December 2001 sampling event. The most likely cause of the elevated pH in these wells is intrusion of cement grout into the screened intervals during well construction.

Future pH measurements from this location will be monitored and evaluated closely.3.3 Sample Locations Monitoring wells sampled during the third quarter 2004 event are located within the industrial area, parking lot, peninsula and support building areas, as indicated in Table 3-3. Monitoring wells MW114S, MW115S and dewatering well DW105 were planned but not sampled during thislsample event due to insufficient water.Several monitoring wells (MW103S, MW114S, MW115S and MW201) were planned but not sampled during the fourth quarter event due to insufficient water. Dewatering wells 15 DW1 through DW5 were planned but not sampled since the current water level was below the wells. Monitoring wells sampled during the fourth quarter 2004 sample event are located within the industrial area, parking lot, peninsula, EOF and landfill areas, as indicated in Table 34. The landfills wells were sampled during this sample event pending a decision regarding the need for additional remedial activities in the old landfill area. Samples were also collected from the Containment Mat Sump (CMS) and extraction points (EP) in the Residual Heat Removal (RHR) Pit. Two of the extraction points were located in the floor and one was located in the wall at a nominal elevation below grade. Extraction point and CMS samples were collected from the sample port or discharge hose following continuous pump operations.

Groundwater seeps samples were collected from a total of seven (7) locations in the Primary Auxiliary Buiding (PAB)/Service Building Alley excavation.

The seep samples were collected at nominally weekly intervals from November 2004 through February 2005.3.4 Routine Lab Analyses All wells sampled as part of the two quarterly sampling events were analyzed for gross alpha, gross beta and gamma isotopic analysis.

A number of industrial area monitoring wells were also sampled and analyzed for boron, tritium and Sr-90. Samples were analyzed for the following constituents and by the listed methodologies:

  • Boron via EPA method 6010B and 6020* Gross Alpha via EPA method 900* Gross Beta via EPA method 900* Tritium via EPA method 906.0* Gamma emitting fission and activation products by gamma spectroscopy
  • Sr-90 via EPA method 905.5 and gas proportional counting 3.5 HTD Lab Analyses and Locations In addition to the above analyses, samples from a subset of various locations were analyzed during each sampling event for Hard-To-Detect (HTD) plant-related radionuclides.

These HTDs include alpha, beta and X-ray emitting, fission and activation product radionuclides.

The HTD analytes and analytical methodologies included the following:

  • Iron-55 via liquid scintillation
  • Nickel-63 via liquid scintillation
  • Plutonium-241 via liquid scintillation
  • Stronium-90 via EPA method 905.5 and gas proportional counting 16
  • Tc-99 via liquid scintillation
  • Beta-emitting Pu-241 via liquid scintillation The lab analytical results are discussed in Section 4.0.3.6 Geochemical Analyses and Locations During the third quarter 2004 sampling event, samples were analyzed for the following geochemical constituents and by the listed methodologies:
  • Cations via Ion Chromatography EPA method 300.0* Anions via EPA method 300.0* Bicarbonate/Carbonate Alkalinity vie EPA method 310.1* Total Uranium via ASTM method D5174 3.7 Isotopic Uranium Analyses and Locations During the fourth quarter 2004 sampling event, a sub-set of the samples analyzed for total uranium, were selected for uranium isotopic analysis.

These samples were analyzed for the following isotopic constituents and by the listed methodologies:

  • U-235/Total Uranium ratio via inductively coupled mass spectrometry (ICP-MS)The results of analysis of the quarterly site-wide groundwater samples are discussed in Section 4.0.17 4 Laboratory Analytical Results The observed concentrations of the SOCs were compared to selected standards-in this instance, to the maximum contaminant level (MCL) promulgated under the Federal Safe Drinking Water Act regulations by the United States Environmental Protection Agency, and subsequently implemented by the State of Connecticut as the state's drinking water standards.

The MCLs do not strictly apply to groundwater at HNP because the plant groundwater is not a source of community drinking water. The MCLs do, however, provide an accepted metric for comparison and evaluation of the apparent degree of groundwater contamination.

The MCL for beta and photon emitters (such as Sr-90 and Cs-137) is a dose-based 4-mrem/year, calculated using an agency-specified target organ dose methodology.

The concentration of a single nuclide in water that would result in a dose of 4-mrem/year is often used as the MCL. This concentration is referred to as the C4 concentration, or the derived dose concentration.

If only a single beta/photon emitter is present in drinking water, the derived concentration is the MCL for that nuclide. If, however, multiple beta/photon emitters are present in the sample, the fractional dose contribution of each nuclide is summed to determine the total dose. It may be noted that by applying the NRC Total Effective Dose Equivalent (TEDE) calculation method, the yearly dose corresponding to the MCL concentrations for tritium and Sr-90 would be less than 1 mrem/yr for each nuclide.Thirty-nine (39) groundwater samples from thirty-eight (38) locations within the existing site-wide monitoring well network were collected and analyzed during the third quarter 2004, quarterly groundwater-sampling event. Boron, geochemical and radiochemical analytical results are summarized in Appendix D.1 and complete lab analytical data packages are included as Appendix D.2. Total, or unfiltered groundwater samples were collected for the boron and radiochemical constituents while geochemical analyses were performed on filtered samples. The filtered fractions were field filtered with a 0.45-pm filter.A total of fifty-eight (58) samples were collected for analysis from fifty-seven (57)monitoring wells or locations during the fourth quarter 2004 sampling event. Total or unfiltered samples were collected at all locations during this round. Boron, total uranium and radiochemical results are summarized in Appendix D.3 and complete lab analytical packages are provided in Appendix D.4.A total of thirty-five (35) samples were collected from 7 seep locations within the PAB/Service Building Alley during the November 2004 to February 2005 time frame.The samples were collected on a nominal weekly basis given groundwater seep flow considerations.

In some seep locations, as many as 6 rounds of samples were collected 18 4.1 Boron Boron is a good indicator element in groundwater at the HNP because it is chemically stable and was added to the water in the reactor vessel to control neutron flux when the plant was in operation.

Therefore, the occurrence of elevated concentrations of boron in groundwater may be a general indicator of areas that'have been impacted by previous releases.Thirty-nine (39) samples were collected and analyzed for boron as part of the third quarter 2004 round. All results were detects with reported concentrations greater than the Minimum Detection Limit (MDL) of 0.54 micrograms per liter (pg/L). Results ranged from 5.2 pg/L at MW1 to 581 pg/L at MW106S. Groundwater analytical results for the Third quarter 2004 boron analyses are summarized in Table 4-1.Boron was detected in all fifty-two (52) locations sampled and analyzed in the fourth quarter 2004 with all results above the MDL of 0.54 pg/L. The highest concentration was detected in well MW106S (802 pg/L). Groundwater analytical results for the fourth quarter 2004 boron analyses are summarized in Table 4-1.Boron was detected at all seven (7) of the groundwater seep locations at a concentration greater than the MDL. Results ranged from 117 pg/L at seep #3 to 567 Pg/L at seep #2.Groundwater seep analytical results are summarized in Appendix D.5.Boron contamination is likely present in groundwater at HNP as the orthoborate oxyanion (B0 3-3) which results directly from aqueous dissolution of boric acid (H 3 B0 3).Substantial quantities of boric acid solution were historically released from the former HNP tank farm and potentially from other locations within the industrial area. In addition to plant-related boron in groundwater, there appears to be a measurable naturally-occurring boron background concentration.

A definitive background boron study has not been performed at HNP, however, inspection of the boron analytical results suggests that a natural boron background concentration of about 50 pg/L or less is present at the site. The actual ionic species of naturally-occuring boron at HNP is not defined and may differ from the orthoborate ion. Observed boron concentrations of greater than 100 ug/L appear to be related to plant releases.

It is difficult to discern the apparent source of boron concentrations in groundwater between 50 pg/L and 100 pg/L; thus, the distal boundaries of plant-related boron plumes are not clearly defined.Boron will be evaluated as part of the ongoing RCRA CAP and Connecticut Property Transfer Act investigations.

The highest concentrations of boron observed at HNP are reported in shallow wells, with high concentrations historically found in the immediate vicinity of apparent release areas. The boron concentration in deep bedrock wells is substantially less than that in the areas of apparent contamination, although boron was detected in all but one sample collected This is consistent with the presence of a measurable boron background at the site.19 4.2 Gross Alpha The likely source of most gross alpha activity in the vicinity of HNP is dissolution of naturally occurring mineral deposits.

These mineral deposits include natural uranium, thorium and their radioactive progeny including radium (Ra-226, Ra-224), which are likely present in the underlying crystalline bedrock. Natural levels of gross alpha activity can range as high as a few hundred pCi/L. Although it is possible that plant-related radionuclides contribute to some of the observed gross alpha activity, it is not probable.

Alpha isotopic analyses for HNP related alpha-emitters (plutonium, americium, curium) generally result in non-detects with nominal detection sensitivities on the order of 0.3 pCi/L, or less.Thirty-nine (39) samples were collected and analyzed for gross alpha activity in Third quarter 2004 including the field duplicate.

Twenty-three (23) locations were detects with concentrations greater than the 2-a random uncertainty.

Fifteen (15) samples detected concentrations greater than the laboratory required Minimum Detection Concentration (MDC) of 3 picocuries per liter (pCi/L). Three (3) reported results exceeded the Environmental Protection Agency (EPA) maximum contaminant level (MCL) of 15 pCi/L. The highest gross alpha concentrations were observed at monitoring wells MW103S (17.5 pCi/L), MW508D (22.3 pCi/L) and MW507D (40.8 pCi/L). Gross alpha results for Third quarter 2004 are provided in Table 4-2.Fifty-two (52) samples were collected in fourth quarter 2004 for gross alpha activity analysis resulting in eleven (11) samples detected greater than the laboratory required Minimum Detection Concentration (MDC) of 3 picocuries per liter (pCi/L). The maximum gross alpha concentration was observed at monitoring well MW508D, 15.7 pCi/L. With the exception of MW508D, none of the other detected results exceeded the Environmental Protection Agency (EPA) maximum contaminant level (MCL) of 15 pCi/L. Gross alpha results for Fourth quarter 2004 are provided in Table 4-2.Gross alpha analyses were performed on three (3) seep samples collected during the 2nd round of seep sampling.

Gross alpha activity ranged from non-detect at Seep #3 to 7.3 pCi/L at Seep #1. Groundwater seep analytical results are summarized in Appendix D.5.4.3 Gross Beta Gross beta activity in the vicinity of HNP may result from either naturally occurring or plant-related sources. Potassium-40 (K-40) is a radionuclide resulting from naturally occurring mineral deposits, which may account for relatively high percentage of gross beta activity in certain wells. High levels of gross beta activity in areas of plant-related contamination may be associated with beta emitters Sr-90 and Cs-137. The CT Public Drinking Water Quality Standard for gross beta radioactivity is 50 pCi/L and natural background levels may range as high as a few hundred pCi/L.Thirty-nine (39) samples were collected and analyzed in third quarter 2004 for gross beta activity and all results but one (MW503) were detects with concentrations greater than the 2-o random uncertainty.

Thirty-two (32) samples detected gross beta activity at a concentration greater than the laboratory required MDC of 4 pCi/L. These 20 concentrations ranged from 4.01 (EOF2) to 47.6 pCi/L (MW103S).

None of these concentrations exceeded the CT Public Drinking Water Quality Standard MCL of 50 pCi/L. Gross beta results for Third quarter 2004 are provided in Table 4-2.Thirty-four (34) out of fifty-two (52) samples analyzed detected gross beta activity greater than the laboratory required MDC of 4 pCi/L during the fourth quarter 2004 sampling event. These concentrations ranged from 4.12 to 39.3 pCi/L. The highest gross beta activity concentration was identified in well MW106S. All results were less than the CT Public Drinking Water Quality Standard MCL of 50 pCi/L. Gross beta results for fourth quarter 2004 are provided in Table 4-2.Gross beta analyses were performed on three (3) seep samples collected during the 2nd round of seep sampling.

Gross beta activity was detected at all three (3) locations sampled with results ranging from 20.5 pCi/L at Seep #3, to 55.4 pCi/L at Seep #2.Results at Seep #2 exceed the CT Public Drinking Water Quality Standard MCL of 50 pCi/L. Groundwater seep analytical results are summarized in Appendix D.5.4.4 Tritium In the third quarter of 2004, H-3 was detected in twenty-one (21) of the thirty-eight (38)wells sampled at a concentration greater than the 2-o random uncertainty.

Fifteen (15)of these detects were at concentrations greater than the required MDC of 400 pCi/L.Tritium was detected at monitoring wells MW102S (12,600 pCi/L) and MW11OD (13,600 pCi/L). The highest tritium concentrations was observed at monitoring well MW103S (31,000 pCi/L), which is greater than the C 1 activity concentration of 20,000 pCi/L.Tritium results for the Third quarter 2004 sampling event are summarized in Table 4-3.Tritium was detected in eighteen (18) of the fifty-two (52) wells sampled during fourth quarter 2004. Sixteen (16) of these detects were at concentrations greater than the required MDC of 400 pCi/L. All detected H-3 concentrations were below the C4 activity concentration of 20,000 pCi/L. The highest tritium concentrations in monitoring wells were observed at MW102S (8,930 pCi/L) and MW103D (10,800 pCi/L). Tritium was detected at a groundwater extraction point (EP171) at a concentration of 9,040 pCi/L.Tritium results for the fourth quarter 2004 sampling event are summarized in Table 4-3.Tritium analyses were performed on seep samples collected during four (4) of the five (5) seep sampling rounds. Tritium activity was detected at all four (4) locations sampled with results ranging from 262 pCi/L at Seep #3 (round 4), to 3250 pCi/L at Seep #1 (round 2). All detected H-3 concentrations were below the C 4 activity concentration of 20,000 pCi/L. Groundwater seep analytical results are summarized in Appendix D.5.4.5 Co-60 Any occurrence of Co-60 in groundwater at HNP is the result of plant-related processes.

Cobalt-60 was detected in three (3) wells at concentrations greater than the 2-a random uncertainty level during the third quarter 2004. The concentration observed at MW106D was 2.3 pCi/L, which was less than the sample MDC of 3.8 pCi/L. Results ranged from 21 16.4 at MW508S to 44.6 pCi/L at MW102S. These results were not confirmed by reanalysis, resulting in non-detects of less than 7.9 (MW508S) and 3.3 pCi/L (MW102S).Cobalt-60 was detected in nine (9) of the fifty-two samples analyzed during the fourth quarter 2004 sample event. Only results at well MWI03D (10.2 pCi/L) were detected with a concentration greater than the sample MDC. The detected values are well below the C 4 concentration of 100 pCi/L. Table 4-4 summarizes Co-60 results in all wells that were part of the fourth quarter 2004 sampling round.Cobalt-60 was only detected in Seep #2 during the second (3.03 pCi/L) and fifth (3.08 pCi/L) sampling rounds, at concentration levels that were less than the sample MDC.The detected values are well below the Q concentration of 100 pCi/L. Groundwater seep analytical results for Co-60 are summarized in Appendix D.5.4.6 Sr-90 Strontium-90 in groundwater at HNP is also associated with past nuclear power operations.

Ten (10) out of twenty-five (25) wells sampled in Third quarter 2004 detected Sr-90 at concentrations greater than the 2-o random uncertainty.

Four (4) of these samples detected Sr-90 concentrations above the laboratory required MDC of 4 pCi/L. None of the observed Sr-90 concentrations exceeded the Q concentration of 8 pCi/L. Monitoring well MW106S exhibited the highest Sr-90 concentration (7.3 pCi/L).The Sr-90 analytical results for Third quarter 2004 are provided in Table 4-2.Ten (10) out of forty-three (43) wells sampled in fourth quarter 2004 sampling event detected Sr-90 at concentrations greater than 2-o random uncertainty, but only three (3)samples detected values above the laboratory required MDC of 4 pCi/L. Only one (1)well contained Sr-90 concentrations that exceeded the Q concentration of 8 pCi/L.Monitoring well MW106S exhibited a Sr-90 concentration of 8.6 pCi/L. The Sr-90 analytical results for Fourth quarter 2004 are provided in Table 4-2.Strontium-90 analyses were performed on seep samples collected during all five (5) seep sampling rounds. Statistically significant Sr-90 activity was detected in four (4) locations sampled. Strontium-90 results ranged from non-detects (Seep #5 and #6) to 28.6 pCi/L, at Seep #2 (round 4). Detected Sr-90 concentrations at Seep #1 through #3 were greater than the C 4 concentration of 8 pCi/L. Groundwater seep analytical results are summarized in Appendix D.5.Trend analysis of radionuclide data at these 2-a random uncertainty levels and near the sample specific MDC has indicated the presence of a positive bias in the Sr-90 analyses.Specifically, analytical results determined by liquid scintillation counting (LSC) and gas proportional counting (GPC) exhibited the most significant analytical bias. In most cases, the magnitude of the analytical bias was less than sample specific MDC.Additional trend data, to be collected during future groundwater sampling events, will determine if these reported detections at the MDC level are statistically significant, or false positive values.22 4.7 Cs-1 37 Any occurrence of Cs-137 in groundwater at HNP is the result of plant-related processes.

Cesium-137 was detected in four (4) samples analyzed during the third quarter 2004 event at concentrations greater than the 2-o TPU level. Only one sample from well MW102S out of the thirty-seven (37) samples analyzed detected Cs-137 above the laboratory required MDC of 15 pCi/L, well below the C 4 concentration of 200 pCi/L.The level of the detection in MW102S, was not confirmed by reanalysis, resulting in a detect at 2.3 pCi/L. Table 4-2 summarizes Cs-137 analytical results in all wells for the third quarter 2004 sampling round.Cesium-137 was detected in five (5) of the fifty-two (52) samples analyzed during the fourth quarter 2004 event at concentrations greater than the 2-a TPU level. All of these detections were less than the sample MDC, that ranged from 3.8 to 6.5 pCi/L and these detections were well below the C 4 concentration of 200 pCi/L. Table 4-2 summarizes Cs-137 results in all wells that were part of the fourth quarter 2004 sampling round.Gamma isotopic analyses were performed on seep samples collected during four (4) of the five (5) seep sampling rounds. Statistically significant Cs-137 activity was not detected in any of the four (4) locations sampled. All Cs-137 results were less than 6.9 pCi/L. Groundwater seep analytical results are summarized in Appendix D.5.4.8 Alpha Isotopic Alpha isotopic analyses including isotopic plutonium (Pu) and isotopic americium (Am)were determined by chemical separation and alpha spectroscopy.

Isotopic plutonium analyses include the alpha emitters, Pu-238 and Pu-239/240 and Pu-241, which is a beta emitter. Isotopic americium and curium analyses include Am-241, Cm-242 and Cm-243/244.

All of the twenty-five (25) alpha isotopic results from the third quarter 2004 sampling event were less than 2-a TPU and not statistically significant.

All alpha isotopic results were less than the required MDC of 0.5 pCi/L. Alpha isotopic results are summarized in Table 4-4.Two of the ninety-two (92) alpha isotopic results for the fourth quarter 2004 sampling event were detects with nominal sample specific MDCs or detection sensitivities on the order of 0.3 pCi/L or less. Results at MW208 for Pu-238 (0.13 +/- 0.12) were just greater than the 2-a random uncertainty.

Results at EP166 for Am-241 (0.22 +/- 0.18) were also just greater than the 2-o random uncertainty.

Table 4-4 summarizes alpha isotopic results for fourth quarter 2004. The observed positive rate for all alpha isotopic analyses was 2.2% for the fourth quarter 2004 sampling event. These sample analytical results suggest that the potential for statistically significant plant-related alpha activity in groundwater at these levels is quite small.Statistically significant activity is identified by concentrations that are greater than 2-a random uncertainty and near the MDC level. One would expect a "false positive" 23 rate of 2.5% based on the area under the standard normal distribution around a limiting mean concentration of zero at the 95% confidence level. The observed positive rate for all alpha isotopic analyses was 2.2% for the fourth quarter 2004 sampling event, which is on the order of the expected false positive rate if no significant alpha-emitters are present.Alpha isotopic analyses were performed on three (3) groundwater seep samples and one weathered rock sample collected during the 2nd round of seep sampling.

Statistically significant alpha isotopic activity was not detected in any of the four (4) locations sampled. All alpha isotopic results were less than 0.5 pCi/L. Groundwater seep analytical results are summarized in Appendix D.5.4.9 Total Uranium Total uranium analyses were determined by kinetic phosphorescence analysis (KPA).The method has trace analysis capabilities for soluble uranium on the order of parts per trillion (sensitivity of 0.2 pg/liter based on the reported MDA). Total uranium analysis would include the response from isotopes of natural and enhanced uranium which include U-234, U-235 and U-238. Total uranium analysis results would also include the response from additional uranium isotopes characteristic of irradiated or spent nuclear fuel (SNF), if present. The SNF uranium isotopes include U-233 and U-236.Twenty (20) wells were sampled and analyzed for total uranium as part of the third quarter 2004 round. Twelve (12) of these results were detects with reported concentrations greater than the Minimum Detection Limit (MDL) of 0.2 micrograms per liter (pg/L). Positive results were typically observed in the deeper wells. Total uranium concentrations ranged from 0.6 pg/L at MW122D to 27.3 pg/L at MW103S. All results were less than the EPA MCL of 30 pg/L. Total uranium analytical results for third quarter 2004 are summarized in Table 4-5.Thirty-two (32) wells were sampled and analyzed for total uranium as part of the fourth quarter 2004 round. Twenty (20) of these results were detects with reported concentrations greater than the Minimum Detection Limit (MDL) of 0.2 micrograms per liter (pg/L). Higher concentrations were typically observed in the deeper wells. Total uranium concentrations ranged from 0.003 pg/L at MW205 to 22.4 pg/L at MW1O1D.All results were less than the EPA MCL of 30 pg/L. Total uranium analytical results for fourth quarter 2004 are summarized in Table 4-5.4.10 Uranium Isotopic/U-235 Enrichment Isotopic uranium analysis was performed by chemical separation and alpha spectrometry.

Alpha spectrometry results for U-234, U-235 and U-238 in groundwater have a nominal sensitivity of 0.5 pCi/L. The U-235 enrichment ratio (U-235 to total uranium ratio) was also determined via inductively coupled plasma -mass spectrometry (ICP-MS).24 Eight (8) wells which exhibited the highest concentration of total uranium (via KPA)were analyzed for isotopic uranium by alpha spectrometry as part of the Third quarter 2004 sample event. These wells exhibited total uranium concentrations greater than, 6.8 pg/liter.

All eight (8) wells exhibited detectable U-234 results with concentrations ranging from, 1.7 pCi/L (MW100D) to 8.5 pCi/L (MW103S).

All wells also exhibited detectable U-238 results with concentrations ranging from, 2.2 pCi/L (MW1OOD), to 9.9 pCi/L (MW103S).

Uranium-235 was only detected in two (2) wells, MW1O1D (0.4 pCi/L) and MW103S (0.5 pCi/L), with a concentration greater than the 2-o random uncertainty.

All U-235 concentration results exhibited a large analytical uncertainty (i.e., 2-o random uncertainties greater than 77%). All results were less than the EPA MCL of 15 pCi/L. Isotopic uranium analytical results for the third quarter2004 are summarized in Table 4-6.Uranium-234 is a progeny of U-238 following the decay of Th-234 as follows: U-238 (a decay, T%=4.5 x 109 years)Th-234 (P- decay, Tvi=24.1 days)Pa-234 (P- decay, TiA=1.17 minutes)-U-234 (a decay, Th=2.4 x 105 years)In an ideal, closed system, a U-234/U-238 ratio of unity is expected, due to radioactive decay equilibrium.

Radioactive decay can influence this ratio somewhat in the natural environment.

The presence of the intermediate progeny (i.e., Th-234, Pa-234) with associated solubility differences and alpha recoil mechanisms are such that the actual observed ratio of U-234 to U-238 in natural groundwater can vary from 0.5 to 40. In Table 4-7 is a summary of the U-234/U-238 isotopic ratios measured by alpha spectrometry.

The U-234/U-238 ratios ranged from 0.78 to 2.1, with an average and standard deviation of 1.08 +/- 0.42. These U-234/U-238 results are typical of groundwater with natural uranium ratios.These same wells were also analyzed for U-235 enrichment (i.e, U-235 to total uranium on a mass basis) via ICP-MS. The expected U-235 enrichment ratio for uranium in groundwater or other environmental samples is less than 1% or about 0.72%(Reference GENE 1996). Uranium-235 enrichment results for these samples ranged from less than zero to 1.65% at MW100D and are included in Table 4-7. These observed enrichment results are on the order of the average ICP-MS enrichment sensitivity of 0.7%, suggesting a large analytical uncertainty on the order of 33% (relative) at 1-o, given an MDL based on 3 standard deviations of the method blank or background noise.The average and 1-a standard deviation enrichment value for these samples is 0.82% +/-0.58%. These results are normally distributed around the limiting mean enrichment value of 0.82% and are not statistically different from the expected natural enrichment value of 0.72%, based on the t-test. These results are typical of groundwater with natural U-235 enrichment ratios and relatively large analytical uncertainty.

Included in Table 4-8 is a summary of the total uranium results as measured by alpha spectrometry compared to the total uranium via KPA. The total uranium results represent the sum of the isotopic U-234, U-235 and U-238 results after conversion to 25 mass units. Isotopic results (reported as pCi/L) were divided by the nuclide specific activity constant (in units of pCi/pg) prior to summing. The uncertainty in the total uranium results (via alpha spectrometry) are based on standard uncertainty propagation methods where the isotopic random uncertainties are summed in quadrature.

The total uranium results determined by alpha spectrometry agree to within +/- 25% of the total uranium results determined by KPA. These results indicate statistical agreement of the two techniques.

4.11 Geochemical Constituents Twenty (20) filtered samples were collected from groundwater monitoring wells and analyzed for major cations and anions. The major cations analyzed included calcium (Ca+Z), magnesium (Mg~Z), sodium (Na'), and potassium (K). Major anions analyzed included carbonate (CaO 3-z), bicarbonate (HCO 3-), sulfate (S0 4-Z), and chloride (Cl-). The analytical results for major cations and anions are summarized in Table 4-9.26 5 Data Quality Assessment Current quality assurance/quality control (QA/QC) efforts in support of the Groundwater Monitoring Program at the Haddam Neck Plant (HNP) are designed to assess and enhance the reliability and validity of field and laboratory measurements conducted to support these programs.

General quality requirements are provided in References LTP 2002 and GMP-QAPP 2005.5.1 Data Quality Metrics On the analytical side, precision, accuracy, representativeness, comparability and completeness (PARCC) are the primary indicators used to assess laboratory data quality.These parameters are evaluated through laboratory QC checks (e.g., matrix spikes, laboratory blanks), replicate sampling and analysis, analysis of blind standards and blanks, and inter-laboratory comparisons.

Acceptance criteria have been established for each of these parameters.

When a parameter is outside the criteria, corrective actions are taken to minimize future occurrence.

Numerical criteria for evaluating precision, accuracy and completeness performance are generally available, while metrics for representativeness and comparability are more qualitative in nature.5.1.1 Precision Precision is a measurement of the repeatability of a measurement or measurement technique.

Precision was evaluated through the use of field duplicate samples and laboratory split or replicate samples. Field QC samples typically consist of duplicates, splits and blank samples. Field duplicate samples are used to assess sampling and measurement precision.

Field split samples are used to assess measurement precision.

Field splits and duplicates are typically examined to monitor laboratory operations and to identify potential problem areas where improvements are necessary.

27 A commonly applied and useful metric for precision is known as the Relative Percent Difference (RPD). The RPD is determined for duplicate measurements by applying the following equation: RPD = (' S 2 1 X 12 O (51 + 5 2 )/2 Where: RPD = Relative Percent Difference as %Si = Initial measurement value S 2 = Duplicate or replicate measurement value I SI -S21 Absolute measurement difference (Si + S2)/2 Average measurement value A typical acceptable target RPD is 20% for most chemical or radiological constituents in environmental media. For samples that are heterogeneous, an acceptable RPD may be as high as %100 percent.One field duplicate sample was collected during the course of each quarterly sampling event, after considerations for well yield and sample volume requirements.

Approximately 25% of the total number of samples analyzed, for radiochemical and boron constituents were internal lab duplicates or replicates.

Approximately 6% of the analyzed samples were analytical blanks.5.1.2 Accuracy Accuracy refers to the degree to which a measurement can reflect the known or true value. The accuracy of a lab analytical measurement is determined by analyzing known or reference standards or solutions.

A metric used to express accuracy in analytical measurements is the Recovery (R) which is given by the following equation: R=[1+(Y X)]xlOO Where: R = Recovery as %Y = Measured value X = Known or reference value Laboratory performance for accuracy is measured by several indicators, including external programs such as nationally based performance evaluation studies, that may include blind or double-blind standard analyses and internal laboratory QA/QC 28 programs.

Another important measure of accuracy is sensitivity.

Measurement techniques vary in their ability to detect and quantify chemical or radiochemical constituents.

For acceptable sensitivity, a measurement technique must demonstrate the capability to quantify at a level that is no more than 10% of an applicable limit (e.g., a drinking water standard).

Measurement accuracy was evaluated by three methods:* Calculation of percent recovery of laboratory control samples (e.g., calibration standards, blank spikes, and matrix spikes);* Comparison of reported minimum detectable concentration (MDC) to selected performance standards (e.g., drinking water standards);

  • Comparison of method blank analyses to the MDC.5.1.3 Representativeness Sample representativeness refers to the degree in which sample data accurately and precisely represent a characteristic of the environmental conditions at that sample point.Sample representativeness is an important PARCC parameter that is difficult to assess quantitatively.

Different measurement techniques may produce dramatically differing results, based on the ability of the technique to represent the system. This is especially true at low-levels at or near the analytical limit of detection.

One aspect of analytical representativeness was evaluated quantitatively by evaluation of method blank samples. Equipment or method blank samples that exhibited contamination (i.e., positive detects) were considered analytically non-representative.

The presence of statistically significant analyte concentrations at similar levels in measured samples may not be representative of the sampled aquifer.5.1.4 Completeness Completeness was evaluated by comparison of the number of valid measurements produced to the number of measurements planned. The Completeness (C) metric is given by the following equation: C=[ +(YAXJ]x Where: C = Completeness as %Y = Number of valid data points X = Total number of data points The target for completeness of valid measurements for all radionuclides for this sampling event was 100%. This objective was selected because critical sample locations 29 (i.e., locations that define maximum concentration and/or maximum extent of contaminant plumes) have not been established for all radionuclides or geochemical constituents.

5.1.5 Comparability Comparability was evaluated qualitatively through assessment of sampling and measurement methods and apparent spatial distribution of substances of concern.Comparability was evaluated quantitatively by comparison of the measurement sensitivity to the contract required detection limit (CRDL). Measurements performed to these levels are comparable to previous or historical measurements.

5.1.6 Bias Bias is defined as a systematic error in a measurement where the measured value displays a consistent positive or negative bias, as compared to the true value. Bias in an analytic method at low levels close to the limit of detection can impact the ability to identify statistically significant levels of an analyte. A false-positive error is an instance when a nuclide or analyte is declared to be present but is, in fact, absent. A false-negative error is an instance when an analyte is declared to be absent but is, in fact, present.Historically, commercial analytical laboratories used by CYAPCo haveexhibited some difficulty with the reporting of false-positive results, attributed to positive analytical bias at the detection limit. Statistical methods were employed to evaluate this analytical bias with regard to the underlying baseline or background distribution.

5.1.7 Laboratory Audits/Assessments/Oversight Activities Laboratory activities are periodically assessed through surveillance and/or auditing activities to ensure that quality problems are prevented and/or detected.

Periodic assessments support the continuous process improvement.

5.1.8 Issue Resolution/Case Narrative Case narrative documents record detailed documentation of the analyses requested and provide additional documentation regarding problems encountered with sample receipt, sample analysis and data reporting.

The forms are generated by the laboratory as required in the SOW and forwarded to the GW monitoring project with all hard copy data packages.

The documentation is intended to identify occurrences, deficiencies and/or issues that may potentially have an adverse effect on data integrity.

30 5.2 Data Quality Results The data quality metrics for radiochemical constituents are summarized as follows:* Precision Relative Percent Difference (RPD) < 25% or within 2-o TPU of the Initial Value* Accuracy Laboratory Control Sample Recovery 100% +/- 30 Laboratory Blank Analysis Results Non-Detect Laboratory Blank Analysis Results < MDC* Representativeness Qualitative assessment of sample location, sample timing, sample collection method, sample preservation, handling, shipment* Completeness Valid measurements for critical samples = 100%* Comparability Qualitative assessment of sample collection and measurement methods Assignment of sample locations to hydrostratigraphic units.Sample MDC < CRDL 5.2.1 Precision Results of the data quality assessment for precision are discussed in the following subsections.

5.2.1.1 Field Duplicates This field duplicate is a blind duplicate identified as MW600 on sample submission and chain-of-custody paperwork submitted to the laboratory.

The duplicate sample is typically analyzed for radioactive and inorganic constituents.

Only those reported radiocleremical results with a sufficient signal-to-noise ratio (i.e., sample-to-uncertainty concentration ratio greater than 5) are evaluated and summarized.

The uncertainty used in this ratio is the 1-o random uncertainty reported with the radiochemical results.Inorganic results that are greater than the contract required detection limit (CRDL) are also included in this evaluation.

The duplicate sample for the third quarter 2004 sampling round was collected from MWI22S. The radioactive analyses included gross alpha, gross beta, H-3, Sr-90 and gamma isotopic.

Results of the radiochemical field duplicate evaluation are summarized in Table 5-2. All radiochemical field duplicate results are within +/- 15% or 2-o standard deviations of the initial sample results.Results of the inorganic field duplicate evaluation are also summarized in Table 5-2. The inorganic analyses for third quarter 2004 included boron, cations and anions. Seven (7)of the nine (9) inorganic field duplicate results are within +/- 20% of the initial sample 31 results Field duplicate results for carbonate alkalinity were a factor of 3 lower than the initial analysis.

The initial carbonate alkalinity results are only 3 times the MDL suggesting a large uncertainty with the carbonate alkalinity at these levels (i.e., 2 to 6 mg/I). Field duplicate results for bicarbonate alkalinity were a factor of 2 greater than the initial analysis results.The duplicate sample for the fourth quarter 2004 sampling round was collected from MW102S The blind duplicate sample was analyzed for gross alpha, gross beta, H-3, boron, Sr-90, gamma isotopic and total uranium. Additional boron duplicate samples were collected at MW106S and MW125. Results of the field duplicate evaluation are summarized in Table 5-3. Again, only those radiochemical and inorganic results with a sufficient signal-to-noise ratio are evaluated and summarized.

All evaluated field duplicate results are within +/-15% of the initial sample results and indicate satisfactory precision.

Duplicate samples were not collected during the groundwater seep sampling rounds due to the data quality objectives of these samples. These samples were collected for characterization purposes only.5.2.1.2 Lab Duplicates Approximately 25% of the samples analyzed by GEL in a quarterly sampling event are internal or lab QC samples. These lab QC samples are comprised of lab control spikes, matrix spikes, method blanks, duplicates and replicates.

The reproducibility of lab measurements is evaluated through the use of matrix duplicates.

These duplicates are processed at a frequency of one matrix duplicate per batch. Internal acceptance criteria for duplicate samples are summarized as follows:* Accuracy within 20%* Accuracy within allowed uncertainty and based on contract required detection limit (CRDL)Sample and duplicate analysis results greater than 5 times the CRDL, must fall within+/- 20% of the observed value. Sample or duplicate analysis results less than the product of 5 times the CRDL, the difference should be less than or equal to the CRDL.Results of the lab duplicate evaluation for third quarter 2004 are summarized in Table 5-4. Seven (7) of twelve (12) lab duplicate results are within +/- 20% of the initial observed value. Three (3) of the remaining duplicate results are within 2 standard deviations of the initial value based on a standard Z-score indicating satisfactory statistical precision.

Results for gross beta (MW109S) and Ni-63 (MW103S) replicate analysis were outside the acceptance criteria at -30.8% and -39.9%, respectively.

All eighteen (18) geochemical lab duplicate results are within +/- 6.6% of the initial sample results.Results of the lab duplicate evaluation for fourth quarter 2004 are summarized in Table 5-5. Thirteen (13) of sixteen (16) radiochemical lab duplicate results are within 17% of the initial sample results and indicate satisfactory precision.

One gross alpha result (MW508D) and two (2) gross beta results (MW113S, MW508D) were outside acceptance 32 limits. Eleven (11) of thirteen (13) geochemical lab duplicate results are within +/- 12% of the initial sample results and indicate satisfactory precision.

Two (2) boron results (MW100D, MW100S) were outside acceptance limits at +22.3% and +31.2%, respectively.

Results of the lab duplicate evaluation for groundwater seep samples are summarized in Table 5-6. Twelve (12) of thirteen (13) radiochemical lab duplicate results are within+/- 18.5% of the initial sample results and indicate satisfactory precision.

One result for Sr-90 (Seep 1) analysis was outside the acceptance criteria at -27.1%. All eighteen (18)geochemical lab duplicate results are within +/- 7.1% of the initial sample results.5.2.1.3 Reanalysis Duplicates During the third quarter 2004 sample event, CYAPCo requested that several samples be reanalyzed to confirm the original analysis results. Reanalysis of gross alpha, gross beta, Co-60 and Cs-137 constituents were performed on sample MW102S. The original gross alpha and gross beta results were confirmed by the reanalysis.

The original levels of Co-60 (16.4 pCi/L) and Cs-137 (27.2 pCi/L) were not confirmed by the reanalysis, which indicated nion-detections.

Reanalysis of the Ni-63 fraction was also requested for MW103S. The original results were confirmed.

During the fourth quarter 2004 sample event, CYAPCo requested that several samples be reanalyzed to confirm the original analysis results. Reanalysis of the complete set of americium alpha isotopic sampes were requested due to the unexpected number and level of detections.

Nine (9) of nineteen (19) reported results for Am-241 and twelve (12)of nineteen (19) reported results for Cm-243,244 were greater than sample MDC with concentrations ranging from 0.3 to 5 pCi/L. Results of the reanalyses did not confirm the initial reported results. The analytical lab attributed these initial results to alpha particle recoil contamination effects. The original americium/curium analysis results have been flagged as rejected in the analytical database.

Results of the reanalysis indicated fifty (50) of fifty-one (51) non-detects for alpha americium.

5.2.2 Accuracy Results of the data quality assessment for accuracy are discussed in the following subsections.

5.2.2.1 External Laboratory Performance Evaluations This section provides a detailed discussion of external performance indicators for the GEL laboratories.

The GEL lab took part in US Department of Energy (DOE) Quality Assessment Program and the DOE's Mixed Analyte Performance Evaluation Program.The GEL lab also participated in the Environmental Resource Associates (ERA)RadCheMTml PT program. Results of those studies related to GW monitoring at HNP, are described in this section.DOE Quality Assessment Program DOE 's Quality Assessment Program (QAP) evaluates how laboratories perform when they analyze radionuclides in water, air filter, soil, and vegetation samples. This program is coordinated by the Environmental Measurements Laboratory (EML) in New York City, New York. EML provides blind standards that contain specific amounts of one or more radionuclides to participating laboratories.

Gamma emitters typically 33 include K40, Mn-54, Co-60, Cs-137, Bi-212, Pb-212, Bi-214 and Pb-214. Alpha emitters typically include U-234, Th-234, U-238, Pu-238, Pu-239, Am-241 and Cm-244. The beta and hard-to-detect (HTD) radionuclides typically include H-3, Fe-55, Ni-63 and Sr-90.After sample analysis, each participating laboratory forwards the results to EML for comparison with known values and with results from other laboratories.

Using a cumulative normalized distribution, acceptable performance yields results between the 15th and 85th percentiles.

Acceptable with warning results are between the 5th and 15th percentile and between the 85th and 95th percentile.

Not acceptable results include the outer 10% (less than 5th percentile or more than 95th percentile) of historical data.For the nine (9) QAP studies conducted from December 2000 through December 2004 (see References QAP-52 through QAP-60), the percentages of acceptable or acceptable with warning results are summarized as a function of media and analysis type in Table 5-6. Overall, approximately 97.1% of the GEL data was in the acceptable or acceptable with warning performance category.

For gamma isotopic analyses, 97.4% of the reported lab data was in the acceptable or acceptable with Warning category..

Approximately 98% of the alpha isotopic results and 94% of the HTD beta results were in the acceptable or acceptable with warning range. The DOE QAP60 program is the last performance that will be provided by the DOE.DOE Mixed Analyte Performance Evaluation Program DOE's Mixed Analyte Performance Evaluation Program (MAPEP) examines laboratory performance in the analysis of soil, water and particulate filter samples containing metals, volatile and semi-volatile organic compounds and radionuclides.

The program is conducted at the Radiological and Environmental Sciences Laboratory (RESL) in Idaho Falls, Idaho, and is similar in operation to DOE 's QAP discussed above. DOE evaluates the accuracy of theMAPEP results for radiological and inorganic samples by determining if they fall within a 30% bias of the reference value. Analytical results with a reported bias less than or equal to 20% are flagged as acceptable.

Analytical results with a reported bias greater than 20% but less than or equal to 30% are flagged as acceptable with warning. Analytical results for gross alpha and gross beta analyses with an analytical bias less than 100% and 50%, respectively, are acceptable.

RESL provides blind standards that contain specific amounts of one or more radionuclides to participating laboratories.

Gamma emitters typically include K-40, Mn-54, Co-57, Co-60, Zn-65, Cs-134 and Cs-137. Alpha emitters typically include U-234, U-238, Pu-238, Pu-239 and Am-241. The beta and hard-to-detect (HTD) radionuclides typically include Fe-55, Ni-63 and Sr-90. Recently, gross alpha and gross beta analysis tests for water and particulate filters have been included.The MAPEP program also uses false positive testing on a routine basis to identify laboratory results that indicate the presence of a particular radionuclide in a sample, when in fact the actual activity of the radionuclide is far below the required detection limit. False positive test nuclides typically include Sr-90, Fe-55 or Pu-238. Acceptable performance is indicated when the reported range encompassing the results (i.e., net 34 concentration

+/- 3-a uncertainty) included zero. Unacceptable performance is indicated when this range does not include zero.For the eleven (11) MAPEP studies conducted through October 2004 (see References MAPEP-S6, S7, S8, S9, S10, MAPEP-W7, W8, W9, W10, W11 and MAPEP-12), the percentages of acceptable or acceptable with warning results are summarized as a function of media in Table 5-7.Overall, about 95% of the GEL data was in the acceptable or acceptable with warning performance category for all media. For gamma isotopic analyses, 100% of the reported lab data was in the acceptable or acceptable with warning category.

Approximately 94%of the alpha isotopic results and 84% of the HTD beta results were in the acceptable or acceptable with warning range. GEL experienced some problems with the low level false positive testing where 67% of the reported results were in the acceptable range.ERA RadCheMTM Proficiency Testing (PT) Program Environmental Resource Associates (ERA) RadCheMTm PT program is based on the National Standards for Water Proficiency Testing Studies Criteria Document (Reference NSWPT 1998). ERA examines laboratory performance in the analysis of water samples containing gross alpha/beta, naturals including uranium, mixed beta and gamma emitters.

The program is conducted by ERA in Arvada, Colorado.

ERA evaluates the accuracy of submitted results for radiological samples by determining if they fall within EPA or NELAC control limits.ERA provides blind standards that contain specific amounts of one or more radionuclides to participating laboratories.

Gamma emitters typically include Co-60, Zn-65,1-131, Ba-133, Cs-134, Cs-137 and Ra-226. Alpha and beta analyses typically include gross alpha, gross beta, H-3, Sr-89, Sr-90, Ra-228 and natural uranium.The GEL lab participated in six (6) of the last seven (7) ERA studies (see References ERA RAD 52, 53,54, 55, 57 and 58). The percentages of acceptable or acceptable with warning results for these six (6) studies are summarized as a function of analysis type in Table 5-8. Overall, 98.7% of the GEL reported lab data was in the acceptable or acceptable with warning performance category for all media.5.2.2.2 Field Blank Results A decontamination station is typically established near monitoring wells sampled with non-dedicated equipment to provide for the proper decontamination of dedicated sampling equipment.

All non-disposable equipment used during the program was subject to decontamination.

These components included the groundwater sampling pump, electrical lead wires and support cable, as well as the flow-through cell in which field parameters were measured.

An equipment rinsate blank sample was not collected during the third quarter or fourth quarter of 2004 sample events since all monitoring wells were sampled using dedicated equipment.

35 5.2.2.3 Internal Lab Performance Evaluations Individual internal QC results are contained within Appendices D-1 and D-2 and indicate that the recovery rates for the laboratories are within acceptable ranges for the analyses performed.

Approximately 25% of the samples analyzed by GEL in a quarterly sampling event are QC samples. These lab QC samples are comprised of lab control spikes, matrix spikes, method blanks, duplicates and replicates.

Attached in Tables 5-9 and 5-10 is a summary of the number of QC samples processed by the GEL lab during the Third quarter and Fourth quarter 2004 sample events.Internal Performance Criteria GEL performed a minimum of one laboratory control sample (LCS), one method or reagent blank (MB), and one duplicate sample analysis for each analysis performed in a batch of samples according to References GEL QAP 2005 and CY-ISC-SOW 2003. Batch sizes are composed of one to a maximum of 20 environmental samples. Matrix spike (MS) samples are also analyzed when the analytical method involves chemical or physical separation and does not use an internal standard or carrier, and sufficient sample volume exists.Internal acceptance criteria for LCS and MS samples are summarized as follows:* Accuracy within QC acceptance limits (see Table 5-9)* Results within 2-o TPU of the observed value* Accuracy within allowed uncertainty and based on contract required detection limit (CRDL)Matrix Spikes (MS) are first corrected for any ambient test nuclide activity.

Samples with ambient activity greater than 4 times the expected value of the spike are not required to fulfill MS acceptance criteria.

The activity levels of target analytes in LCS and MS samples are greater than 10 times but less than 100 times the a priori lower limit of detection (LLD). Acceptance criteria for LCS and MS samples are 75% to 125%.Additionally, all QC and sample results must have chemical recoveries or chemical yields within the range of 15% to 125%.Internal Performance Results for Accuracy The percentages of acceptable results are summarized as a function of analysis method in Table 5-12. Overall, about 99% of the GEL performance data for LCS and MS samples were acceptable according to performance criteria.

For GPC, alpha isotopic and gamma isotopic analyses, 100% of the internal lab QC data was within acceptance limits.Approximately 98% of the LSC results and 97% of the boron, geochemical and total uranium results were within acceptable limits.Internal Performance

-Method Blank Results Method or reagent blank results are evaluated or compared to the contract required detection limit (CRDL) and the lowest sample activity in a batch. Acceptable method blanks are those results that are less than the CRDL or less than 5% of the lowest sample activity in the batch. Method blank results that do not meet the acceptance criteria are critically examined according to the GEL SOPs and documented through GEL's 36 nonconformance reporting (NCR) system. Method blank failures are also documented in the case narrative of the analytical report. Method blank activity levels are not subtracted from sample activity levels.5.2.3 Completeness Valid results were generated for a total of 544 radionuclide tests and 228 geochemical tests in the third quarter of 2004, resulting in completeness of 100%. For the fourth quarter 2004 sampling event valid results were generated for 850 radionuclide tests and 86 geochemical tests, resulting in a completeness of 100%.5.2.4 Comparability Comparability was evaluated qualitatively through assessment of sampling and measurement methods and apparent spatial distribution of substances of concern. The analytical methods used for this determination are comparable to methods used to measure dissolved species in natural waters. The sampling method and analytical techniques used in both sampling events were comparable to previous events, with the exception of the analysis of field filtered samples at some industrial area locations.

These results generally indicate that boron and radiochemical constituents detected in all wells was present in a soluble form and the filtered results are comparable to the current and previous unfiltered measurements.

5.2.4.1 Sample Methods Sample collection and control was performed using work processes and trained staff according to References RPM 5.3-0, GW-WPIR 2001 and RPM 5.3-1. The tasks included sample planning, sample collection, chain-of-custody preparation and sample shipping.The General Engineering Lab (GEL) in Charleston, SC was used as the primary lab for the radiological and boron analyses.

Methods employed for radiological constituents were standard EPA methods or were developed by the vendor laboratory and are recognized as acceptable within the radiochemical industry.

All inorganic methods are standard EPA methods. The contract required detection limits (CRDL) are identified in the laboratory Statement of Work (CY-ISC-SOW 2003) are summarized in Table 5-1.The GEL lab supplied all sample containers used in the collection of the groundwater samples that they analyzed.

Sample containers were delivered to the site by courier and maintained in a secure manner until use by the sampling team. Samples were packaged for transport to the laboratory with protective packing material in insulated coolers with custody seals.5.2.4.2 Radiochemical Data Reporting Convention All reported analytical results include the net concentration, the 1-a or 2-a random uncertainty, 1-a or 2-a total propagated uncertainty concentration (TPU), and the minimum detectable concentration (MDC). Net concentration results greater than the 2-a random uncertainty, generally imply that statistically significant activity is present with a 95% certainty.

Net concentration results less than the 2-a random uncertainty indicate zero or statistically insignificant activity.

Net concentration results reported as negative values imply that the radioactivity in the sample is less than the average or long-term background.

37 The reported TPU is a combination of the counting uncertainty and any other factors that contribute to the overall uncertainty including uncertainties in the sample mass, chemical yield and determination of calibration factors. Uncertainty values reported at 2-a allow direct comparison with the net concentration for statistical significance.

Uncertainty values reported at 1-o are converted to 2-o for comparison purposes.Detection limits are essential for evaluating data quality and demonstrating that the desired sample analytical sensitivity was achieved.

The lower limit of detection (LLD) is the lower limit at which a measurement can be differentiated from background with some degree of confidence.

The LLD for a radionuclide is typically computed from the counting error associated with the instrument background, or blank counting conditions, at the time of analysis and is usually expressed in terms of counts, or count rate. In contrast, the MDC includes conversion factors to relate background count rate to radionuclide activity or concentration.

The contractual (or a prion) MDCs for these results identified in the laboratory Statement of Work (CY-ISC-SOW 2003) are summarized in Table 5-1. These contract required detection limits (CRDL) are based on the resident farmer scenario with a 1 millirem per year Total Effective Dose Equivalent (TEDE) annual dose. All reported MDC concentrations are a posteriori afid include sample specific corrections for radioactive decay, chemical yield and sample mass.5.2.4.3 Radiochemical Data Review All analytical results in the form of the sample specific MDC were evaluated against the contractual MDCs to ensure that sensitivity requirements were met. The sensitivity requirement is relaxed when statistically significant activity is identified in order to conserve lab cost and instrument resources.

Several instances were identified in the case narrative where required sensitivities were not achieved (i.e., the sample specific MDCs were greater than the CRDL). In some cases this is attributed to a small sample mass or a low chemical recovery resulting in a low recovered sample mass. Ideally, these samples are reanalyzed with a larger sample volume, when available.

In all cases, the CRDL for Am-241 0.5 pCi/liter was not achieved when analyzed by gamma spectrometry, but it was easily achieved by alpha spectrometry.

Results that were statistically significant were tracked and trended with previous results. Results greater than the MCL or the CRDL require continued sampling.Simple rules of thumb were used to evaluate analytical results that were not statistically significant with respect to background.

Based on the theoretical relationship of the 1-o net concentration uncertainty and the 1-o background concentration uncertainty (which is the basis for the MDC), the MDC-to-uncertainty ratio was evaluated.

numerically for consistency and reasonableness.

In this case, the 2-o TPU uncertainty was used as the estimator for the 1-a net concentration in the evaluation and MDC-to-uncertainty ratios less than 1.5 were flagged for additional review. These thumb rules do not apply to low count rate results typical of alpha isotopic analyses where MDC-to-TPU ratios can span the range from 1 to 25.-38 5.2.5 Issue Resolution/Case Narrative Case narrative documents record detailed documentation of the analyses requested and provide additional documentation regarding problems encountered with sample receipt, sample analysis and data reporting.

The forms are generated by the laboratory as required in the SOW and forwarded to the GW monitoring project with all hard copy data packages.

The documentation is intended to identify occurrences, deficiencies and/or issues that may potentially have an adverse effect on data integrity.

These case narratives are included in Appendixes D with the laboratory analytical data sheets.Specific quality issues identified by the GEL lab during the reporting of third quarter and fourth quarter 2004 sampling event data are summarized in Tables 5.15 and 5.16, respectively.

Specific issues identified by the GEL lab during the reporting of Seep sampling event data included in Table 5.17. In some cases, these occurrences initiated internal non-conformance action on the part of GEL Charleston lab with additional follow-up documentation.

We will continue to monitor these case narratives and their impact on lab data quality.5.2.6 Representativeness Representativeness of sample analyses was evaluated qualitatively.

Samples collected during the Third and Fourth quarter sampling events exhibited variability in turbidity.

The cause of this variability is not apparent, but probably results from accumulation of fine geologic material in the wells due to variations in degree of well development as well as variations in the content of fine material at the various locations sampled.Redevelopment of existing monitoring wells has been performed on a limited number of wells in an attempt to provide samples with more uniform turbidity across the site.Comparison of observed turbidity measurements to analysis of radiochemical constituents in both filtered and unfiltered samples indicates no apparent correlation.

Essentially all observed radiochemical constituents appear to be present in a soluble state. Therefore it is concluded that variations in sample turbidity did not affect radiochemical analyses.Boron is expected to be present in groundwater as a soluble oxyanion and, therefore, the measured concentrations are not expected to be affected by variations in sample turbidity.

The low-flow sampling method is expected to produce representative samples for boron analysis.Monitoring wells have been assigned to unique hydrostratigraphic units based on the relative placement of screen intervals in each of the wells. The wells retain the designation of shallow or deep as these generally differentiate whether the screens are placed in unconsolidated sediments or bedrock. Three distinct hydrostratigraphic units are recognized, 1) the unconsolidated sediments are those non-indurated, friable materials overlying the bedrock, and are the host to the unconfined aquifer, 2) the bedrock unit which is the host to the confined aquifer and generally recognized as a gneissic formation, 3) a silt and peat/organic rich layer has been designated as a perching horizon in the area of the parking lot extending to the north where the perched water table occupies an elevation of about 10 feet AMSL. A glacial till is present locally 39

---over a small part of the land area, and where present typically acts as a confining layer.The assignment of wells to specific units affects the spatial distribution interpretation for the substances of concern.Samples collected from wells MW106D and MW122D exhibited elevated pH relative to other wells at the site. The cause of the elevated pH is not apparent and could result from either natural processes (e.g., encountering localized carbonate-rich rock) or from man-made processes.

Review of well logs indicates that these wells were constructed using 2-inch diameter casing inside 3-inch boreholes.

The elevated pH may result from intrusion of cement grout into the screened interval during well construction in these inadequately-sized boreholes.

These two wells also exhibit higher dissolved carbonate concentrations than other deep wells.5.2.7 Lab Audits No onsite audits or assessments were conducted at the GEL facility during this time period.5.2.8 Analytical Bias Assessment Historically, commercial analytical laboratories used by CYAPCo have exhibited some difficulty with the reporting of false-positive results, based on MAPEP performance evaluation (PE) data and trend analysis of analytical sample results. These difficulties were generally limited to radioisotopes analyzed via liquid scintillation counting (LSC)and to a lesser extent, gas proportional counting (GPC).Positive trends and biases have been observed in the past with the following nuclides analyzed via LSC at levels near the reported MDC: Fe-55, Ni-63, Tc-99 and Pu-241. Low-level analytical positive trends have also been observed for Sr-90, gross alpha and gross beta analyses, which are analyzed via gas proportional counting (GPC). Significant trends with gamma or alpha isotopic analysis results are less common.A positive bias was observed for H-3 results analyzed via LSC during the third quarter sample event. The magnitude of the positive bias was less than the analysis sensitivity or average MDC. Positive bias was also observed in the gross beta and Sr-90 results analyzed by GPC methods. No bias was observed for gamma isotopic analysis methods.Negative biases were not observed during the third quarter 2004 round.A positive bias was observed for H-3 analyzed via LSC during the fourth quarter sample event. The magnitude of the positive bias was less than the analysis sensitivity or average MDC. Positive bias was also observed in the gross beta and Sr-90 results analyzed by GPC methods. Negative biases were not observed during the Fourth quarter 2004 round.Statistical and visual methods were employed to evaluate trends in the analytical results as a function of nuclide. Rank order plots for the third and fourth quarter 2004 sample 40 events were prepared as a function of nuclide (see Appendix E). The analytical data were treated as follows:* Net concentration results at all well locations were arranged in ascending order* Standard distributional statistics were calculated (i.e., mean, median, minimum, maximum and standard deviation for the net concentration, 2-a random uncertainty and MDC)* Net concentration results with associated random uncertainty error bars were graphed as a function of rank order* Expected zero mean concentration and 2-a zero mean concentration control limits graphed as a function of rank order* Average MDC graphed as a function of rank order Graphing the expected zero mean and associated 2-a zero mean concentration control limits provides a visual indication of biases in the analytical technique at concentration levels near or below the MDC. The expected +/- 2-a zero mean control limits were based on actual sample data when activity was near or less than the MDC. In most cases, the average 2-o TPU provides restrictive control limits that are more sensitive than the standard deviation of the mean concentration, which is subject to the influence from positive outliers.

For analyses that were generally statistically significant with respect to background (i.e., gross alpha, gross beta), analytical blank data were used to estimate the 2-a zero mean control limits.Statistical methods were used in order to accurately identify and quantify biases in analytical lab data. Some basis statistical parameters for the third and fourth quarter 2004 events are summarized in Tables 5-15 and 5-16, respectively.

These methods included segregation of the analytical data into logical subsets, use of outlier detection methodology, and identification of statistical significant bias. Logical data subsets were typically comprised of an individual nuclide by sample event or sample analysis batch.For LSC analysis, a logical subset may consist of samples counted in a single batch. Due to the number of samples collected, multiple batches may be processed for each analyte in a typical sampling event.A typical groundwater analysis data subset (i.e., by nuclide) was assumed to be comprised of two distributions, an underlying background or zero analyte component randomly distributed around zero, and an unknown spatially or temporal varying distribution characterized by statistically significant or higher analyte concentrations.

In most circumstances, the limiting mean value of the underlying blank is expected to be a constant with random fluctuations normally distributed around zero, after correcting for instrument background or blank conditions.

In the case of a systematic bias in the blank, the limiting mean value of the blank distribution will be normal and randomly dlictfrihitPc1 rnrmindl n n~nn7PrA {i P ,ACitUvP Ar n PfjntiVP vnllPb WAhcrn thn ,-Thtn nr Given the rank order of the data set, a modified Z-score method was used starting on the low analyte concentration end, to identify statistical outliers on the high analyte concentration end of the data set. The Z-score test is a standard statistical method to identify outlier data. Positive outliers as identified were assumed to be nonzero or part of the spatially or temporally distributed data. All others results were considered to be part of the zero analyte or baseline distribution.

The limiting mean and standard deviation of these baseline mean results were used as an indicator for technique bias at concentrations near the MDC.The underlying background or baseline data were evaluated for normality based on Filliben's r-statistic, also known as the normal probability plot correlation coefficient.

Filliben's r-statistics near unity are characteristic of normally distributed data. Results of the normality testing for the third and fourth quarter 2004 sample events are summarized in Tables 5-17 and 5-18, respectively.

Standard hypothesis testing was also used to determine if the limiting mean bias was statistically different from zero. The limiting mean baseline results were evaluated for statistical significance using the Student's t-test. In order to concentrate our efforts on analyses with the most significant bias, we used a 3-c; criterion to identify with a high degree of confidence (i.e., at the 99.97% confidence level) analyses with significant bias with respect to the underlying background or baseline.

Our selection of a 3-a criterion in this case is based on conventional control chart theory where the analytical technique is said to be in control (i.e., no apparent bias) when the observed limiting mean value is within +/- 3-a of the expected zero analyte concentration.

Results of t-testing for the third and fourth quarter 2004 sample events are also included in Tables 5-17 and 5-18, respectively.

Some typical examples of the application of these statistical based methods as a function of general analysis type or nuclide-of-interest are as follows.5.2.8.1 Gamma Emitters Manganese-54 is a gamma emitter, determined by photon counting or gamma isotopic analysis.

Manganese-54 is produced by neutron reactions with structural stainless steel and has an expected low radionuclide inventory due to a short radioactive half-life of 312.7 days. It has decayed through greater than 7 half-lives since plant shutdown and less than 0.5% of its shutdown activity or inventory remains. Mn-54 is not expected to be present in detectable quantities in groundwater samples from the HNP and is a good candidate analysis to demonstrate a zero analyte or underlying background distribution.

Figure 5-1 is a rank order plot of Mn-54 concentrations in groundwater for the third quarter 2004 sampling event. The Mn-54 results are graphed with their corresponding 2-a error bars. An average and 1-o standard deviation concentration of -0.32 +/- 0.99 pCi/L was observed in this data set while the average MDC was 3.8 pCi/L. The control limits are +/- 1.98 pCi/L based on the 2-ca standard deviation of the limiting mean.Approximately half the data points are distributed above or below the zero concentration level. Note that the 2-a error bars generally cross zero except in the extreme positive or negative regions of the data.The limiting mean value of -0.32 pCi/L is statistically equal to a zero concentration level based on the t-statistic and 41 (n-1) degrees of freedom. The data are also normally 42 distributed around the limiting mean value as illustrated by the frequency distribution in Figure 5-2. As expected, no significant Mn-54 activity is indicated in this trend plot and the data are equally distributed around zero. These results are typical of gamma isotopic analysis where no analyte is present and the background or energy baseline is easily and'accurately determined.

Cesium-137 is a gamma emitter, determined by photon counting or gamma isotopic analysis.

Cesium-137 is a fission product with a 30.17-year radioactive half-life.

Due to a high radionuclide inventory and radioactive half-life, or decay considerations, Cs-137 has been detected in groundwater samples from the HNP.Figure 5-3 is a rank order plot of Cs-137 concentrations from the third quarter 2004 sampling event. Only results with concentrations less than 10 pCi/L, are displayed in order to focus attention on the underlying baseline distribution.

An average and 1-o standard deviation concentration of 0.55 +/- 1.15 pCi/L, was observed for the limiting zero mean while the average MDC was 3.91 pCi/L. The control limits are +/- 2.30 pCi/L based on 2-a standard deviations of the limiting mean. Results with concentrations greater than, 2.8 pCi/L were determined to be statistically different from the underlying background based on outlier testing. The baseline data are normally distributed around the limiting mean value of 0.55 pCi/L in Figure 5-4 and the limiting mean value is not statistically different from zero, based on the t-test. These results are again typical of gamma isotopic analysis with zero analyte data.Cobalt-60 is a gamma emitter with a high radionuclide inventory at HNP due to its presence in structural material.

Cobalt-60 has a radioactive half-life of 5.271-years and about 42% of its shutdown inventory or activity remains. Cobalt is a common impurity in stainless steel and is the dominant external dose producing isotope in reactor interior components on a 10-year time scale.Figure 5-5 is a rank order plot of Co-60 concentrations in groundwater for the Fourth quarter 2004 sampling event. An average and 1-a standard deviation concentration of 0.40 +/- 1.35 pCi/L was observed for the limiting zero mean while the average MDC was 5.6 pCi/L. The control limits are +/- 2.70 pCi/L based on 2-a standard deviations.

The baseline data are normally distributed around the limiting mean value of 0.40 pCi/L (Figure 5-6). The limiting mean is statistical greater than zero based on the t-test. There were seven (7) positive outliers in this Co-60 data set.It is important to note that Co-60 is also a common trace contaminant in materials used in the construction of high-purity germanium (HPGe) detectors.

These HPGe detectors are used for the gamma isotopic analyses.

It is not uncommon to observe Co-60 peak background response rates on the order of 0.001 count per second, depending on the HPGe detector size and configuration.

Given the sensitivity requirements for these analyses, the ability to accurately distinguish low-level Co-60 (i.e., pCi/L amounts) in groundwater from the detector background contribution is non-trivial.

These results are typical of gamma isotopic analysis where the underlying baseline distribution is homogenous and normally distributed, and the presence of statistically significant Co-60 43 is indicated near the MDC. In the past, we have observed positive biases for Co-60, on the order of 0.4 pCi/L.5.2.8.2 Beta and X-Ray Emitters via LSC Figure 5-7 is a rank order plot of H-3 concentrations in groundwater for the fourth quarter 2004 sampling event. Tritium is a beta emitter, determined by distillation and LSC. An average and 1-a standard deviation concentration of 51.5 +/- 83.6 pCi/L was observed in'this data set while the average MDC was 327 pCi/L. The control limits are+/- 167.2 pCi/L based on the average 2-a standard deviation.

Note that thirty-one (31) of the forty-one (41) data points are distributed above the zero concentration level.The limiting mean value of 51.5, pCi/L is statistically greater than the zero concentration level based on the t-statistic and 40 (n-1) degrees of freedom. The data are also normally distributed around the limiting mean value as illustrated by the frequency distribution in Figure 5-8. A significant positive bias is indicated in this trend plot and the data are equally distributed around the limiting mean. These results are typical of LSC analysis where a significant positive systematic bias in the underlying baseline distribution exists. In the case of tritium, this underlying baseline may be attributed to natural background levels of tritium, which are expected to be on the order of 20 to 100, pCi/L.Figure 5-9 is a rank order plot of Fe-55 in water for the June 2004 sampling event.Iron-55, which decays by electron capture and subsequent X-ray emission, is determined by LSC analysis.

Iron-55 has a radioactive half-life of 2.7-years and only 19% of its shutdown inventory or activity remains. An average and 1-a standard deviation concentration of -22.8 +/- 4.1 pCi/L was observed in this sample event data set with an average MDC of 11.7 pCi/L. The Fe-55 data are normally distributed around the limiting mean value of -22.8 pCi/L as indicated in Figure 5-10. The limiting mean value is statistically less than zero, based on the t-test. These results are typical of LSC analysis where a significant negative systematic bias in the underlying baseline distribution exists. In the past, we have observed both positive and negative biases with Fe-55 analytical results. This suggests that the analytical laboratory has some difficulty in determining the appropriate analytical blank contribution for Fe-55.Similar results were obtained for other LSC radionuclides.

CYAPCo will continue to statistically evaluate and monitor these data. In the meantime, we will report the data as is in order to evaluate any dose risk associated with groundwater monitoring in a conservative manner.5.2.8.3 Beta and Alpha Emitters via GPC Figure 5-11 is a rank order plot of Sr-90 in water for the fourth quarter 2004 sampling event. An average and 1-a standard deviation concentration of 0.14 +/- 0.22 pCi/L was observed in the limiting mean baseline data set after removing statistically significant or positive outliers.

The control limits are +/- 0.44 pCi/L based on the average 2-a standard deviation of the limiting mean. Results with concentrations greater than 0.52 pCi/L were determined to be statistically different from the underlying background based on outlier testing. It is easy to visually identify the transition from the underlying background data to the statistically significant data in Figure 5-11. Note that forty (40)44 of the fifty-two (52) reported Sr-90 results for this data set were greater than the zero concentration.

The baseline Sr-90 data consisted of 41 data points and were normally distributed around the limiting mean value of 0.14 pCi/L as indicated in Figure 5-12. The baseline limiting mean value was statistically greater than zero based on the t-test. These results are typical of GPC analysis where a positive systematic bias in the underlying baseline distribution exists.Similar results were obtained for gross alpha and gross beta analyses performed via GPC. In the case of gross alpha and gross beta, the positive trends observed in these analyses, is actually attributed to natural levels of gross alpha and beta radioactivity.

5.2.8.4 HTD Alpha Emitters Figure 5-13 is a rank order plot of Cm-242 concentrations in groundwater for the fourth quarter 2004 sampling event. Curium-242 is an alpha emitter with an expected low radionuclide inventory at HNP due to radioactive decay. Curium-242 has a radioactive half-life of 163.2 days and has decayed through greater than 14 half-lives since shutdown.

Since less than 0.01% of the shutdown activity or inventory remains, Cm-242 is not expected to be present in detectable quantities in groundwater samples from the HNP.An average and 1-a standard deviation concentration of 0.019 +/- 0.033 pCi/L was observed in this data set while the average MDC was 0.23 pCi/L. The control limits are+/- 0.066 pCi/L based on 2-a standard deviations of the limiting mean. Note that the individual 2-sigma error bars generally span the region of the control limits except in the negative regions of the graph. Here the 2-a error is underestimated due to the presence of zeros in the analytical counting results. This is characteristic of low-level alpha counting where zero results are sometimes observed (i.e., zero counts observed in the detector region-of-interest) during the finite counting interval.The baseline data are normally distributed around the limiting mean value of, 0.018 pCi/L in Figure 5-14 and the limiting mean value is not statistically different from zero, based on the t-test. Low-level counting data are not always expected to be normal, around a limiting mean value. This is a characteristic of low-level alpha counting where the expected shape of the limiting mean distribution is Poisson in nature. The Poisson distribution is asymmetric and representative of a distribution that is bounded by zero on the low frequency side. As expected, no significant Cm-242 activity is indicated in this trend plot. These results are typical of low-level alpha isotopic analysis where no analyte is present.Figure 5-15 is a rank order plot of Am-241 concentrations in groundwater for the Fourth quarter 2004 sampling event. Americium-241 is an alpha emitter that has been detected in HNP process streams attributed to failed fuel. An average and 1-a standard deviation concentration of 0.027 +/- 0.040 pCi/L was observed in this data set while the average MDC was 0.28 pCi/L. The control limits are +/- 0.080 pCi/L based on the average 2-a 45 standard deviation of the limiting mean. Note that the individual 2-sigma error bars generally span the region of the control limits.The data are normally distributed around the limiting mean value of 0.027 pCi/L in Figure 5-16. The limiting mean value of 0.027 pCi/L is not statistically greater than zero analyte level based on the t-statistic and 17 (n-1) degrees of freedom. Note that a slight elevation in Am-241 activity is indicated in this trend plot as compared to the Cm-242 trend plot and as fifteen (15) of nineteen (19) results are greater than zero concentration.

No significant positive trends were observed with other alpha isotopic data.In the past CYAPCo lab vendors have had some minor difficulties with "false positive" detects for Am-241 during the course of performance evaluation (PE) testing. It is important to note that Am-241 is a common alpha-emitting radiotracer used in the radiochemistry lab. Solid-state alpha detectors are subject to recoil contamination after repetitive source and sample analysis.

Alpha recoil contamination, which increases the detector background, occurs when fragments from the source or sample are implanted in the detector surface, by the recoil energy imparted on the nucleus of an alpha-emitting atom. Solid-state alpha detector background rates are extremely low, typically on the order of 1 count per 100,000 seconds. Given typical sample analysis parameters and the sensitivity requirements for these analyses, the ability to accurately distinguish sub-pCi/L amounts of Am-241 groundwater from the detector background contribution is non-trivial.

These results are typical of low-level alpha isotopic analysis where the underlying baseline distribution is subject to large fluctuations due to the extremely low ambient background count rate.5.2.8.5 Radiochemical Bias Summary Attached in Table 5-14 is a summary of the percentage of positive results detected at concentrations that were greater than 2-ca random error and near the MDC level. This table provides an indication of the percentage of false positive results as a function of analysis method. Known statistically positive results were removed from these summaries.

Only about 3.9% of the gamma isotopic analysis results were greater than the 2-ca random error level, which is just slightly higher than the expected rate of 2.5% if there were no significant gamma emitters present..

One would expect a "false positive" rate of 2.5% based on the area under the standard normal distribution around a limiting mean concentration of zero, at the 95% confidence level. These results suggest that there is little bias in the gamma isotopic analytical results at levels near the MDC, and there is little gamma isotopic activity in these samples.Alpha isotopic results for the third and fourth quarter 2004 sample events indicated overall positive activity rates of 0.8%, which also indicates no significant alpha activity present in these samples with minimal bias in the analytical technique at levels near the MDC.The percentage of HTD beta results determined via LSC and with concentration levels greater than 2-a random error was 6.7%. These results were generally normally distributed around a limiting mean concentration in most cases. Only 2 of the 12 LSC 46

--analyses (by nuclide) indicated limiting mean distributions that were positive.

Negative limiting mean distributions were not observed for any of the LSC analyses.Factors that may affect the uncertainty of radiological analyses, and the ability to discern plant-related activity from the natural background activity include; interference from naturally occurring radionuclides due to incomplete radiochemical separation, specificity of radiochemical counting technique, and difficulty in identifying the ambient background or blank contribution.

In low-level radiochemical counting, these limitations are imposed by the accurate determination of the systematic and random uncertainty associated with the analytical blank. Generally speaking, gamma isotopic and alpha isotopic analyses are the most specific counting methods with the least amount of systematic bias in the underlying background or blank. GPC and LSC are less specific counting methods and may be subject to systematic and random variability in the underlying blank distribution.

CYAPCo will continue to statistically evaluate and trend lab data in order to understand limitations and irregularities in analytical results.Based upon the work performed during the implementation and development of this Groundwater Monitoring Report for the third and fourth quarter 2004 quarterly sampling events, the following conclusions and recommendations have been developed for the radiochemical analyses presented in this report:* Systematic biases were observed in several of the HTD analyses based on statistical and graphical evaluations of the reported analytical data. Negative biases, which have been observed in the past for radionuclides analyzed by LSC, were not observed in any of the sample event data sets.* Positive systematic biases were observed in several of the HTD analyses by LSC and GPC. The affected analyses included gross beta, H-3 and Sr-90. An overall false positive rate on the order of 6.7% was observed for the LSC analyses results. This is higher than the expected false positive rate of 2.5%.* A positive bias was also observed for Co-60 which is a gamma emitter. This positive bias was not based on baseline trend analysis but based on reanalysis requests that were not substantiated in the follow-up analyses.

CYAPCo will continue to statistically evaluate and trend the biases identified within this report.* Field collected and laboratory completed QA/QC sample results were within acceptable protocol ranges for all analyses.* External laboratory performance evaluation data was excellent for all gamma emitters and good to average for the alpha and beta HTD analysis.

Less than 67% of the false positive test results were in the acceptable or acceptable with warning range.* Internal laboratory performance evaluation data was excellent for all analyses.Greater than 98% of the results met the acceptance criteria.5.3 Data Quality Summary Analysis of boron and radiochemical constituents was performed on unfiltered water samples collected from groundwater monitoring wells at HNP during the third'and fourth quarter of 2004. In addition, filtered samples were analyzed for geochemical constituents at several locations during the third quarter 2004 sampling round.47 Geochemical groundwater samples were field filtered using 0.45 micrometer in-line filters prior to preservation.

Overall, assessments of QA/QC information indicate that groundwater monitoring data are acceptable for groundwater characterization and monitoring efforts. Groundwater sampling was performed in accordance with sample plans and work processes.

No contamination or other sampling-related problems were identified that affected data integrity in the field. Laboratory external performance data was good to excellent for all constituents.

MAPEI? performance results for false positive testing requires some improvement.

Laboratory internal performance data was good to excellent for all constituents but boron, which requires improvement.

Measurement of boron, geochemical and radiochemical constituents in samples collected from HNP met the identified data quality metrics for these sampling events.48 6 Spatial and Trend Analysis 6.1 Spatial Distribution of SOCs The spatial distribution of detected SOCs (boron, tritium, Sr-90) have been mapped for the perched, unconfined and confined aquifers for the third and fourth quarter 2004 sampling events, and are summarized below.There is uncertainty in mapping groundwater flow and contaminant distribution in fractured rock. The maps of contaminants and the text discussing spatial distribution is intended to show general distribution of contaminants; actual flow through the fractured rock may vary significantly from that depicted and discussed.

The inferred distribution of SOCs represents interpretations of site conditions.

6.1.1 Spatial Distribution of SOCs from Third Quarter 2004 The concentrations of boron, tritium, and, Sr-90, for the third quarter 2004 sampling results for the industrial area and peninsula area are displayed on Figures 6-1, 6-2 and 6-3. A discussion of the distribution of the SOCs in each aquifer is presented in the following sections.6.1.1.1 Boron Boron is detected in the three aquifers at concentrations ranging from 5.2 pg/L up to 581 pg/L. There is no MCL or CTDEP Remediation Standard Regulation (RSR) established for boron, however criteria is currently being evaluated by the CTDEP as part of the ongoing RCRA CAP and Property Transfer program. Boron will be assessed against RSR criteria as part of the RCRA CAP/Property Transfer program. In the context of this report boron is used as an indication of plant-related contamination and also as an effective tracer of potentially contaminated groundwater.

A discussion of the boron distribution in groundwater for the three aquifers is presented in the following sections.Perched Aquifer Boron in the perched aquifer ranges from 58 pg/L to 65.5 pg/L in perched wells MW505, MW507S, and MW508S (Figure 6-2). Due to it's high water level, MW104S is included in the perched aquifer, and is located near the eastern edge of the aquifer. The boron concentration in MW104S is significantly higher (268 pg/L) than that observed in the other perched wells and is consistent with the boron distribution observed in the unconfined aquifer. Likewise, MW104S is located near the eastern edge of the swampy deposits and is screened in both the unconsolidated material and the shallow bedrock below. Based on the elevated boron and the screened interval for MW104S, the monitoring well is included in the SOC distribution for the unconfined aquifer. Aside from MW104S, boron concentrations in the perched are interpreted as background, and indicate that no impacts from plant activities are apparent in the perched aquifer.49 Unconfined Aquifer A large area of elevated boron is observed in the unconfined aquifer from upgradient portions of the site (MW100S) to downgradient areas of the site (MW11OS) (Figure 6-4).In the unconfined aquifer boron concentrations appear highest around the southern perimeter of the RCB in MW106S (581 pg/L), with plume concentration decreasing to the south and southeast (Figure 6-4). As discussed in Section 2, the discharge tunnel is located south of the RCB and forms a barrier for flow in the unconsolidated portion of the unconfined aquifer. In the area of the discharge tunnel, groundwater flow in the shallow portion of the unconfined aquifer is redirected to the southeast where the tunnel base is no longer on/in bedrock. East of the discharge tunnel the unconsolidated unit thickens considerably, and groundwater flow in the unconsolidated and shallow bedrock of the unconfined aquifer continues due south toward the Connecticut River (Figures 6-4 and 2-6). The effects of the discharge tunnel are clearly reflected in the boron distribution as the boron plume id deflected to the southeast by the tunnel and continues to the south and southeast towards the Connecticut River (Figure 6-4).While the source of the highest boron concentrations is focused on the RCB area, elevated boron is also observed in the western portion of the industrial area (MW104S;268 Vg/L, MW124; 244 pg/L, and) and upgradient of the RCB area (MW1OOS; 151 Pg/L and MW1O1S; 144 pg/L) (Figure 6-4). Likewise, these monitoring wells do not typically have elevated tritium concentrations that are present in monitoring wells in the RCB area (Figure 6-1). The elevated boron observed in the upgradient and western monitoring wells in this portion of the site may indicate another source (i.e., warehouse storage areas or an historic spill) for boron in the western portion of the unconfined aquifer.Elevated boron is also detected in MW113S (130 pig/L) located south of the discharge canal in the southeaster portion of the site (Figure 6-4). This location is well south and east of the mapped boron plume, but is adjacent to septic leaching beds that may be releasing boron to the shallow groundwater in that area.Confined Aquifer In the confined aquifer boron is detected in both the western and eastern portions of the industrial area (Figure 6-5). Elevated boron is detected in MW109D (184 pg/L) and MW123S (134 pg/L) located in the western portion of the industrial area (Figure 6-5).Boron is also detected in a plume extending south from MW102S (174 jig/L), past MW122D (264 pg/L), and on to MW11OD (400 pig/L) in the eastern portion of the industrial area (Figure 6-5). Both areas of detected boron appear to flow from north to south towards the Connecticut River (Figure 6-5).The highest concentrations of boron in plume on the eastern side of the industrial area occur in the downgradient portion of the plume, and higher boron concentrations have been historically observed in the upgradient wells (MW102D and MW122D) associated with the plume. This suggests that a slug of elevated boron has historically migrated through this portion of the industrial area towards the Connecticut River.A second, lower concentration plume occurs in the western portion of the industrial area. Elevated boron concentrations are observed in MW123 (134 Pg/L) and MW109D (184 pg/L). Elevated boron was observed in this portion of the site in previous studies.50 These monitoring wells form a second plume of elevated boron that flows towards the Connecticut River (Figure 6-5).6.1.1.2 Tritium Tritium is detected in the three aquifers at concentrations ranging from non-detect up to 31,000 pCi/L. All detections in the three aquifers are below the C4 concentration for tritium of 20,OOOpCi/L except for MW103S where 31,000 pCi/L was reported.Perched Aquifer Tritium results in the perched aquifer were all non-detect (Figure 6-2). Consistent with the low, background boron detections, the tritium distribution also indicates no impacts from plant activities in this portion of the site.Unconfined Aquifer In the unconfined aquifer (Figure 6-6), tritium was detected above activity concentrations of 1,000 pCi/L in several locations.

The highest tritium levels in the unconfined aquifer occur in MW103S (31,000 pCi/L) and MW102S (12,600 pCi/L).(Figure 6-6). Elevated tritium flows to the southwest and southeast from the RCB area (Figure 6-6). The plume to the southwest of the RCB flows towards MW124 (2,080 pCi/L). This area of elevated tritium is downgradient of the RCB and an area of elevated tritium that was formerly associated with abandoned well MW105S, and is believed to flow from the RCB area around the northwest end of the discharge tunnel (Figure 6-6). This plume of tritium-contaminated groundwater would be expected to flow to the south towards the Connecticut River (Figure 2-6).The second plume of tritium flows from the RCB southeastwards around the eastern end of the discharge canal and towards the Connecticut River (Figure 6-6). This plume of elevated tritium includes monitoring wells MW106S (1,260 pCi/L), MW125 (2,390 pCi/L) and MW11OS (1,670 pCi/L) and is interpreted to flow from the RCB, past the discharge canal, and towards the Connecticut River (Figures 6-6 and 2-6).Confined Aquifer In the confined aquifer, tritium is detected adjacent to the northwest side of the RCB in MW103D (8,950 pCi/L) and northeast of the RCB in MW102D (5,120 pCi/L) (Figure 6-7).Based on the groundwater contour maps for the confined aquifer, it appears that groundwater flows from the RCB area, and then continues south toward the Connecticut River, passing through the area of MW106D (2,700 pCi/I), MW11OD (13,600 pCi/L) and MW109D (3,480 pCi/L) Figures 6-7 and 2-7). The elevated concentration of tritium observed in MW11OD, relative to the lower upgradient concentrations mapped in the plume, suggests that a slug of higher concentration tritium-contaminated groundwater has passed through this downgradient portion of the site in the past. The monitoring wells downgradient of the RCB area in the confined aquifer appear to be part of the tritium plume that is sourced in the RCB area. The general groundwater flow direction in the confined aquifer is to the south and southeast towards the Connecticut River (Figure 2-7).51 6.1.1.3 Strontium-90 K> Sr-90 is detected in both the unconfined and confined aquifers at concentrations ranging from non-detect up to 7.3 pCi/L. The C4 concentration for Sr-90 is 8 pCi/L and all reported Sr-90values in the monitoring wells are below the C4 value.Perched Aquifer Sr-90 was not analyzed in any of the monitoring wells included in the perched aquifer except for MW104S located on the eastern edge of the perched aquifer. As discussed in Section 6.1.1.1, the boron concentration in MW104S is more consistent with the distribution observed in the unconfined aquifer. Thus, the non-detect Sr-90 concentration reported in MW104S most likely does not characterize the perched aquifer.Unconfined Aquifer In the unconfined aquifer the highest Sr-90 is detected in MW106S (7.3 pCi/L) located adjacent to the southern side of the RCB (Figure 6-8). Additional detected Sr-90 occurs in MW103S (3.67 pCi/L), MW125 (1.93 pCi/L), and MW122S (1.23 pCi/L). MW125 is located southeast and downgradient of MW106S (Figure 6-8 and 2-6), while MW -123S MW103S, and MW122S are located to the west, north, and east of the RCB, respectively (Figure 6-8). The highest Sr-90 concentration is located adjacent to the RCB, which appears to be the source area for the Sr-90 detections.

Based on the groundwater flow map developed for the unconfined aquifer and similar to the plumes mapped for tritium and boron in the unconfined aquifer, it appears that the Sr-90 is migrating around the eastern edge of the discharge tunnel and flowing south toward the Connecticut River (Figures 6-8 and 2-6).Confined Aquifer In the confined aquifer Sr-90 is detected in one monitoring well (MW123S, 0.55 pCi/L), located west of the RCB and PAB (Figure 6-9). Based on the limited data available in the vicinity of the RCB and the PAB in this aquifer and the non-detect values in all of the other monitoring wells, no distinct plume can be mapped in the confined aquifer.6.1.2 Spatial Distribution of SOCs from Fourth Quarter 2004 The concentrations of boron, tritium, and Sr-90 for the fourth quarter 2004 sampling results for the industrial area, EOF, parking lot, peninsula area, and landfill area are displayed on Figures 6-10, 6-11, 6-12, and 6-13. A discussion of the distribution of the SOCs in each hydrostratigraphic unit is presented in the following sections.6.1.2.1 Boron Boron is detected in the three aquifers at concentrations ranging from 11.2 jg/L up to 802 jpg/L. There is no MCL or CTDEP Remediation Standard Regulation (RSR)established for boron, however criteria is currently being evaluated by the CTDEP as part of the ongoing RCRA CAP and Property Transfer program. Boron will be assessed against RSR criteria as part of the RCRA CAP/Property Transfer program. In the context of this report boron is used as an indication of plant-related contamination and also as an effective tracer of potentially contaminated groundwater.

A discussion of boron in the three aquifers follows.52 Perched Aquifer Boron in the perched aquifer ranges from 57 pg/L to 80 pg/L in MW505, MW507S, and MW508S (Figure 6-11). Similar to the third quarter results, the boron concentration in MW104S is consistent with the distribution mapped for the unconfined aquifer. Aside from the boron observed in MW104S, the low boron concentrations are interpreted as background, and generally indicate that no impacts from plant activities are apparent in the perched aquifer.Unconfined Aquifer In the unconfined aquifer (Figure 6-14), boron concentrations appear highest around the perimeter of the RCB. The highest boron concentration occurs in MW106S (802 pg/L)located adjacent to the southeastern portion of the RCB. Elevated boron concentrations also occur in EP-171 (364 pg/L), EP-166 (157 ,tg/L) located west of the RCB, and CMS (111 pg/L) MW122 (187 pg/L) east of the RCB (Figure 6-14). Consistent with the groundwater flow contours in the unconfined aquifer, a plume of boron occurs to the south and east of the RCB with concentration decreasing to the south toward the Connecticut River (Figures 2-9 and 6-14). The boron distribution in the southeastern, downgradient portion of the plume is characterized by MW125 (308 Vg/L) and MW11OS (281 pg/L).MW1OOS is well upgradient of the RCB and has elevated boron (109 pg/L), but no other SOCs. Similarly, the monitoring wells downgradient of MW100S along the western portion of the boron plume (MW104S (172 gg/L) MW124 (258 pg/L)) are not associated with elevated tritium or other radionuclides suggesting a source other than borated water from the power plant for the elevated boron on the west side of the plant (Figure 6-14).Similar to that observed in the third quarter, elevated boron is also detected in MW113S (106 pg/L) located south of the discharge canal in the southeaster portion of the site (Figure 6-14). This location is well south and east of the mapped boron plume, but is adjacent to septic leaching beds, that may be releasing boron to the shallow groundwater in that area.Confined Aquifer The distribution of boron in the unconfined aquifer unit defined by the fourth quarter 2004 data show a broad area of boron concentrations greater than 100 pig/L, but with no boron concentration greater than 176 jig/L (Figure 6-15). The area of elevated boron extends south from the RCB down to the Connecticut River, and appears to be sourced in the RCB area (Figure 6-15).The elevated boron in the wells in the western portion of the plume (MW123S; 113pjg/L)is not associated with other SOCs, suggesting a source other than borated water from the power plant process (Figure 6-15).53 6.1.2.2 Tritium All detections in the three aquifers are below the C4concentration for tritium of 20,000 pCi/L, and range from non-detect to 10,800 pCi/L. Elevated tritium concentrations are observed in both the unconfined and confined aquifers, with the highest concentration observed in the confined aquifer.Perched Aquifer Tritium results in the perched aquifer were all non-detect (Figure 6-11). Consistent with the low, background boron detections, the tritium distribution also indicates no impacts from plant activities in this portion of the site.Unconfined Aquifer Similar to the tritium distribution of tritium mapped from the third quarter 2004 results, the highest tritium concentrations are observed on the north and adjacent to the RCB in MW102S (8,930 pCi/L) and EP-171 (9,040 pCi/L) (Figure 6-16). The elevated tritium in the RCB area flows to southeast and southwest south of the RCB on both sides of the discharge tunnel (Figure 6-16). The southeastern plume flows east of the RCB near the CMS (3,260 pCi/L) and flows south, consistent with the mapped groundwater contours, through MW125 (861 pCi/L) and MW11OS (1,820 pCi/L) toward the Connecticut River (Figures 6-16 and 2-9).The second area of elevated tritium occurs west of the RCB in EP-171 (9040 pCi/L) and EP-166 (3,610 pCi/1), and also flows to the south towards the Connecticut River.Elevated tritium is also observed at MW124 (968 pCi/L) that appears to be in the downgradient portion of the plume mapped from the western side of the RCB (Figure 6-16 and 2-9).Confined Aquifer The tritium distribution in the confined aquifer defined by the fourth quarter 2004 data is very similar to that identified in the third quarter 2004 results (Figures 6-7 and 6-17).As depicted in the third quarter 2004 results, the highest tritium concentrations are observed north and northeast of the RCB in MW103D (10,800 pCi/L) and MW102D (6,480 pCi/L). The elevated tritium detected in the RCB area is mapped to the south through MW106D (3,670 pCi/L) and continuing on south through MW109D (3,390 pCi/L) and MW11OD (3,900 pCi/L) toward the Connecticut River, consistent with the mapped groundwater flow for the confined aquifer (Figures 6-17 and 2-10).6.1.2.3 Strontium 90 Sr-90 is detected in the both the unconfined and confined aquifers, with concentrations ranging from non-detect to 8.56 pCi/L. The C 4 concentration for Sr-90 of 8 pCi/L is exceeded in MW106S. The Sr-90 distribution in the three aquifers is discussed in the following sections.Perched Aquifer As with the third quarter 2004 results, Sr-90 was not analyzed in any of the monitoring wells included in the perched aquifer, except for MW104S located on the eastern edge of the perched aquifer. As discussed in Section 6.1.1.1, the boron concentration in MW104S is more consistent with the distribution observed in the unconfined aquifer. Thus, the 54 non-detect Sr-90 concentration reported in IvIW104S most likely does not characterize the perched aquifer.Unconfined Aquifer The highest Sr-90 concentrations in the unconfined aquifer are located adjacent to and south of the RCB (Figure 6-18). The highest Sr-90 concentration occurs in MW106S (8.56 pCi/L) with 2.43 pCi/L detected in the CMS located adjacent to the RCB (Figure 6-18).Sr-90 is also detected in MW125 (3.08 pCi/L) located southeast of the RCB. These three monitoring wells with detected Sr-90 form a plume of Sr-90 that flows south from the RCB area towards the Connecticut River (Figures 6-18 and 2-8). All other monitoring wells screened within the unconfined aquifer are non-detect for Sr-90 Confined Aquifer Sr-90 was detected in only one monitoring well in the unconfined aquifer. The CMS located east and adjacent to the RCB had 2.43 pCi/L (Figure 6-19). All of the other monitoring wells were non-detect for Sr-90.6.1.3 Distribution of SOCs from the Landfill Area The distribution of SOCs in the Landfill Area is consistent with no impacts from the industrial portion of the property.

The landfill area is upgradient of the industrial area, and both Sr-90 and tritium are non-detect in all landfill area monitoring wells (Figure 6-13). Boron concentrations range from 10.7 pg/L to 57 pg/L (Figure 6-13), consistent with a background distribution.

Both the non-detect Sr-90 and tritium concentrations and background boron distribution, indicate that the industrial area has not impacted the landfill area.6.1.4 Distribution of SOCs from Seep Sampling A total of six seeps have been sampled from November 2004 through February 2005.These seeps are located in the industrial area in the vicinity of the former PAB building (Figure 2-12). As discussed in Section 2.3, the seeps began flowing in late fall 2004 following the excavation of the soil that exposed bedrock in the PAB area and groundwater pumping that drew down the unconfined water table in that area. A complete set of analyses for the seep water has been performed for four of the seeps, and consistent detections of boron, tritium, and Sr-90 have been reported in the seep samples. The following sections summarize the seep results.6.1.4.1 Boron Boron was analyzed in Seeps 1 through 4 in both January and February 2005. The seep results are included in Table 6-1 and boron concentrations have ranged from 117 Pg/L to 567 pg/L. The highest boron concentrations have been reported in Seeps 1 and 2 where boron concentrations have ranged from 505 pg/L to 567 pg/L. These two seeps are only several feet apart and most likely are sampling the same groundwater.

Lower boron concentrations are observed in both Seep 3 (117 pg/L to 261) and Seep 4 (351 pg/L to 415 pg/L) and these two seeps appear to sample different groundwater relative to Seeps 1 and 2.55 6.1.4.2 Tritium Tritium was analyzed in the four seeps in both January and February.

2005, and concentrations ranged from non-detect to 3,250 pCi/L (Table 6-1). Similar to the boron results, the highest tritium concentrations were observed in Seep 1 and 2 (2,660 pCi/L to 3,250 pCi/L). The lowest tritium levels were reported in Seep 3 (non-detect to 1,510 pCi/L), with slightly higher tritium concentrations in Seep 2 (2,370 pCi/L to 2,370 pCi/L). Consistent with the boron results, the lower tritium levels in Seeps 3 and 4 suggest that these seeps are sampling different groundwater than Seeps 1 and 2.6.1.4.3 Strontium 90 Sr-90 was analyzed in the four seeps in November 2004 and January and February 2005.Consistent with the boron and tritium results, the Sr-90 values in Seeps 1 and 2 were very similar with concentrations ranging from 22.3 pCi/L to 25.6 pCi/L (Table 6-1).Much lower values were detected in Seep 4 with Sr-90 ranging from non-detect to 2.93 pCi/L. The Sr-90 values in Seep 3 varied through time. Initial concentrations measured in November 2004 were low (4.81 pCi/L). Sr-90 in Seep 3 increased to 9.86 pCi/L in January 2005, further increased to 17.2 pCi/L in early-February 2005, and decreased to 4.63 pCi/L in mid-February.

The results from Seep 4 are in contrast to the consistent and high Sr-90 values observed in Seeps 1 and 2 and the consistent low Sr-90 levels observed in Seep 4. The Sr-90 seep results also show that Seeps 1 and 2 are sampling groundwater very different from that associated either Seep 3 or 4.The presence of the SOCs in the seeps, especially the elevated Sr-90 concentrations suggest that a potential source of groundwater contamination is present in the nearby locality of the seeps. The long-term and consistent elevated concentration of Sr-90 in Seeps 1 and 2 further suggest that the source for the seeps may be contaminated soil with sorbed concentrations of Sr-90, boron, and tritium. Additional characterization is underway to address this potential contamination source.6.1.5 General Geochemistry Across the Site In addition to the SOC analysis, monitoring wells sampled in the third quarter were also analyzed for major dissolved ions (i.e., calcium, magnesium, sodium, potassium, chloride, sulfate, carbonate, bicarbonate).

The analyses were performed on field-filtered samples and results are included in Table 4-9. The analytical results were generated in mass concentration units (i.e., mg/L). To evaluate the analytical results for the dissolved ions, the mass concentrations were converted to equivalent concentrations (i.e., eq/L) by dividing the mass concentrations by the respective ionic equivalent weights. The equivalent concentrations were then plotted using the "radar plot" function in Microsoft ExcelTM to create the comparative diagrams shown in Figures 6-20 through 6-24. Radar plots for individual wells are also presented in Appendix F. The major ions were previously analyzed in selected monitoring wells in December 2003. Where multiple rounds of analyses are available for individual wells, both sampling rounds for each well are presented on a single radar plot for the well (Appendix F). Due to similarity in ion distribution patterns, all of the wells located at the HNP landfill area are included in a single plot (Figure 6-20). Selected wells in the HNP industrial area were identified for 56 comparisons between wells identified as "deep" and "shallow" and upgradient and downgradient.

The wells located at the facility landfill area appear to be consistent in ion distribution and of very low total dissolved ion concentration (Figure 6-20 and Table 4-9). Based on the low total ion concentrations, the consistent distribution of ions, and the general upgradient location of the landfill relative to the industrial area, these wells may be considered to be unimpacted by industrial activities and are likely representative of the"pristine" groundwater condition for site groundwater.

In the 2004 data set, selected wells in the developed portion of the plant site (i.e., MW1OS, MW1OD, MW100D, MW1OOS) share a similar ion distribution and magnitude to the landfill wells and also appear to represent a "pristine" groundwater condition (Figure 6-21). The wells that may be considered "pristine" are all located on the inland and up-gradient (relative to groundwater flow) side of the plant (Figures 2-6 and 2-9).Monitoring wells MW111 and MW112 also exhibited ion characteristics similar to the"pristine" wells when sampled in December 2003 (Figure 6-21). These two wells are located adjacent to the river on the downgradient side of the Plant, but are located in the eastern portion of the site and are not downgradient of the industrial area (Figures 2-6 and 2-9).The remaining wells located down-gradient of the inland wells and directly within or downgradient of the industrial area of the plant typically exhibit generally increased relative concentrations of calcium and chloride, consistent with historical, and continuing, application of road salt for control of ice in road and walk ways (Figure 6-22). Selected wells also exhibit increased relative concentrations of magnesium and sodium, also consistent with application of road salt (Appendix F).Calcium chloride, magnesium chloride and sodium chloride have all been used for ice control at HNP. The apparent impact of salt on groundwater ion concentrations is also greater in the wells identified as "shallow" than in the "deep" wells, as would be expected from surface application of the various salt compounds (Figures 6-23 and 6-24).The observed changes in ion concentration from upgradient to downgradient along with the greater impact of shallow relative to deeper wells indicates that the salting activities within the industrial area at the plant contribute to the ion distribution in groundwater.

Comparison of the 2003 and 2004 data sets indicates substantial seasonal variability in ion concentrations in many wells, while the shape of the shape of the ion distribution displayed in the radar plots was typically similar from the two sampling rounds (Appendix F). These seasonal changes are interpreted to be a function of dilution and varied seasonal application of the salts.57 6.2 Trend Analysis of SOCs 6.2.1 Boron Trend Analysis There has been a general decrease in the observed maximum boron concentration at HNP since September 1999. Boron concentrations have generally fluctuated over the time-frame of the GWMP without any discernable temporal or spatial trends. The boron quarterly monitoring analytical results from September 1999 through December 2004 are summarized in Table 4-1. Time series plots of the boron concentrations from September 1999 to December 2004 are provided in Appendix G.The higher boron concentrations have generally been detected in the shallow wells, typically those wells screened in the unconfined aquifer. Boron levels in deep bedrock or confined aquifer wells have typically been relatively low compared to wells completed in shallower intervals, probably reflective of background concentrations.

This generalization is well illustrated by the time series plot of well pair MW1OOS and 100D. Boron concentrations that have fluctuated greatly in MW100S, screened in the unconfined aquifer, ranging as high as 1,145 pg/L as recently as December 2003, to a stable trend of non-detections exhibited in MW1O0D, a deep bedrock or confined aquifer well. Similar trends are also shown in the MW105S/D andMW106S/D well pairs, both of which have shown greatly elevated boron concentrations in the shallow unconfined aquifer wells and low boron levels in the deep bedrock wells probably near background concentrations.

Attached in Figure 6-24 is a box plot for boron concentrations as a function of time ranging from September 1999, through December 2004. Box plots provide a mechanism to graphically compare 2 or more sets of data, in this case, temporal or seasonal groundwater monitoring results from multiple quarterly sampling events. In particular, trends with respect to the median, extreme values'and data dispersion over time are visually evident. The median value provides an unbiased central tendency of the data that is not affected by extreme outliers.

The position of the median value in the vertical box provides information regarding the symmetry of the inter-quartile range when viewed on a linear scale. The inter-quartile range describes the spread of the central 50%of the data. The length of the vertical boxes shows the extent of the inter-quartile range.The length of the vertical lines or whiskers shows the overall extent of the data above and below the inter-quartile range. We have selected a log concentration scale since the detectable concentrations ranged over 2 or more orders of magnitude.

The box plot displays a quartile summary of quarterly sample event data with some key statistics.

The quarterly sample event results are sorted in increasing numerical order and divided into 2 groups at the median or second quartile (Q2). The median of the lower group is the first quartile (Q') and the median of the upper group is the third quartile (Q3). The difference between Q3 and Q. is the inter-quartile range and is represented by the central vertical box or rectangle in the box plot diagram. The horizontal line dividing the central vertical box is the second quartile (Q2) or median value of the data set. The two lines extending out from the center box are the whiskers 58 and the end points in this case represent the minimum or zero quartile (Qo) and maximum or fourth quartile (Q4) values.The plotted values in Figure 6-24 display results for all wells sampled during the sampling event with concentrations greater than the method detection limit (MDL).There has been a general decrease in the observed maximum boron concentration since September 1999. Median results have fluctuated from a low of about 45 Pg/L in December 2001 to a high of 188 pg/L during September of 2002 with no apparent temporal or seasonal trend.6.2.2 Gross Alpha Trend Analysis Gross alpha concentrations for the past 10 sample events for unconfined and confined aquifer wells are plotted in Figures 6-25 through 6-26. Higher gross alpha levels were generally detected in the deeper wells completed in bedrock during these sampling events (Figure 6-26). The source of most of the activity is erosion of naturally occurring alpha-emitting nuclides that are likely present in the granitic gneiss bedrock. Natural levels of gross alpha activity can range as high as a few hundred pCi/L, when special sampling techniques designed to capture the volatile and short-lived natural alpha emitters are observed.

Although it is possible that plant-related radionuclides contribute to some of the observed gross alpha activity, it is not probable since alpha isotopic analysis generally results in non-detects with nominal detection sensitivity on the order of 0.3 pCi/L or less.Figure 6-27 is a box plot for site-wide gross alpha concentrations as a function of time ranging from December 2001, through December 2004. Plotted values in this case represent statistically significant results with concentrations greater than the 2-a TPU.The maximum gross alpha concentration has ranged from 7.8 to 40.8 pC/L since December of 2001. Median results have fluctuated from a low of 1.3 pCi/L to a high of 5.1 pCi/L. There were no apparent temporal or seasonal trends.6.2.3 Gross Beta Trend Analysis Gross beta results since 1999 are summarized in Table 4-2. Gross beta results ranged from 1.6 to 490 pCi/L. The CT Public Drinking Water Quality Standard screening level for gross beta radioactivity is 50 pCi/L, though natural levels may range as high as a few hundred pCi/L.As shown on Table 4-2, gross beta activity at high levels roughly correlates with Sr-90 (a beta emitter) data, in that the highest concentration of Sr-90 is also found in MW105S.Another beta emitter which contributes to gross beta activity is Cs-137 and has been detected in MW102D, MW103S and MW115S. Table 4-2 shows that groundwater from these locations also has relatively high concentrations of gross beta activity.Gross beta concentrations from the past 10 sample events for the unconfined and confined aquifer wells are plotted in Figures 6-28 through 6-29. All 3rd quarter and 4th quarter gross beta results are less than the CT Public Drinking Water Quality Standard screening level of 50 pCi/L.59 Figure 6-30 is a box plot for site-wide gross beta concentration as a function of time ranging from December 2001, through December 2004. The maximum gross beta concentration has ranged from 142 to 490 pC/L, since December of 2001. Median results have fluctuated from a low of about 5.4 pCi/L, to a high of 10.0 pCi/L. There are no apparent temporal trends associated with gross beta results.6.2.4 Tritium Trend Analysis There has been a general decrease in tritium activity concentrations at HNP since the quarterly GWMP sampling was implemented in September 1999. A summary of tritium results from the GWMP is provided in Table 4-3. The higher tritium activity concentrations have typically been exhibited in the confined aquifer wells, notably deep bedrock wells MW102D and MW103D, and shallow bedrock well MW11OD. MW105S, a well screened in the unconfined aquifer, has historically displayed the highest tritium activity concentrations at the facility.

None of these confined aquifer wells detected tritium above the EPA MCL of 20,000 pCi/L during the September and December 2004 sampling events. Time series plots showing tritium activity concentrations from the GWMP quarterly sampling events are shown in Appendix H.Historically, the highest tritium activity concentration observed at MW102D was 28,630 pCi/L during the June 2003 sample event (see Figure 6-31). Tritium results for MW102D ranged from 5,120 to 6,480 pCi/L, in September and December 2004, respectively, suggesting consistent concentrations at this well over the last 5 sample events. This well is a confined aquifer or deep bedrock well, which has exhibited fairly stable tritium concentrations in the 20,000 pCi/L range over the sampling events prior to December 2001.Since December 2001, tritium levels in MW103D have consistently ranged from 8,100 pCi/L to 12,900 pCi/L (see Figure 6-32). Analytical results for MW103D ranged from 8,950 pCi/L during the September 2004 event to 10,800 pCi/L during the December 2004 event.Tritium levels in well MW11OD have decreased substantially from the 27,630 pCi/L detected when quarterly monitoring commenced in September 1999. In December 2002, tritium levels decreased to 11,100 pCi/L (see Figure 6-33). Results have ranged from 8,300 pCi/L in September 2004, to 13,600pCi/L, during the December 2004 sampling event.The highest tritium concentration recorded to date was 138,700 pCi/L at well MW105S during the September 1999 sampling event. There has been a significant downward trend in tritium concentrations at this well with results ranging from 5,520 to 3,280 pCi/L during the March and June sampling events (see Figure 6-34). This well was physically removed from the monitoring network in August 2004 as part of the PAB excavation.

There has been an upward trend in tritium concentrations at MW114S with results ranging from 1,350 to 6,730 pCi/L during the March and June 2004 sampling events (see Figure 6-35). No samples were collected at this location during the third and fourth quarter due to site dewatering activities.

60 Tritium concentrations from the past 10 sample events for the unconfined and confined aquifer wells are plotted in Figures 6-36 and6-37. With the exception of well MW102D and MW103S, all H-3 results during these sample events were less than the EPA MCL of 20,000, pCi/L.Figure 6-38 is a box plot for site-wide H-3 concentrations as a function of time ranging from September 1999, through December 2004. Maximum H-3 concentrations have ranged from 13,900 to 31,270 pCi/L since September of 1999. Median results from have fluctuated from a low of about 900 pCi/L to a high of 4430 pCi/L during this same period. There were no apparent seasonal trends in the median results.6.2.5 Strontium-90 Trend Analysis Table 4-2 summarizes Sr-90 concentrations from the quarterly sampling events.Historically, monitoring well MW105S has exhibited the highest concentration of Sr-90 (see Figure 6-39). Historically, Sr-90 results in MW105S have consistently exhibited the highest results before this well was removed from service due to PAB excavation activities.

Elevated Sr-90 concentrations have also been noted at MW106S (see Figure 6-40). Other wells where Sr-90 concentrations greater than the CRDL of 2 pCi/L included MW103S and MW104S (see Figures 6-41 and 6-42).Strontium-90 concentrations from the past 10 sample events for unconfined and confined aquifer wells are plotted in Figures 6-43 through 6-44. With the exception of well MW103S, MW105S and MW106S, all Sr-90 results for unconfined aquifer wells were less than the EPA MCL of 8.0 pCi/L. All results for confined or deep bedrock wells were less than the CRDL of 2 pCi/L and no result to date has exceeded this level.Figure 6-45 presents a box plot for site-wide Sr-90 concentration as a function of time ranging from December 2001, through December 2004. The maximum Sr-90 concentration has ranged from 69.7 to 197 pC/L, at MW105S, since December of 2001.Median results have fluctuated from a low of about 0.8 pCi/L to a high of 4.6 pCi/L.There were no apparent temporal or seasonal trends in the median values. There appears to be a seasonal trend in the highest values which all occur in MW105S. These maximum values levels tend to coincide with September and December sampling events, which are typically characterized by peak groundwater elevation levels.6.2.6 Cesium-137 Trend Analysis Cesium-137 was detected at statistically significant concentrations and greater than the MDC during the September and December 2004 sampling events. Table 4-2 summarizes Cs-137 analytical results in all wells since December 2001. Prior to the September and December 2004 sampling events, Cs-137 has been consistently identified in groundwater at location MW103S between a minimum of 8.39 pCi/L and a maximum of 87.6 pCi/L (Figure 646). MW103S is the shallow monitoring well in the cluster located in the vicinity of the former RWST. Cesium-137 has also been consistently detected at two additional monitoring wells, MW115S and MW102D. Cesium-137 has been detected in 61 MW115S in concentrations ranging from 1.6 to 7.59 pCi/L (Figure 6-47). Cesium-137 concentrations have ranged from 2.0 to 12.7 pCi/L in MW102D (Figure 6-48).Cesium-137 concentrations from the past 10 sample events for unconfined and confined aquifer wells are plotted in Figures 6-49 through 6-50. With the exception of well MW103S, all Cs-137 results during these sample events were less than the CRDL of 15 pCi/L. The EPA MCL for Cs-137 is 200 pCi/L and no result to date has exceeded this level. Combined time series plots for Sr-90 and Cs-137 are provided in Appendix I.6.2.7 Alpha Isotopic Analyses Americium-241 concentrations from the past 10 sample events for unconsolidated, shallow and deep bedrock wells are plotted in Figures 6-51 through 6-52. With the exception of well MW103D, all Am-241 results during these sample events were less than the CRDL of 0.5 pCi/L. The EPA MCL for alpha emitters is 15 pCi/L and no result to date has exceeded this level.6.3 Linear Regression Analysis 6.3.1 Sr/Y-90 + Cs-137 vs Gross Beta Figure 6-53 is a correlation plot of gross beta activity versus total Sr/Y-90 and Cs-137 concentration.

Only sample results with detectable Sr-90 or Cs-137 were used in this comparison.

Yttrium-90 (Y-90) is the radioactive decay product of Sr-90. Since the half-life of Sr-90 is significantly longer than Y-90, secular equilibrium is observed where both nuclides are characterized by the same concentration levels and the total concentration, denoted as Sr/Y-90, is doubled. A slope of 0.89 with a positive correlation coefficient (R) of 0.964 was observed (see Figure 6-54). The squared correlation term (R 2) was 0.929. These results suggest that Sr-90 and/or Cs-137 comprise at least 93% of the gross beta response at higher levels (i.e. greater than 25 pCi/L gross beta activity) and can be used to obtain screening or reasonable estimates of total Sr/Y-90 and Cs-137 in groundwater.

6.3.2 Total Uranium vs Gross Alpha Regression Analysis Figure 6-55 is a correlation plot of the total uranium concentration (ug/L) versus gross alpha concentration (pCi/L) in groundwater.

Only sample results with detectable total uranium and gross alpha activity were used in this comparison.

A positive correlation coefficient (R) of 0.92 was observed for the data set. The squared correlation term (R2)suggests that at least 84% of the gross alpha response can be attributed to the total uranium results.Figure 6-56 is a similar correlation plot of the total uranium concentration (pCi/L)versus gross alpha concentration (pCi/L). Total uranium concentrations were estimated as the product of the total uranium (pg/L) and the specific activity of natural uranium (pCi/jig).

Total uranium was assumed to be comprised of a natural mix of U-234, U-235 and U-238, with a U-234/U-238 ratio of 1.03, and a specific activity of 0.698 pCi/pg. The natural uranium radionuclides all decay by alpha emission with radioactive half-lives greater than 2.44 x 105 years. Only sample results with calculated total uranium concentrations greater than the average MDC of 1.7 pCi/L and detectable gross alpha 62 activity were used in this comparison.

Screening for gross alpha activity in the presence of high concentrations of salts and dissolved solids can result in erratic and anomalous results. For this reason, filtered samples with high concentrations of dissolved solids and unfiltered samples, which exhibited high concentrations of suspended solids or turbidity, were removed from this evaluation.

A slope near unity of 0.93 and a positive correlation coefficient (R) of 0.93 was observed for the data set (see Figure 6-56). The squared correlation term (R 2) was 0.86. These results suggest that at least 86% of the gross alpha response can be attributed to the total uranium results. These results suggest that gross alpha activity can be used to estimate levels of non-volatile, long-lived alpha emitters such as total uranium in groundwater, provided the necessary precautions for solids and dissolved solids are taken.6.3.3 K+ Ion vs Gross Beta Regression Analysis Figure 6-57 is a correlation plot of the K ion concentration (ug/L) versus gross beta concentration (pCi/L) in groundwater.

Only sample results from wells that did not contain Sr-90 or Cs-137 with detectable K+ ion and gross beta activity were used in this comparison.

A positive correlation coefficient (R) of 0.844 was observed for the data set.The squared correlation term (R2) suggests that at least 71% of the gross beta response, in the absence of Sr-90 and Cs-137, can be attributed to the K 4 ion results.Figure 6-58 is a similar correlation plot of the K+ ion as K-40 concentration (pCi/L)versus gross beta concentration (pCi/L). Potassium40 concentrations were estimated as the product of the Ki ion (ug/L) and the specific activity of natural potassium (pCi/ug).A natural potassium abundance of 0.0117% K40 with a specific activity of 0.698 pCi/ug was assumed. Potassium40 is a relatively energetic beta emitter with a radioactive half-life of 1.277 x 109 years. Only sample results from wells that did not contain Sr-90 or Cs-137, with calculated K-40 concentrations greater than the average gross beta MDC of 3.1 pCi/L and detectable gross beta activity, were used in this comparison.

A slope of 1.62 with a positive correlation coefficient (R) of 0.809 was observed (Figure 6-58). The squared correlation term (R2) was 0.734. These results suggest that in the absence of plant-related radionuclides, such as Sr-90 and Cs-137, at least 73% of the gross beta response can be attributed to the Ki ion as K40.63 7 Conclusions and Recommendations 7.1 Groundwater Quality Status The GWMP at the HNP provides the framework for data collection, quality assurance, and reporting groundwater quality status at the facility.

Analytical results from the quarterly sampling program implemented at the plant provide the data for comparing to standards, regulatory limits, and developing metrics for evaluating overall groundwater quality and potentially, plume status at the HNP.Groundwater contamination by plant-related SOCs has been observed in both the unconfined and confined aquifer units currently described at the facility.

The general configuration of contaminant plumes extend from the area immediately upgradient of the reactor containment building to the Connecticut River. The observed groundwater contamination at the plant appears to have originated from unplanned releases of contaminated process and wastewaters within the general vicinity of the reactor containment building, primary auxiliary building, and other facilities immediately surrounding the reactor containment building.Tritium, Sr-90, and boron account for the majority of the observed SOCs with less-frequent detections of Cs-137. Tritium, boron and Sr-90 are broadly distributed across the HNP industrial area. Although plant-related tritium concentrations in groundwater have declined substantially below the MCL in recent years, localized areas of other constituents (e.g., Sr-90) have remained relatively elevated.

Strontium-90 concentrations in localized areas between the containment building and primary auxiliary building, as exemplified by the observed concentration of Sr-90 in localized seeps, continues to exceed drinking water standards.

Although the maximum observed Sr-90 concentration currently exceeds the drinking water standard of 8 pCi/L groundwater contamination has declined substantially in the industrial area of the HNP since quarterly sampling began in 1999 (Appendices G through 1). Boron will be evaluated as part of the ongoing RCRA CAP and Connecticut Property Transfer Act investigations.

7.2 Contaminant Source Removal Effects Excavation of soil from the vicinity of the PAB, tank farm, and service alley has effectively removed a substantial portion of the previously identified contaminated soil that served as a secondary source of groundwater contamination.

This is evidenced by removal of the entire portion of the unconfined aquifer in the vicinity of the former well MW105S, which historically exhibited the highest Sr-90 concentration on site. Other previously identified soil contamination areas are yet to be removed (e.g., the soil surrounding the spent resin facility, the remainder of soil in the tank farm area, and other areas). In addition, the Sr-90 contamination exhibited by the bedrock seeps in the excavation area suggests the presence of additional secondary sources, most likely related to contaminated backfill soil in the central industrial area.64 7.3 Recommendations for Subsequent Sampling Events Based on the review of the results of the third and fourth quarter 2004 quarterly sampling and observed long-term trends in some wells, several recommendations concerning subsequent groundwater monitoring sampling events are suggested in this section. The recommended analytical suite for the upcoming first quarter 2005 GWMP quarterly sampling event should be the same as the one implemented for third quarter 2004. Specific recommendations are as follows:* Collecting paired filtered and unfiltered samples is not necessary based on the data reduction effort and evaluation of analytical results performed in previous reports.Unfiltered groundwater samples should be collected from all of the wells in the industrial area and analyzed for all constituents during the first quarter 2005 quarterly sampling event.* The "500" series wells located in the parking lot should be sampled and analyzed for the full suite of radionuclides on one occasion to confirm that they are not impacted by plant-related radionulcides.

  • Basic geochemistry analysis should be performed on the "500" series wells in the parking lot. This will require collection of field-filtered sample aliquots for analysis of cations and anions.* Monitoring of the groundwater seeps in the excavation area should be continued.
  • Sampling of the landfill wells should be suspended pending completion of soil remediation activities.

Othenvise, the wells sampled should remain the same as previous sampling rounds.65 8 References CY-ISC-SOW-2003 Statement of Work for Environmental, Bioassay and Waste Characterization Analytical Services, Revision 0, August 27, 2003 ERA RAD-49 ERA's RadChemThi Proficiency Testing Study RAD-49, July 2002 ERA RAD-50 ERA's RadChemmi Proficiency Testing Study RAD-50, November 2002 ERA RAD-51 ERA's RadChemTm Proficiency Testing Study RAD-51, January 2003 ERA RAD-52 ERA's RadChemTh' Proficiency Testing Study RAD-52, April 2003 ERA RAD-53 ERA's RadChemTm Proficiency Testing Study RAD-53, July 2003 ERA RAD-54 ERA's RadChemThA Proficiency Testing Study RAD-54, October 2003 ERA RAD-55 ERA's RadChemTN' Proficiency Testing Study RAD-55, January 2004 ERA RAD-57 ERA's RadChemTNM Proficiency Testing Study RAD-57, July 2004 ERA RAD-58 ERA's RadChemTM Proficiency Testing Study RAD-58, October 2004 GEL QAP 2005 GEL Quality Assurance Plan, Revision 18,-February 2005 GMP-QAPP 2004 Groundwater Monitoring Program Quality Assurance Project Plan, Revision 1, 2004 GMR 1999 Groundwater Monitoring Report, Malcolm Pirnie, September 1999 GW WPIR 2004 Groundwater Sample Collection Work Plan and Inspection Record, WP&IR # 24265-000-GEN-SITE-1011-000, May 2004 HIWP 2002 Phase II Hydrogeologic Investigation Work Plan, May 2002 LP 2002 Haddam Neck Plant -License Termination Plan (LTP), Rev. 2, August 2004 MAPEP-S6 Mixed Analyte Performance Evaluation Program -Soil Sample Participating Laboratory Report, 2/8/2000 MAPEP-S7 Mixed Analyte Performance Evaluation Program -Soil Sample Performance Report, 1/29/2001 MAPEP-S8 Mixed Analyte Performance Evaluation Program -Soil Sample Performance Report, 8/8/2002 MAPEP-S9 Mixed Analyte Performance Evaluation Program -Soil Sample Preliminary Report, 12/5/2002 MAPEP-S10 Mixed Analyte Performance Evaluation Program -Soil Sample Preliminary Report, 12/2003 MAPEP-W7 Mixed Analyte Performance Evaluation Program -Water Sample Performance Report, 7/6/2000 MAPEP-W8 Mixed Analyte Performance Evaluation Program -Water Sample Performance Report, 5/8/2002 MAPEP-W9 Mixed Analyte Performance Evaluation Program -Water Sample Performance Report, 2/11/2003 MAPEP-W10 Mixed Analyte Performance Evaluation Program -Water Sample Performance Report, February 2002 66 8 References MAPEP-W11 MAPEP-12 NSWPT 1998 RPM 5.3-0 RPM 5.3-1 RPM 5.3-2 RPM 5.3-3 SEP-0904 SEP-1204 QAP 52 QAP 53 QAP 54 QAP 55 QAP 56 QAP 57 QAP 58 QAP-59 QAP-60 Mixed Analyte Performance Evaluation Program -Water Sample Performance Report, May 2004 Mixed Analyte Performance Evaluation Program Study 12 -Soil, Water and Radiological Filter Sample Performance Report, November 2004 National Standards for Water Proficiency Testing Studies Criteria Document, USEPA December 30,1998 Groundwater Monitoring Program, Revision 0, September 2002 Groundwater Level Measurement and Sample Collection in Monitoring Wells, Revision CY-001, March 2004 Monitoring Well Drilling and Completion, June 2003 Groundwater Sampling Event Planning and Data Management, June 2003 Sample Event Plan for September 2004 Sample Event Plan for December 2004 Semi-Annual Report of the Department of Energy, Office of Environmental Management, Quality Assessment Program (EML-608), June 2000 Semi-Annual Report of the Department of Energy, Office of Environmental Management, Quality Assessment Program (EML-611), December 2000 Semi-Annual Report of the Department of Energy, Office of Environmental Management, Quality Assessment Program (EML-613), June 2001 Semi-Annual Report of the Department of Energy, Office of Environmental Management, Quality Assessment Program (EML-615), December 2001 Semi-Annual Report of the Department of Energy, Office of Environmental Management, Quality Assessment Program (EML-617), June 2002 Semi-Annual Report of the Department of Energy, Office of Environmental Management, Quality Assessment Program (EML-618), December 2002 Semi-Annual Report of the Department of Energy, Office of Environmental Management, Quality Assessment Program (EML-621), June 2004 Office of Environmental Management, Quality Assessment Program (QAP 59), December 2003 Office of Environmental Management, Quality Assessment Program (QAP 60), June 2004 67 9 Definitions C4 Concentration (Q) -The concentration level for a single analyte that will result in a 4-mrem per year total effective dose equivalent (TEDE) based on target organ dose methodology.

Contract Required Detection Limit (CRDL) -Analysis sensitivity requirements required by contract or SOW. Compliance is determined by comparison with sample specific MDCs or MDLs.False Negative Rate ([3, f3) -The rate at which the statistical procedure does not indicate possible contamination, when contamination is present at some level (P denotes one sample and one constituent, P* denotes multiple samples and one constituent).

False Positive Rate (a, a*) -The rate at which the statistical procedure indicates possible contamination, when contamination is not present (a denotes one sample and one constituent, a* denotes multiple samples and one constituent).

Freshet- A rapidly rising flood of minor severity and short duration, attributed to heavy rains or rapidly melting snow.Instrument Detection Limit (IDL) -The level at which a measurement can be differentiated from background with some degree of confidence.

Computed from the counting error associated with the instrument background or blank counting conditions usually expressed in terms of counts or count rate.Lab Control Sample (LCS) -A sample prepared by adding a known amount of target analyte to deionized distilled water. Used to assess the method accuracy and long-term analytical precision.

Lower Limit of Detection (LLD) -The level at which a measurement can be differentiated from background with some degree of confidence.

Computed from the counting error associated with the analytical blank counting conditions usually expressed in terms of counts or count rate.Matrix Spike (MS) -A sample prepared by adding a known amount of target analyte to a specified amount of matrix sample for which an independent estimate of the target analyte concentration is available.

Used to determine the effect of matrix on a method's recovery efficiency.

68 9 Definitions Matrix Spike Duplicate (MSD) -A known amount of target analyte added to two samples taken from and representative of the same population and carried through all steps of the analytical procedures in an identical manner. Used to assess variance of the sample analysis.Maximum Contaminant Level (MCL) -The average concentration level for a single analyte that will result in a 4-mrem per year total effective dose equivalent CEDE) based on target organ dose methodology.

Method Detection Limit (MDL) -The concentration of a substance that can be measured and reported at the 99% confidence level to be greater than zero.Minimum Detectable Activity (MDA) -Analogous to the LLD but includes conversion factors to relate background count rate to analyte activity.Minimum Detectable Concentration (MDC) -A level analogous to the LLD but includes conversion factors to relate background count rate to analyte concentration.

Relative Percent Difference (RPD) -A measure of the precision of two results, defined as the absolute difference divided by the average of the two results multiplied by 100.Required Detection Limit (RDL) -Analysis sensitivity requirements required by contract or SOW. Compliance is determined by comparison with sample specific MDCs or MDLs.Total Propagated Uncertainty (TPU) -Includes all factors that contribute to the overall uncertainty including counting statistics, sample mass, chemical yield and calibration factors.69 10 Acronyms CAP Corrective Action Program CRDL Contract required Detection Limit CSM Conceptual Site Model CYAPCo Connecticut Yankee Atomic Power Company DOE Department of Energy EOF Emergency Operations Facility EPA Environmental Protection Agency FDR Field Daily Reports GMP Groundwater Monitoring Program GPC Gas Proportional Counting GWMP Groundwater Monitoring Program HNP Haddam Neck Plant HTD Hard to Detect LCS Laboratory Control Sample LSC Liquid Scintillation Counting LTP License Termination Plan MAPEP Mixed Analyte Performance Evaluation Program MCL Maximum Contaminant Level MDC Minimum Detection Concentration MDL Minimum Detection Limit MS Matrix Spike MSL Mean Sea Level NCR Nonconformance Reporting NELAC The National Environmental Laboratory Accreditation Conference NSWPT National Standards for Water Proficiency Testing Studies Criteria NRC Nuclear Regulatory Commission 70 NTU Nephelometric Turbidity Unit PAB Primary Auxiliary Building pCi/L picocurie per liter QAP Quality Assurance Program QAPP Quality Assurance Project Plan QA/QC Quality Assurance/Quality Control RCB Reactor Containment Building RCRA Resource Conservation and Recovery Act RESL Radiological and Environmental Sciences Laboratory RPD Relative Percent Difference RSR Remediation Standard Regulation SOC Substance of Concern SOP Standard Operation Procedure TEDE Total Effective Dose Equivalent TPU Total Propagated Uncertainty WP&IR Work Plan and Inspection Record 71 Table 2-1: Summary of Monitoring WVell Information Top of Bottom of TOC Screen 1(2) Screen (2) Hydrostratigraphic Well ID Northing Easting Elevation (1) (ft bgs) (ft bgs) Unit Aquifer Well Status AST1 236310.83 668931.59 21.55 10 20 Unconsolidated unconfined l0917/2004(3)

AST2 236322.94 668948.16 19.99 5 15 Unconsolidated unconfined 09/17/2004(3)

AST3 236327.17 668909.46 21.2 5 15 Unconsolidated unconfined 09117/2004 (3 AST4 236341.1 668927.83 20.73 5 15 Unconsolidated unconfined 09117/2004 (3 EOF Supply-1 NSD NSD NSD 780 800 Deep Bedrock confined Active EOF Supply-2 NSD NSD NSD 1130 1150 Deep Bedrock confined Active MW-EOF-1 237503.96 667408.75 24.08 6 16 Unconsolidated unconfined Active MW-EOF-2 237513.48 667418.44 24.12 7 17 Unconsolidated unconfined Active MW1 235304.54 670604.26 12.21 28 38 Unconsolidated unconfined Active MW2 235677.79 670527.35 15.99 29 39 Unconsolidated unconfined Active MW3 235488.22 670555.25 10.75 12 22 Unconsolidated unconfined Active MW4 235638.02 670371.6 15.03 26.5 36.5 Unconsolidated unconfined Active MW5 NSD NSD NSD 73 93 Unconsolidated unconfined 07/07/2004 (3 MW6 NSD NSD NSD 58 108 Unconsolidated unconfined 07/07/2004 (3 MW7 NSD NSD NSD 38 58 Unconsolidated unconfined 07/07/2004 (3 MW8 NSD NSD NSD 58 88 Unconsolidated unconfined 07/07/2004 (3 MW9 NSD NSD NSD 66 116 Unconsolidated unconfined 07/06/2004 (3 MW10 NSD NSD NSD 48 98 Unconsolidated unconfined 07/07/2004 (3 MW1 1 NSD NSD NSD 56 66 Unconsolidated unconfined 07/07/2004 (3 MW12 NSD NSD NSD 57 97 Unconsolidated unconfined 07/06/2004 (3 MW13 235130.81 670766.81 20.04 66 96 Unconsolidated unconfined Active MW14 NSD NSD NSD 66 86 Unconsolidated unconfined 07I08/2004 (3 MW15 NSD NSD NSD 31 81 Unconsolidated unconfined 07/07/2004 (3 MW16D NSD NSD NSD 43 113 Unconsolidated unconfined 07/07/2004 (3 MW16S NSD NSD NSD 4.5 24.5 Unconsolidated unconfined 07/07/2004 (3 MW17 NSD NSD NSD 37 107 Unconsolidated unconfined 07/07/2004 (3 MW18 NSD NSD NSD 30 60 Unconsolidated unconfined 07/06/2004 (3 MW100D 236964.21 668415.29 16.45 21 31 Deep Bedrock confined Active MW100S 236959.88 668418.62 16.45 3.5 9 Unconsolidated unconfined Active MW101D 236845.02 668655.36 20.82 39.8 49.8 Deep Bedrock confined Active MW101S 236842.33 668653.7 20.62 8 18 Bedrock unconfined Active MW102D 236651.79 668905.29 20.66 43 53 Deep Bedrock confined Active MW102S 236655.03 668907.67 20.53 12.8 22.5 Bedrock unconfined Active MW103D 236672.34 668730.02 21.05 45 55 Deep Bedrock confined Active MW103S 236671.52 668726.05 20.94 15.5 24.5 Bedrock unconfined Active MW104S 236673.17 668493.3 20.1 13 23 Shallow Bedrock Perched Active MW105D 236534.06 668645.74 20.66 45.5 55.5 Deep Bedrock confined 08/12/2004 (3 MW105S 236536.03 668642.86 20.66 14.5 24.5 Unconsolidated unconfined 08/12/2004 (4 MW106D 236464.64 668730.32 20.7 45 55 Deep Bedrock confined Active MW106S 236473.85 668738.1 20.56 14.5 24.5 Shallow Bedrock unconfined Active MW107D 236374.52 668874.54 20.52 90 100 Shallow Bedrock confined Active 72 Table 2-1 Summary of Monitorin Wcll Information (continued)

Top of Bottom of TOC Screen (2) Screen (2) Hydrostratigraphic Well ID Northing Easting Elevation (I) (ft bgs) (ft bgs) Unit Aquifer Well Status MW107S 236371.27 668871.82 20.39 15 25 Unconsolidated unconfined Active MW108 236243.62 669142.69 12.15 15 25 Unconsolidated unconfined Active MW109D 236327.48 668450.18 20.54 45 55 Bedrock confined Active MW109S 236329.11 668448.13 20.64 15 25 Unconsolidated unconfined Active MW11OD 236083.96 668812.01 22.83 70 80 Bedrock confined Active MW1IOS 236081.77 668815.38 22.47 15 25 Unconsolidated unconfined Active MW11iS 235931.47 668940.43 18.21 15 25 Unconsolidated unconfined O9/17/2004(3)

MW112S 235797.44 669204.17 14.51 15 25 Unconsolidated unconfined Active MWI113S 235773.51 669398.06 13.56 15 25 Unconsolidated unconfined Active MW114S 236615.5 668820.92 20.76 7.5 17.5 Unconsolidated unconfined Active MW115S 236603.1 668837 20.81 7 17 Unconsolidated unconfined Active MW1I7S 235070.57 671286.68 15.95 15 25 Unconsolidated unconfined Active MW122D 236490.49 668988.55 19.99 184.7 194.7 Deep Bedrock confined Active MW122S 236486.5 668988.86 19.84 9 19 Unconsolidated unconfined Active MW123 236629.95 668473.66 20.19 23.5 33.47 Shallow Bedrock confined Active MW124 236478.85 668448.53 20.81 11 21 Unconsolidated unconfined Active MW125 236324.23 668797.83 20.31 11 22 Unconsolidated unconfined Active MW200 236230.82 673217.72 54.68 8 18 Unconsolidated unconfined Active MW201 235811.2 673214.61 58.74 25 35 Unconsolidated unconfined Active MW202 236176.51 672987.49 51.64 10 20 Unconsolidated unconfined Active MW203 236099.24 672994.67 46.21 8 18 Unconsolidated unconfined Active MW204 235928.48 673033.93 41.88 5 15 Unconsolidated unconfined Active MW205 235826.44 673093.28 40.57 5 15 Unconsolidated unconfined Active MW206 235789.83 673016.63 43.1 5 15 Unconsolidated unconfined Active MW207 236021.6 673148.93 46.99 15 25 Unconsolidated unconfined Active MW208 235742.54 673120.08 50.21 12 32 Unconsolidated unconfined Active MW502 236770.63 668013.02 17.9 20.54 30.22 Unconsolidated unconfined Active MW503 236928.27 667916.8 15.31 25.14 34.83 Unconsolidated unconfined Active MW504 236881.63 668116.16 16.66 18.97 28.67 Unconsolidated unconfined Active MW505 237062.99 668090.6 14.98 16.37 25.07 Deep Bedrock Perched Active MW507D 236799.08 668299.65 18.56 67 77 Deep Bedrock confined Active MW507S 236795.86 668303.57 18.46 10.88 20.88 Unconsolidated Perched Active MW508D 236663.18 668190.54 17.78 81.5 91.5 Shallow Bedrock confined Active MW508S 236666.79 668193.26 17.63 14 24 Unconsolidated Perched Active TPW1 NSD NSD 9.5 80 100 Unconsolidated unconfined Active TPW2 NSD NSD 9.5 80 110 Unconsolidated unconfined Active TWi 235020.46 670967.37 17.73 94 112 Unconsolidated unconfined Active TW2 235292.04 670515.44 9.67 101 104 Unconsolidated unconfined Active TW3 235285.23 670802.16 13.02 49 89 Unconsolidated unconfined Active TW4 235087.35 671193.58 10.71 80 120 Unconsolidated unconfined Active Well-A NSD NSD NSD 37 47 Unconsolidated unconfined Active Well-B NSD NSD NSD 45 57 Unconsolidated unconfined Active 10-2 NSD NSD 10.2 58 63 Unconsolidated unconfined Active 8-2 NSD NSD NSD 40 47 Unconsolidated unconfined Active 9-2 NSD NSD NSD 50 57 Unconsolidated unconfined Active Notes: (1) Top of Casing elevations from Kratzert, Jones and Associates, Bold values are based on Malcolm Pirnie data._~,/ (2) Screen depths, in feet below ground surface, are based on construction logs.(3) Well abandoned on this date (4) Well was converted to DW-105 on this date.NSD= No Survey data available 73 Table 2-2: Selected Events in Operation of the Water Level Monitoring System-Third and Fourth Quarter 2004 -Event Date Comment Packer testing July Flute rcmoval July through August Dcep bedrock borehole July through August Response to testing observed in confined hydrophysical testing aquifer monitoring wells MW-106D, MW-107D, MW-109D, MW-1 OD and MW-122D.Mat Sump offlinc August 11 -12 Aquifcr test September 15 -18 Step draw-down and pumping Selected transducers changed and September 14 -27 Recording water level at I minute, and I downloaded for aquifer test sec intervals for selected transducers Mat sump offline September 19- 22 Offline due to power outage 3rd quarter sampling September 20- October 10 Batteries and clastomers changed, November through December IOID replaced and sent back to ransducers downloaded manufacture for repairs. 106D and IIOS sent back to manufacture for repairs Mat sump offline November 10 -12 Pumping begins in RHR pit November 18 Response seen in MW-I01D, MW-102D, MW-103D and MW-106D Batteries fail in river transducer November 21 Premature battery failure due to cold weather. Missing data were approximated using TW-1 as a surrogate.

ransduccr download December MW-102 S/D, 104, 106 S/D, I1OS, 123, 124, and 122 could not be downloaded due o hardware and access problems th quarter sampling December 7 -16 Mat sump offline December 23 -26 Table 2-3: Groundwater Elevation Conditions Observed in the Perched Aquifer-Third and Fourth Quarter 2004 -General Water Elevation Responsive Exhibits Responsive Well ID Conditions to Local Tidal to Dewatering Precipitation?

Response?

Activities?

MW508S Generally steady at approx. 10 Oft Yes No No I____ Mean Sea Level (MSL) I I MW104S Varied with general incline from +7 Yes No No I I ~ft MSL to +8 feet MSL III Table 2-4: Groundwvater Elevation Conditions Observed in the Unconfined Aquifer-Third and Fourth Quarter 2004 -Responsive to Exhibits Tidal Responsive to Well ID General Water Elevation Conditions L Responscl Dewatering Precipitation?

Response?

Activities?

General incline from MW100S +12 ft MSLto +1 ftMSL Yes No No MW102S Variable with general incline from Yes No No+1 It MSL to +16 MSL MW102S Variable with general incline from Yes No No+5 It MSL to -'-l ft MSL Variable with general incline from +3 ft MW103S MSL to +6 ft MSL, then a decline to -2 ft Yes No Yes MSI at the onset of dewatering MW105S Abandoned on 8/12/04- 3rd Qtr MW106S Variable with general decline from Yes No Yes+3 ft MSL to +4 ft MSL MW107S Varied with general decline from Yes Yes No+7 ft MSL to +4 ft MSL YesYesNo MW108 Varied with general incline from Yes Yes No+3 ft MSL to +4 ft MSL MW1 22S Varied with general incline from Yes Yes No+2 ft MSL to +4 ft MSL MW1 3 Varied, but generally steady Yes Yes No at approx. +1 ft MSL MW1i3S Varied with general incline from Yes Yes No+2 It MSL to +4 ft MSL ______MWI 14S Dry from dewatering activities Yes No Yes MW122S Varied with general decline from Yes Yes No+5 ft MSL to +3 ft MSL MW124 Varied with general decline from No Yes No+3 ft MSL to +1 ft MSL MW504S Varied with general incline from Yes No No+3 ft MSL to +4.5 ft MSL__ _ _ _ _ __ _ _ _ _ _ _ _T Varied, but generally steady Yes Yes No at approx. +2.5 ft MSL River Varied, but generally steady Yes Yes No___________at approx. +1 ft MSL 75 Table 2-5: Groundwater Elevation Conditions Observed in the Confined Aquifer-Third and Fourth Quarter 2004 -General Water Elevation Responsive to Exhibits Tidal Responsive to Well ID CodtosLocal Rsoe? Dewatering Conditions Precipitation?

Response?

Activities?

MW101D Transducer exhibiting data shifts Yes No Yes MW102D Variable wfith general decline Yes No Yes from +4 ft MSL to +1 ft MSL MW103D Variable with general decline Yes No Yes from +3 ft MSL to -8 ft MSL MW105D abandoned on 8/12/04- 3rd Qtr MW106D Variable with general decline YsN e from +3 ft MSL to -2.5 ft MSL Yes No Yes MW1O7D Variable with general incline Yes -also MW0Dfrom +3 ft MSL to +4 ft MSL responds to river Yes No change MW109D Variable, but generally steady Responds to river Yes No at approx +3 ft MSL change MW110D Variable with general incline Responds to river Yes No from +1 ft MSL to +2 ft MSL change MW508D Variable with general incline Responds to river Yes No from +3 ft MSL to +4 ft ML change MW122D Variable with general incline Yes Yes No from +2.5 ft MSL to +3.5 ft ML MW123 Varied, but generally steady at Yes No insufficient data_____________

aprrox. +4.5 ft MSL 76 Table 2-6: Static Water Levels in Monitoring Wells-Third and Fourth Quarter 2004 -3rd Quarter 4th Quarter Aquifer Groundwater Groundwater Monitoring Elevations 1 2 1 Elevation('

2 1 Well Screened 8122/04 12/1/04 in Well Name TOC Elevation at 11:15 at 23:55 (U, C, P)Industrial Area MW101D 20.86 ND ND C MW102D 20.65 2.50 0.29 C MW103D 21.06 2.01 -5.18 C MW106D 20.69 2.10 -0.70 C MW107D 20.54 1.89 1.23 C MW109D 20.56 3.16 3.22 C MW110D 22.86 0.75 1.51 C MW122D 20.00 1.82 2.24 C MW508D 17.79 3.05 3.26 C Mat Sump 21.72 -19.87 -18.95 U/C MW104S 20.11 13.50 11.05 P MW508S 17.81 10.36 9.80 P MW100S 16.47 14.32 15.61 U MW101S 20.66 14.91 15.86 U MW1 02S 20.57 6.30 9.91 U MW103S 20.94 3.18 -1.78 U MW1 06S 20.57 5.66 1.45 U MW107S 20.44 2.74 2.33 U MW108 12.30 2.45 3.59 U MW109S 20.65 2.35 3.63 U MW11 S 22.48 1.69 ND U MW113S 13.60 2.53 3.95 U MW114S 20.78 DRY DRY U MW123 20.19 ND ND U MW122S 19.84 2.81 ND U MW124 20.82 2.87 ND U MW504S 16.67 3.24 4.05 U RIVER 7.90 -0.27 ND U NOTES: 1: Static water level date & time from transducers used to complete groundwater contour intervals 2: The date chosen for the contour maps preceded the groundwater sampling event to ensure that there had not been draw-down in any of the wells.TOC: Top-of-Casing ND: No data U: Unconfined C: Confined P: Perched 77 Table 2-6 Static Water Levels in Monitoring AVONls-Third and Fourth Quarter 2004 (continued)

-3rd Quarter 4th Quarter Aquifer Groundwater Groundwater Monitoring Elevation

" 2 1 Elevation" 2) Well Screened 8/22104 12/1/04 in Well Name TOC Elevation at 11:15 at 23:55 (U, C, P)TW-1 17.73 0.42 2.02 U Mat Sump 21.72 -19.87 -18.95 U/C Landfill Area MW200 54.68 not installed 36.64 U MW202 51.64 not installed 37.12 U MW203 46.21 not installed 36.45 U MW204 41.88 not installed 35.01 U MW205 40.57 not installed 33.23 U MW206 43.1 not installed 34.59 U MW207 46.99 not installed 33.59 U MW208 50.21 not installed 26.98 U NOTES: 1: Static water levels from transducers used to complete groundwater contour intervals 2: The date chosen for the contour maps preceded the groundwater sampling event to ensure that there had not been draw-down in any of the wells.TOC: Top-of-Casing ND: No data U: Unconfined C: Confined P: Perched 78 Table 3-1: Summary of Field Parameters for Third Quarter 2004 Static Specific Water Turbidity DO Conductance Well ID Level DTW (ft) (NTU) (mglL) Eh (mv) pH (mslcm) Temp ©EOF2 12.28 12.69 2.4 0 158 6.91 0.524 17.1 MW1 12.39 11.71 8.4 0.01 -144 7.12 0.19 13.55 MW2 13.98 13.89 6.3 0.55 2.09 6.49 0.264 13.91 MW3 8.08 9.76 39 4.63 -26 6.55 0.097 13.25 MW100S 2.51 4.83 2.51 0 139 6.64 0.162 16.9 MW100D 2.96 9.75 4.06 0 22 6.36 0.73 13.2 MW101S 5.93 6.07 3 7.85 166 6.94 0.16 19.93 MW101D 17.33 17.55 1.92 8.77 189 7.77 163 14.72 MW102S 16.5 16.7 2 8.44 216 5.96 129 16.24 MW102D 18.22 33.12 6.72 6.07 168 7.53 0.335 17.48 MW103S 17.12 17.17 4 1.66 6 9.8 317 13.77 MW103D 18.72 39.5 4.12 6.5 258 5.86 0.91 16.77 MW104S 9.57 10.11 3.6 9.61 216 6.44 0.356 17.18 MW106S 18.18 18.57 3.9 0.43 94 6.21 3.68 16.78 MW106D 18.07 20.62 3.55 1.66 77 8.66 0.346 17.74 MW107S 17.37 17.6 3.18 0 78 5.77 0.52 17.4 MW107D 17.87 19.28 6.4 1.19 88 6.52 0.16 17.65 MW108S 8.78 8.81 2.06 0 -68 6.27 0.129 16.4 MW109S 17.99 17.98 11.6 3.42 91 6.41 0.737 15.35 MW109D 17 18.48 38 2.88 -10 7.7 0.425 15.7 MW110S 20.38 20.58 4.04 1.95 262 6.18 0.298 14.58 MW110D 20.5 21.08 6.98 0.38 31 7.71 0.291 14.66 MW112S 12.38 12.4 2.9 3.24 282 5.27 0.072 14.11 MW113S 11.29 11.33 2.7 2.16 247 5.75 0.393 16.42 MW117S 11.76 11.95 15 2.34 -88 6.42 0.523 13.24 MW122S 16.72 10.23 3 0 -57 5.87 182 17.03 MW122D 17.73 19.07 7.95 0 -242 9.43 0.135 15.15 MW123 14.55 15.13 4.89 8.28 1.99 6.63 0.893 16.38 MW124 17.71 17.78 3.78 4.96 181 6.71 0.32 14.85 MW125S 17.35 17.52 2.7 0 54 6.63 0.475 20.5 MW502 14.65 14.67 2.51 0 -132 6.58 0.449 14.4 MW503 12.18 12.23 2.3 0 -167 5.99 0.158 13.6 MW504 13.36 13.38 1.9 0 -91 6.39 0.337 20.5 MW505 4.42 4.42 2.02 0 -166 7.2 0.46 14.5 MW507D 13 14.77 7.89 0.82 -62 7.65 0.133 17.41 MW507S 7.7 7.81 16.8 0.46 -93 6.89 0.303 21.68 MW508S 7.32 7.5 32.8 0.76 -30 6.55 0.326 20.21 MW508D 14.13 14.91 10.24 2.73 30 8.06 0.168 17.17 NOTES NM: No measurements were taken for this parameter NS: Well was not sampled during this event due to low water level Well was sampled with a bailer 79 Table 3-2: Summary of Field Parameters for Fourth Quarter 2004 Well ID ATW1 CMS EOF2 MW1 MW2 MW3 MW4 MW1 00D MW100S MW1 01D MW101S MW102D MW1 02S MW103D MW103S MW104S MW106D MW106S MW107D MW107S MW108S MWI09D MW109S MW11OD MW110S MW112S MW113S MW117S MW122D MW122S MW123 MW124S MW125S MW200 MW202 MW203 MW204 MW205 MW206 MW207 NOTES Static Water Level 16.18 8.33 8.55 13.18 8.98 11.53 1.35 1.05 24.45 4.88 19.3 10.09 23 10.73 10.73 21.42 20.97 18.69 17.44 8.15 16.85 16.94 20.36 20.19 12.32 11.41 9.67 18.1 17.55 15.21 16.82 17.55 18.04 14.52 9.76 6.87 7.34 8.51 13.4 Turbidity DTW (ft) (NTU)16.18 2.28 14 8.51 0.75 9.14 3.9 13.36 4.1 9.3 4.02 11.69 2.9 8.52 0.13 2.38 1.12 24.55 3.3 4.95 2.5 19.28 12 10.14 2.3 N/A 16 11.19 0.23 11.19 0.23 22.28 2.2 22.22 7.8 20.29 2.54 17.59 2.93 8.21 2.56 18.45 2.1 16.98 3.26 20.99 5.04 20.41 1.12 12.44 3.04 11.49 4.99 9.79 1.81 19.22 13 18.1 7.3**15.43 1.4 16.82 0.71 17.79 4.01 18.3 9 14.63 <1 10.25 2.3 7.23 2.23 7.87 3.5 8.81 3 13.44 0.21 DO (mglL)0 5.8 6.03 0.28 0 0 0 0 4.55 2 9.7 4 10 5.3 10.1 10.1 0.6 4.1 2.29 0 0.12 2.32 0.91 1.97 5.16 4.12 0.85 0 1.1<.01 7.2 0.4 5.2 7.5 5.9 1.11 1.2 3.29 0 6.15 Eh (mv)125 80 154-113 161-2 335 35 139 150 130 220 140 290 204 204 90 160 216 92-39 181 99 126 262 303 278 0.77-40-50 180 138 1.69 400 320 183 165 165 50 162 pH 5.31 5.6 7 6.83 6.43 6.32 5.71 5.89 6.58 8.1 7.1 8.1 6.8 7.1 6.66 6.66 8.8 6.4 6.14 5.56 0.19 7.25 5.98 6.94 5.91 5.37 5.44 6.33 9.4 6.6 6.5 6.27 6.47 4.9 5.1 5.8 5.56 5.66 5.4 5.89 Specific Conductance (ms/cm)1.52 0..81 1.61 0.209 243 0.106 0.127 0.086 0.272 167 88 245 124 336 0.270 0.270 300 2240 0.026 1.02 0.157 0.365 1.13 0.202 0.222 0.067 0.96 1.13 72 726 652 1.02 1.11 0.069 0.064 0.101 0.08 0.079 0.097 0.089 Temp 14.1 14.2 13.54 11.57 11.91 10.71 11.99 12.36 10.75 11 10 8.3 11 11 12.5 12.5 14 15 9.23 15 14.23 8.44 12.7 13.9 13.45 11.8 13.33 12.05 13 12 13 13.01 8.93 11.9 10.8 11.62 10.73 11.92 11.9 10.6 NM: No measurements were taken for this parameter NS: Well was not sampled during this event due to low water level Well was sampled with a bailer 80 Table 3-2: Summary of Field Parameters for Fourth Quarter 2004 (continued)

Well ID MW208 MW502S MW503 MW504 MW505 MW507D MW507S MW508D MW508S SWB EP165 EP166 EP171 NOTES NM: NS: Static Water Level 23.23 13.62 10.92 12.4 3.66 12.35 6.93 13.57 6.48 N/A N/A N/A N/A DTW (ft)23.5 13.67 10.96 12.4 3.67 14.38 7.09 14.2 6.79 N/A N/A N/A N/A Turbidity (NTU)6 9 3.61 0.55 1.9 0.8 3.49 2.36 4.51 1.92 2 1.1 2.2 DO (mg/L)6.4 0 0 0 0 0 0 0 0 9.73 13 13 12 Eh (mv)300-135-188-197-222-19-195-105-132 138 200 57 140 pH 5.16 6.76 5.98 6.28 6.79 7.19 6.58 8 6.15 5.34 6.9 7.8 7.3 Specific Conductance (ms/cm)0.086 0.92 0.163 0.92 0.479 0.148 0.421 0.192 1.11 0.165 166 237 187 Temp i 10.5 11.98 12.85 13.64 11.41 13.38 14.56 14.53 15.09 19.52 N/A N/A N/A No measurements were taken for this parameter Well wvas not sampled during this event due to low water level Well wvas sampled with a bailer 81 (Table 3-3: Sample Locations and Analyses Requested (Third Quarter 2004)C Number Location Boron Gross a/I y-Isotopic H-3 Sr-90 HTD Geochem Total U Isotopic U EOF-2 EOF Area X X X X X MW100D Industrial Area X X X X X X X MW100S Industrial Area X X X X X X MW101D Industrial Area X X X X X X X X MW1O1S Industrial Area X X X X X X X MW102D Industrial Area X X X X X X X X MW102S Industrial Area X X X X X X X MW103D Industrial Area X X X X X X X X X MW103S Industrial Area X X X X X X X X X MW104S Industrial Area X X X X X X X X DW105 Industrial Area X X X X X X X X MW106D Industrial Area X X X X X X X X X MW106S Industrial Area X X X X X X X X MW107D Industrial Area X X X X X X X MW107S Industrial Area X X X X X X X MW108S Industrial Area X X X X X X X MW109D Industrial Area X X X X X X X X MW109S Industrial Area X X X X X X X MW110D Industrial Area X X X X X X X X MW110S Industrial Area X X X X X X X MW112S Peninsula X X X X X MW1I13S Peninsula X X X X X MW114S Industrial Area X X X X X MW115S Industrial Area X X X X X MW117S Peninsula X X X X X Notes: HTD: y-lsotopic:

Geochem: Isotopic U: C-14, Fe-55, Ni-63, Tc-99, Pu a (Pu-238, Pu-239,240), Pu-241 Am/Cm a (Am-241, Cm-242, Cm-243,244)

Mn-54, Co-60, Nb-94, Ag-108m, Cs-134, Cs-137, Eu-152, Eu-154, Eu-155, Am-241 Anions (CaO 3 2', HC03-, S04 ", Cl'), Cations (Ca+z, Mg"z, Na+, K+)U-234, U-235, U-238, U-235/Total U ratio 82 (Table 3-3: Samplc Locations and Analyses Requested (Third Quarter 2004)-continued

-(Number Location Boron Gross a/, y-lsotopic H-3 Sr-90 HTD Geochem Total U Isotopic U MW122D Industrial Area X X X X X X X MW122S Industrial Area X X X X X X X MW600 (MW122S Industrial Area X X X X X X X dup)MW123S Industrial Area X X X X X MW124S Industrial Area X X X X X MW125S Industrial Area X X X X X MW502 Parking Lot X X X X MW503 Parking Lot X X X X MW504 Parking Lot X X X X MW505 Parking Lot X X X X MW507D Parking Lot X X X X MW507S Parking Lot X X X X MW508D Parking Lot X X X X MW508S Parking Lot X X X X MW601 Industrial Area X X X X X (RB)MWi Peninsula X X X X MW2 Peninsula X X X X MW3 Peninsula X X X X Notes: HITD: y-lsotopic:

Geochem: Isotopic U: C-14, Fe-55, Ni-63, Tc-99, Pu a (Pu-238, Pu-239,240), Pu-241 Am/Cm a (Am-241, Cm-242, Cm-243,244)

Mn-54, Co-60, Nb-94, Ag-108m, Cs-134, Cs-137, Eu-152, Eu-154, Eu-155, Am-241 Anions (CaO3 z, HICO3-, S04', C1-), Cations (Ca+z, Mg*', Na+, K+)U-234, U-235, U-238, U-235/Total U ratio 83 (Table 3-4: Sample Locations and Analyses Requested (Fourth Quarter 2004)(Well Location Boron Gross AIB Gamma H-3 Sr-90 HTD Geochem Total U Isotopic U Number: L ctoBoo Gr s NB Isotopic ATW1 Industrial Area X X X X X X X CMS1 Industrial Area X X X X X X X EP165 Industrial Area X X X X X X X EP166 Industrial Area X X X X X X X EP171 Industrial Area X X X X X X X DW1 Industrial Area X X X X X X X DW3 Industrial Area X X X X X X X DW4 Industrial Area X X X X X X X DW5 Industrial Area X X X X X X X EOF2 Industrial Area X X X X X MWI Peninsula X X X X X MW2 Peninsula X X X X X MW3 Peninsula X X X X X MW4 Peninsula X X X X X MW100D Industrial Area X X X X X MW100S Industrial Area X X X X X MW101D Industrial Area X X X X X X MW101S Industrial Area X X X X X X MW102D Industrial Area X X X X X X MWI02S Industrial Area X X X X X X MW103D Industrial Area X X X X X X X MWI03S Industrial Area X X X X X X X MW600 Industrial Area X X X X X X X MW104S Industrial Area X X X X X X X Notes: HTD: y-lsotopic:

Geochem: Isotopic U: C-14, Fe-55, Ni-63, Tc-99, Pu a (Pu-238, Pu-239,240), Pu-241 Am/Cm a (Am-241, Cm-242, Cm-243,244)

Mn-54, Co-60, Nb-94, Ag-108m, Cs-134, Cs-137, Eu-152, Eu-154, Eu-155, Am-241 Anions (Ca0 3,. HCO3, S04", Cl'), Cations (Ca+z, Mg+z, Na+, K+)U-234, U-235, U-238, U-235/Total U ratio 84 (Table 3-4: Sample Locations and Analyses Requested (Fourth Quarter 2004)-continued

-(Werl Location Boron Gross A/B IGsaotmopmic H-3 Sr-90 HTD Geochem Total U Isotopic U MW106D Industrial Area X X X X X X X MW106S Industrial Area X X X X X X X MW107D Industrial Area X X X X X X MW107S Industrial Area X X X X X X MW108S Industrial Area X X X X X X MW109D Industrial Area X X X X X X MW109S Industrial Area X X X X X X MW110D Industrial Area X X X X X X MW11OS Industrial Area X X X X X X MW112S Peninsula X X X X X MW113S Peninsula X X X X X MW114S Industrial Area X X X X X X MWI15S Industrial Area X X X X X X MW117S Peninsula X X X X X MW122D Industrial Area X X X X X X MW122S Industrial Area X X X X X X MW123S Industrial Area X X X X X MW124S Industrial Area X X X X X MW125S Industrial Area X X X X X MW200 Landfill Area X X X X X X X MW201 Landfill Area X X X X X X X MW202 Landfill Area X X X X X X X MW203 Landfill Area X X X X X X X MW204 Landfill Area X X X X X X X MW205 Landfill Area X X X X X X X MW206 Landfill Area X X X X X X X MW207 Landfill Area X X X X X X X MW208 Landfill Area X X X X X X X Notes: HTD: y-Isotopic:

Geochem: Isotopic U: C-14, Fe-55, Ni-63, Tc-99, Pu a (Pu-238, Pu-239,240), Pu-241 Am/Cm a (Am-241, Cm-242, Cm-243,244)

Mn-54, Co-60, Nb-94, Ag-108m, Cs-134, Cs-137, Eu-152, Eu-154, Eu-155, Am-241 Anions (CaO 3 7', HC0 3 , S04", Cl), Cations (Ca"z, Mg+z, Na', K+)U-234, U-235, U-238, U-235ITotal U ratio 85 (Table 3-4: Sample Locations and Analyses Requested (Fourth Quarter 2004)-continued

-(Number: Location Boron Gross A/B Gamma H-3 Sr-90 HTD Geochem Total U Isotopic U MW502 Parking Lot X X X X MW503 Parking Lot X X X X MW504 Parking Lot X X X X MW505 Parking Lot X X X X MW507D Parking Lot X X X X MW507S Parking Lot X X X X MW508D Parking Lot X X X X MW508S Parking Lot X X X X X MW601 (RB) Industrial Area X X X X X SWA Peninsula X X X X X SWB Peninsula X X X X X Notes: IITD: y-lsotopic:

Geochem: Isotopic U: C-14, Fe-55, Ni-63, Tc-99, Pu a (Pu-238, Pu-239,240), Pu-241 Am/Cm a (Am-241, Cm-242, Cm-243,244)

Mn-54, Co-60, Nb-94, Ag-108m, Cs-134, Cs-137, Eu-152, Eu-154, Eu-155, Am-241 Anions (CaO 3-z, HC03-, S04-j, CE-), Cations (Ca+z, Mg", Na, K+)U-234, U-235, U-238, U-235/Total U ratio 86 (Table 4-1: Boron Concentrations (jtg/L) in Groundwater (Well ID Jun-00 Jun-01 Dec-01 Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sep-04 Dec-04 IOOD 10.8 <200 <50 68 <250 <50 <50 <27 <10 <27 6.3 19.9 10.4 25.4 13.7 100S NS <200 <50 710 <250 188 84.9 123 1,145 428 140 212 25.3 151 143 101)D 38.1 25.4 <50 <50 <250 NS <50 83.5 47 42.3 30 49.4 54 55.7 56.4 101S 53.8 34.4 77 <50 <250 NS <50 NS 43 235 47 49 68.6 144 24.9 102D 87.5 80. 1 290 96.4 <250 NS 428 64.2 392 110 98 113 97.1 124 135 102S 63.4 80.8 220 64.3 <250 NS <50 49 19 117 49 60.8 91.2 174 47 103D 63.6 57.9 88 165 <250 NS 69.5 105 76 58 48 90.9 57.1 70.3 57.4 103S 150.0 111 260 55.4 <250 NS 118 96.2 92 184 33 85.7 165 324 NS 104S NS 54.2 82 74 70.2 81.8 75.6 76.4 110 143 200 299 274 268 172 105D 51. 7 34.7 64 <50 <250 NS 58.5 60.4 41 67.1 59 67.5 60.8 NS NS 105S 2,940 1,760 2,400 1,340 <250 NS 945 915 618 1,200 540 735 484 NS NS 106D 52.2 40.4 <50 <50 <250 NS 69.4 51.3 51 51.7 59 74.3 64.7 85.7 124 106S NS 960 720 468 <250 NS 222 348 239 786 530 670 490 581 802 107D 30.9 18.4 <50 <50 <250 <50 <50 <27 173 <30 21 38 32.1 32.5 16.7 107S 91. 0 169 180 160 <250 <50 102 105 66 278 120 192 177 99.7 189 108S NS 82.9 120 100 <250 NS NS NS NS NS NS NS 68.3 161 180 109D 401.0 157 200 150 <250 NS 59.4 183 26 NS NS 210 191 184 176 109S 107.0 112 170 54 <250 510 179 76.8 126 203 190 254 124 130 98.6 1 OD 234.0 289 320 250 <250 265 203 93.3 127 334 170 179 236 408 102 1iOS 131.0 90.7 81 100 <250 97.3 179 320 162 206 180 238 291 284 281 IS 60.9 45.8 <50 52 <250 NS 61.5 37.2 52 58.1 NS NS 55.5 NS NS 112S NS 23.9 61 <50 <50 NS NS NS NS NS NS NS 47.8 77.1 74.5 113S NS 136 180 100 89.8 NS NS NS NS NS NS NS 110 130 106 114S 265.0 240 NS 134 201 NS 127 NS 90 203 140 173 1260 NS NS 115S 94.2 80.7 NS 175 149 NS 178 90.4 78 NS 100 195 NS NS NS 117S NS 17.8 57 75 59.7 NS NS NS NS NS NS NS 68.5 71.8 78.7 122D NI NI NI NI NI NI NI 178 179 178 180 224 223 264 92.2 NOTES NI: Well was not installed during sample event.NS: Well was not sampled during sample event.ND: Well was sampled but data is not available.

<50: Observed boron concentration was less than the Method Detection Limit (MDL)87 (Table 4-1: Boron Concentrations

([tg/liter) in Groundwater (continued)

(Well ID Jun-00 Jun-01 Dec-01 Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sep-04 Dec-04 122S NI NI NI NI NI NI NI 237 219 178 330 317 307 220 184 123S NI NI NI NI NI NI NI 64.6 46 67.8 88 107 90.8 134 113 124S NI NI NI NI NI NI NI 351 299 312 300 228 225 244 258 125S NI NI NI NI NI NI NI 426 365 489 360 390 445 531 308 ASTI 36.0 17.1 <50 <50 NS NS NS NS NS NS NS NS NS NS NS MAT 177.0 NS NS NS 128 NS NS NS NS NS NS NS NS NS III SU M P_ _ _ _ _ __ _ __ _ _ _ _ _ _ _ _EOF 2 NS 46.2 65 70 72.3 NS NS NS NS NS NS NS 63.4 65.5 85.6 TWI NS <200 <50 <50 NS NS NS NS NS NS NS NS NS NS NS MW13 NS 13.1 <50 <50 NS NS NS NS NS NS NS NS NS NS NS MWI NS NS NS NS NS NS NS NS NS NS NS NS 5.08 5.2 8.85 MW2 NS NS NS NS NS NS NS NS NS NS NS NS 15.5 18 19.5 MW3 NS NS NS NS NS NS NS NS NS NS NS NS 5.67 7.95 6.9 MW502 NS NS NS NS NS NS NS NS NS NS NS NS 65.2 63.1 73.1 MW503 NS NS NS NS NS NS NS NS NS NS NS NS 10.7 11.8 13.1 MW504 NS NS NS NS NS NS NS NS NS NS NS NS 42.7 49.6 50.6 MW505 NS NS NS NS NS NS NS NS NS NS NS NS 54.4 59.9 80 MW507D NS NS NS NS NS NS NS NS NS NS NS NS 36.7 35.4 34.4 MW507S NS NS NS NS NS NS NS NS NS NS NS NS 52.8 58.8 57.1 MW508D NS NS NS NS NS NS NS NS NS NS NS NS 66.1 59.1 58.9 MW508S NS NS NS NS NS NS NS NS NS NS NS NS 41.9 64.1 61.5 NOTES NI: Well was not installed during sample event.NS: Well was not sampled during sample event.ND: Well was sampled but data is not available.

<50: Observed boron concentration was less than the Method Detection Limit (MDL)88 Table 4-2: Gross a, P, Sr-90 and Cs-137 Concentrations (pCi/L) in Groundwater Sample Gross Well ID Event Alpha Gross Beta Sr-90 Cs-137 MW100D 2002 Q1 '- <5.01 MW100D 2002 Q2 ---<2.89 MW100D 2002 Q3 <0.83 3.59 -<3.22 MW100D 2002 Q4 <0.875 2.37 -<3.46 MW100D 2003 Q1 <0.672 3.02 -<4.09 MW100D 2003 Q2 2.00 6.60 -<5.9 MW100D 2003 03 <0.916 <2.68 -<4.22 MW100D 2003 Q4 0.78 2.58 -<7.76 MW100D 2004Q1 <0.952 1.31 -<3.59 MW100D 2004 Q2 2.38 <2.29 -<4.32 MW100D 2004 Q3 13.90 13.60 -<2.01 MW100D 2004Q4 <1.32 2.70 -<5.79 MW100S 2002Q1 ---3.21 MW100S 200202 --<2.18 MW100S 2002 03 0.60 5.72 -<3.59 MW100S 2002Q4 < 4.02 19.30 -<3.18 MW100S 2003Q1 <1.24 8.73 -<4.65 MW100S 2003 Q2 <1.8 4.76 -<6.5 MW100S 2003Q3 <0.914 4.00 -<4.18 MW100S 2003Q4 <1.41 6.52 -<7.48 MW100S 2004Q1 <2.8 4.23 -<3.13 MW100S 2004 Q2 <2.27 1.51 -<2.21 MW100S 2004 Q3 <1.24 2.46 -<2.19 MW100S 2004 Q4 <1.73 1.37 -<4.75 MW101D 2002Q1 ---<2.92 MW101D 2002Q2 ---<3.12 MW101D 2002 Q3 5.84 6.18 <0.583 <3.52 MW101D 2002Q4 4.80 5.84 -<3.11 MW101D 2003 Q1 5.34 6.65 -<6.21 MW101D 2003 Q2 5.09 9.12 -<8.7 MW101D 200303 6.41 5.81 -<3.82 MW101D 2003 Q4 6.02 4.95 -<8.19 MW101D 2004Q1 6.52 1.70 <1.16 <7.09 MW101D 2004Q2 8.50 6.18 <1.23 <3.52 MW101D 2004Q3 11.20 5.85 0.52 <4.02 MW101D 2004 04 5.17 <2.02 <0.937 <5.02 MW101S 2002Q1 ---<2.78 MW101S 2002Q2 ---1.64 MW101S 2002 03 0.91 5.74 0.55 <3.15 MW101S 2002 Q4 <0.643 2.45 -<3.09 MW101S 2003 Q1 <0.769 2.82 0.38 <4.06 NOTES:Well was not sampled for analyte<50: Observed concentration was not statistically significant at 2-ca error level, reported as <MDC Bold concentrations are greater than EPA MCL 89 Table 4-2: Gross a, JI, Sr-90 and Cs-137 Concentrations (pCi/liter) in Groundwater (continued)

Sample Gross Well ID Event Alpha Gross Beta Sr-90 Cs-I 37 MW101S 2003 Q2 <2.1 3.32 <1.7 <8.3 MW101S 2003 Q3 0.85 4.86 0.33 <4.78 MW101S 2003 Q4 0.79 7.55 0.47 <9.3 MW101S 2004Q1 <0.977 1.87 <1.2 <4.31 MW101S 2004Q2 1.59 3.27 <1.2 <3.59 MW101S 2004Q3 1.38 4.32 <0.938 <4.76 MW101S 2004Q4 <1.31 3.05 <0.98 <5.36 MW102D 2002 Q1 9.74 7.42 <0.664 <2.41 MW102D 200202 5.53 6.97 <0.721 1.98 MW102D 2002 Q3 8.93 8.69 <0.636 6.14 MW102D 2002 Q4 5.55 50.1 <0.85 6.69 MW102D 2003 Q1 3.57 15.60 <0.578 12.70 MW102D 2003 Q2 8.60 58.1 <1.6 <6.1 MW102D 2003 03 ---MW102D 2003Q4 11.10 11.10 <1.25 <8.71 MW102D 2004Q1 11.30 6.89 <1.11 <3.92 MW102D 2004 Q2 8.51 9.95 0.93 <3.43 MW102D 2004 Q3 7.38 5.64 <0.805 <3.58 MW102D 2004 Q4 10.40 8.60 <0.636 <5.14 MW102S 2002Q1 1.05 6.15 <0.716 <3.05 MW102S 2002Q2 1.48 4.52 <0.716 <3.01 MW102S 2002Q3 1.01 5.16 <0.52 <2.98 MW102S 2002 Q4 0.76 3.05 <0.644 <3.4 MW102S 2003 Q1 <0.84 4.68 0.38 <4.85 MW102S 2003Q2 1.52 4.70 1.08 <10 MW102S 2003 Q3 0.94 5.73 0.55 <4.61 MW102S 2003Q4 <1.28 4.95 <1.26 <7.25 MW102S 2004 Q1 <1.5 2.28 <1.2 <3.67 MW102S 2004Q2 1.66 2.05 <1.2 <5.06 MW102S 2004Q3 1.24 6.51 <1.3 27.20 MW102S 2004Q4 <1.65 2.43 <1.13 <2.19 MW103D 2002 Q1 3.07 3.38 <0.603 <2.78 MW103D 2002 Q2 6.87 7.39 <0.691 <2.19 MW103D 2002 Q3 8.63 12.90 <0.63 <3.64 MW103D 2002 Q4 4.64 5.42 <0.593 <3.3 MW103D 2003Q1 4.11 5.68 <1.78 <3.58 MW103D 2003 Q2 <2.6 4.85 <1.9 <7.3 MW103D 2003Q3 ---MW103D 2003 Q4 4.40 6.70 0.37 <7.7 MW103D 2004 Q1 5.19 6.06 <0.815 <2.7 MW103D 2004 Q2 2.72 3.36 1.26 <2.23 MW103D 2004 Q3 4.37 1.82 <0.895 <2.9 NOTES Well was not sampled for analyte<50: Observed concentration wvas not statistically significant at 2-a error level, reported as <MDC Bold concentrations are greater than EPA MCL 90 Table 4-2: Gross a, P1, Sr-90 and Cs-137 Concentrations (pCi/liter) in Groundwater (continued)

Sample Gross Well ID Event Alpha Gross Beta Sr-90 Cs-1 37 MW103D 2004 Q4 5.97 5.14 <1.0 <3.6 MW103S 2002Q1 1.85 37.6 5.23 30.20 MW103S 2002Q2 1.64 81.5 15.3 58.50 MW103S 2002Q3 1.57 46.0 3.81 38.10 MW103S 2002 Q4 0.68 40.6 5.57 38.00 MW103S 2003 Q1 4.33 76.9 6.75 87.60 MW103S 2003Q2 <0 42.2 1.13 26.60 MW103S 2003Q3 1.25 41.8 2.59 38.10 MW103S 2003Q4 1.05 13.5 <0.615 13.50 MW103S 2004 Q1 1.53 27.8 2.27 22.40 MW103S 2004 02 2.33 23.5 1.34 7.50 MW103S 2004 Q3 17.5 47.6 3.67 2.62 MW104S 2002 Q1 ---<5.23 MW104S 2002 Q2 ---<2.2 MW104S 2002 Q3 2.85 14.8 -<3.35 MW104S 2002Q4 1.01 6.90 -<3.09 MW104S 2003 Q1 0.73 7.56 -<5.23 MW104S 2003 02 6.10 42.87 3.14 <8.5 MW104S 2003 03 3.86 18.00 2.02 <4.29 MW104S 2003Q4 1.52 9.06 0.86 <8.76 MW104S 2004Q1 1.25 4.11 <0.685 <2.09 MW104S 2004 02 2.49 6.23 <1.35 <2.26 MW104S 2004 Q3 1.06 4.76 <0.962 <4.19 MW104S 2004 Q4 <2.14 5.59 <0.862 <3.39 MW105D 2002Q1 1.47 4.72 <0.571 <2.67 MW105D 2002Q2 1.39 2.33 <0.597 <2.26 MW105D 2002 Q3 3.06 6.69 <0.738 <3.17 MW105D 2002 Q4 2.15 5.72 <0.596 <3.12 MW105D 2003 Q1 2.43 4.46 0.66 <4.17 MW105D 2003Q2 3.59 9.01 <1.5 <7.9 MW105D 2003 Q3 6.70 6.62 <0.427 <3.47 MW105D 2003Q4 5.08 5.78 1.33 <10.10 MW105D 2004 Q1 2.59 3.56 <0.811 <2.48 MW105D 2004Q2 5.30 5.67 1.11 <2.33 MW105S 2002Q1 1.11 242. 122. <2.48 MW105S 2002 Q2 <1.34 238. 116. <2.55 MW105S 2002Q3 <1.17 180. 101. <3.29 MW105S 2002 Q4 <0.872 159. 83.3 <3.37 MW105S 2003 Q1 <1.04 253. 138. <4.23 MW105S 2003 Q2 <3.2 490. 181.6 <4.7 MW105S 2003 Q3 <1.69 45.50 197. <3.64 MW105S 2003 Q4 0.79 297. 27.6 <8.14 NOTES Well was not sampled for analyte<50: Observed concentration was not statistically significant at 2-a error level, reported as <MDC Bold concentrations are greater than EPA MCL 91 Table 4-2: Gross a, JI, Sr-90 and Cs-137 Concentrations (pCi/litcr) in Groundwater (continued)

Sample Gross Well ID Event Alpha Gross Beta Sr-90 Cs-1 37 MW105S 2004 Q1 <1.2 192. 91.8 < 1.86 MW105S 2004 Q2 <2.01 44.30 16.2 < 2.03 MW106D 2002 Q1 1.03 5.89 <0.597 <3.18 MW106D 2002 Q2 1.13 6.01 <0.527 1.92 MW106D 2002Q3 1.16 8.31 <0.546 <2.4 MW106D 2002 Q4 1.43 4.27 <0.624 <2.4 MW106D 2003 Q1 1.19 7.40 0.36 <3.97 MW106D 2003Q2 3.02 10.94 <1.5 <10 MW106D 2003 Q3 2.45 10.30 0.80 <4.25 MW106D 2003 Q4 4.76 7.73 0.50 <6.9 MW106D 2004Q1 2.75 4.12 <1.17 <2.24 MW106D 2004Q2 1.16 3.23 <1.2 <2.11 MW106D 2004 Q3 4.62 6.41 <0.991 <3.82 MW106D 2004 Q4 14.00 14.70 <0.524 <3.66 MW106S 2002 Q1 1.36 25.40 8.38 < 2.05 MW106S 2002 Q2 <1.24 34.00 13.0 < 2.28 MW106S 2002Q3 <1.49 11.20 2.26 2.76 MW106S 2002 Q4 <1.26 23.20 9.35 < 2.55 MW106S 2003 Q1 1.01 36.10 13.5 < 4.54 MW106S 2003 Q2 <3.1 54.6 18.68 < 8.5 MW106S 2003 Q3 <5.33 801. 3.71 <4.77 MW106S 2003 Q4 2.25 19.70 4.35 <9.28 MW106S 2004 Q1 1.54 13.90 1.21 <1.98 MW106S 2004 02 2.73 19.50 3.17 <2.61 MW106S 2004 Q3 3.86 36.00 7.30 <3.66 MW106S 2004 Q4 <3.57 39.30 8.56 < 4.08 MW107D 2002Q1 1.98 5.38 <0.628 <3.11 MW107D 2002 Q2 1.30 3.87 <0.6 <2.65 MW107D 2002 Q3 0.81 5.30 <0.557 <2.64 MW107D 2002 Q4 1.10 3.97 <0.572 <2.75 MW107D 2003 Q1 1.16 4.02 -<3.87 MW107D 2003 Q2 <0 4.40 <1.7 <5.4 MW107D 2003 Q3 <2.56 3.72 0.33 <4.25 MW107D 2003 Q4 0.92 3.01 <0.669 <9.04 MW107D 2004Q1 1.33 5.79 <1.23 <4.4 MW107D 2004 Q2 <2.53 7.00 <1.2 <3.61 MW107D 2004 Q3 <1.58 5.68 <0.708 <5.6 MW107D 2004 Q4 <1.43 <2.18 <0.639 <3.33 MW107S 2002Q1 --<4.37 MW107S 2002 Q2 <0.944 4.61 0.26 <2.42 MW107S 2002Q3 <1.14 5.11 <0.593 <3.43 MW107S 2002 Q4 <0.822 2.77 0.44 <2.65 NOTES Well was not sampled for analyte<50: Observed concentration was not statistically significant at 2-o error level, reported as <MDC Bold concentrations are greater than EPA MCL 92 Table 4-2: Gross a, P, Sr-90 and Cs-137 Concentrations (pCi/liter) in Groundwater (continued)

Sample Gross Well ID Event Alpha Gross Beta Sr-90 Cs-137 MW107S 2003 Q1 0.63 3.49 0.54 <3.29 MW107S 2003Q2 <2.7 4.20 <1.9 <7.6 MW107S 2003 Q3 <0.923 4.40 0.36 <5.18 MW107S 2003 Q4 <1.29 1.73 0.54 <9.23 MW107S 2004 Q1 <1.28 1.55 <1.37 <3.52 MW107S 2004Q2 <2.66 1.69 2.69 <3.39 MW107S 2004 Q3 2.39 8.01 <0.988 <3.21 MW107S 2004 Q4 1.21 5.62 0.84 <12.40 MW108S 2002Q1 ---<4.16 MW108S 2002 Q2 ---<2.25 MW108S 2002 Q3 1.16 9.36 -<3.25 MW108S 2002 Q4 0.55 2.51 -<2.31 MW108S 2003 01 0.46 2.16 -<4.8 MW108S 2003 Q2 <2.5 4.00 -<4.3 MW108S 2003 Q3 0.82 2.51 -<4.61 MW108S 2003 Q4 1.45 2.79 0.63 <9.08 MW108S 2004 Q1 <1.11 2.63 <0.887 <3.6 MW108S 2004 Q2 3.90 5.72 <1.4 <3.43 MW108S 2004 Q3 0.83 4.12 0.46 <3.1 MW108S 2004 Q4 <1.62 3.46 <0.812 6.61 MW109D 2002 01 3.70 7.47 <0.666 <2.6 MW109D 2002 Q2 4.62 5.54 <0.495 <2.52 MW109D 2002 Q3 3.72 6.20 <0.568 <2.13 MW109D 2002 04 <0.834 1.82 <0.646 <3.13 MW109D 2003Q1 6.52 11.90 -2.40 MW109D 2003Q2 9.00 11.49 <1.9 <8.2 MW109D 2003 Q3 0.91 5.57 <0.39 <4.34 MW109D 2003 Q4 --<0.497 _MW109D 2004 Q1 6.95 7.60 <1.01 <2.02 MW109D 2004Q2 7.78 9.21 <1.16 <8.77 MW109D 2004 Q3 6.18 4.19 <0.732 <4.66 MW109D 2004 Q4 5.08 6.38 <0.609 <3.14 MW109S 2002 Q1 <1.54 6.33 0.90 <2.88 MW109S 2002 Q2 <1.23 8.49 0.66 <2.76 MW109S 2002 Q3 <1.79 12.80 0.97 <3.25 MW109S 2002 Q4 1.25 10.10 0.90 <3.47 MW109S 2003 Q1 <1.5 7.85 0.98 <3.8 MW109S 2003Q2 <2.9 11.20 <1.7 <6.1 MW109S 2003Q3 <2.61 11.50 0.69 1.87 MW109S 2003Q4 <2.03 10.80 1.01 <9.7 MW109S 2004 01 <1.37 9.63 <1.11 <3.36 MW109S 2004 Q2 <2.32 6.53 0.80 <2.08 NOTES: Well was not sampled for analyte<50: Observed concentration was not statistically significant at 2-a error level, reported as <MDC Bold concentrations are greater than EPA MCL 93 Table 4-2: Gross a, p, Sr-90 and Cs-137 Concentrations (pCi/liter) in Groundwater (continued)

Sample Gross Well ID Event Alpha Gross Beta Sr-90 Cs-137 MW109S 2004 Q3 < 2.01 9.04 0.38 < 7.89 MW109S 2004 Q4 < 1.35 < 2.31 < 1.3 4.03 MW110D 2002 Q1 11.00 12.60 < 0.562 < 2.84 MW110D 2002 Q2 7.78 9.14 < 0.52 < 2.48 MW11OD 2002 Q3 7.73 11.20 2.54 < 2.17 MW110D 2002 Q4 8.25 8.83 < 0.696 < 3.26 MW110D 2003 Q1 6.04 9.95 < 0.551 < 5.04 MW110D 2003 Q2 6.10 12.00 < 1.7 < 7.5 MW110D 2003 Q3 5.82 20.50 0.36 < 3.96 MW110D 2003 Q4 8.15 11.50 0.45 < 8.19 MW110D 2004 Q1 7.07 7.14 0.66 < 3.34 MW110D 2004 02 5.63 8.50 < 1.15 < 1.94 MW110D 2004 Q3 6.99 8.48 < 0.751 < 5.55 MW110D 2004 Q4 3.46 6.34 < 1.15 < 4.97 MWi1oS 2002 Q1 < 0.965 4.07 0.34 < 3.05 MW11oS 2002 Q2 < 0.952 6.51 < 0.545 < 2.57 MW11oS 2002 03 < 0.813 4.39 < 0.683 < 2.72 MW1iS 2002 Q4 < 0.863 4.28 < 0.528 < 2.31 MW11oS 2003 Q1 < 0.858 7.47 0.32 < 4.97 MW11oS 2003 Q2 < 2.7 7.30 < 1.6 < 4.6 MW1iS 2003 Q3 < 1.93 3.99 < 0.423 < 3.45 MW11oS 2003 Q4 < 1.22 4.70 0.44 < 6.15 MW11oS 2004 Q1 < 1.33 1.88 < 1.7 < 3.41 MW1iS 2004 Q2 < 2.44 4.35 0.69 < 3.05 MW110S 2004 Q3 < 1.78 4.46 < 0.937 < 4.98 MW11oS 2004 Q4 < 1.32 3.24 < 0.919 < 4.21 MW1iS 2002 Q1 1.00 5.31 < 0.629 < 2.42 MW1i1S 2002 Q2 < 0.696 2.76 < 0.722 < 2.8 MW111S 2002 Q3 0.54 7.39 -< 3.69 MW1i1S 2002 Q4 < 0.671 5.01 < 0.527 < 2.69 MW1i1S 2003 Q1 0.55 3.24 -<3.82 MW1iS 2003 Q2 < 2.2 5.10 < 8.5 MW1iS 2003 Q3 < 0.714 4.12 -< 4.5 MW1i1S 2003 Q4 < 0.657 5.52 0.35 < 7.09 MW111S 2004 Q1 0.73 4.95 < 0.788 < 3.06 MW111S 2004 Q2 < 2.49 2.06 < 1.11 < 2.4 MW112S 2002 01 ---< 3.35 MW112S 2002 Q2 ---<1.96 MW112S 2002 Q3 < 0.788 3.61 -<3.01 MWI12S 2002 Q4 < 0.685 1.99 -<2.11 MW112S 2003 01 < 0.717 < 2.58 -<4.92 MW112S 2003 Q2 < 2.1 2.02 <7.5 NOTES N : Well was not sampled for analyte<50: Observed concentration was not statistically significant at 2-a error level, reported as <MDC Bold concentrations are greater than EPA MCL 94 Table 4-2: Gross a, j, Sr-90 and Cs-137 Concentrations (pCi/liter) in Groundwater (continued)

Sample Gross Well ID Event Alpha Gross Beta Sr-90 Cs-137 MW112S 2003 Q3 < 0.931 2.62 -< 4.87 MW112S 2003 Q4 < 0.595 < 2.5 5.49 < 8.17 MW112S 2004 Q1 < 0.96 < 2.38 < 0.765 < 3.44 MW112S 2004 Q2 1.56 < 1.97 0.70 < 4.43 MW112S 2004 Q3 < 1.24 1.63 < 0.823 < 3.26 MW112S 2004 Q4 < 1.43 < 1.98 < 1.05 < 5.63 MW113S 2002 Q1 ---< 4.17 MW113S 2002 02 ---< 3.04 MW113S 2002 03 2.95 31.40 -< 2.94 MW113S 2002 Q4 1.82 30.30 -< 3.51 MW113S 2003 Q1 0.89 23.40 -< 2.32 MW113S 2003 Q2 < 3.2 16.80 < 1.7 < 9.7 MW113S 2003 Q3 < 3.12 23.40 0.58 < 0 MW113S 2003 Q4 < 1.53 22.70 0.84 < 9.04 MW113S 2004 01 < 1.93 16.30 0.37 < 3.16 MW113S 2004 Q2 < 2.38 8.30 0.67 < 2.26 MW113S 2004 03 < 2.88 17.50 < 0.802 < 3.28 MW113S 2004 Q4 1.09 16.20 < 1.03 2.80 MW1 14S 2002 Q1 0.68 20.70 3.63 < 3.4 MW114S 2002 Q2 0.95 17.30 3.26 < 2.65 MW114S 2002 Q3 < 0.885 11.50 1.45 < 2.99 MW114S 2002 Q4 < 0.923 11.60 2.62 < 2.89 MW114S 2003 Q1 < 3.42 49.10 16.6 < 3.83 MW114S 2003 Q2 2.98 12.96 < 1.8 < 4.3 MW114S 2003 03 < 1.94 7.24 0.73 < 3.88 MW114S 2003 Q4 < 1.17 7.70 1.15 < 9.1 MW114S 2004 Q1 < 1.79 18.50 3.92 < 4.12 MW114S 2004 02 6.29 8.11 < 1.19 < 3.68 MWI15S 2002 Q1 6.38 23.00 3.85 3.18 MW115S 2002 Q2 < 0.827 5.95 0.52 1.59 MW115S 2002 Q3 1.30 17.60 2.40 7.59 MW115S 2002 Q4 1.50 13.20 1.42 3.72 MW115S 2003 Q1 1.56 11.90 1.33 2.55 MW115S 2003 Q2 < 2.1 4.60 < 1.5 < 6.6 MW115S 2003 Q4 1.88 8.49 1.41 < 9.79 MW115S 2004 Q1 1.42 8.62 1.64 2.84 MW117S 2002 Q1 ---< 4.84 MWI17S 2002 Q2 --< 2.47 MW117S 2002 Q3 1.59 8.36 -< 3.43 MW117S 2002 Q4 < 1.27 7.66 1.28 < 3.21 MW117S 2003 Q1 0.90 8.13 1.41 < 4.38 MW117S 2003 Q2 3.80 11.66 1.40 < 9.3 NOTES Well was not sampled for analyte<50: Observed concentration was not statistically significant at 2-a error level, reported as <MDC Bold concentrations are greater than EPA MCL 95 Table 4-2: Gross a, P, Sr-90 and Cs-137 Concentrations (pCi/liter) in Groundwater (continued)

Sample Gross Well ID Event Alpha Gross Beta Sr-90 Cs-137 MW117S 2003 Q3 <2.25 9.49 1.42 <4.21 MW117S 2003 Q4 <2.24 9.65 0.77 <6.78 MW117S 2004Q1 <2.97 5.41 <1.09 <3.76 MW117S 2004 Q2 <1.44 7.28 0.79 <4.08 MWI17S 2004 Q3 <1.33 6.91 0.81 <2.3 MW17S 2004 Q4 <1.65 4.91 <1.55 <5.39 MW122D 2003 Q1 12.00 12.00 <0.693 <4.64 MW122D 2003Q2 12.60 27.70 1.21 <9.2 MW122D 2003 03 21.5 18.70 <0.398 <4.02 MW122D 2003 Q4 9.80 10.80 0.21 <9.7 MW122D 2004 Q1 6.20 6.64 0.55 3.19 MW122D 2004 Q2 7.14 5.21 3.29 <3.28 MW122D 2004 Q3 4.53 4.76 <0.852 <3.72 MW122D 2004 Q4 6.68 1.96 <0.825 <4.55 MW122S 2003Q1 1.18 6.41 1.59 <3.56 MW122S 2003Q2 <3.2 14.11 <1.7 <8.6 MW122S 2003Q3 <3.49 11.20 1.24 <2.98 MW122S 2003 Q4 <2.19 8.64 0.81 <9.97 MW122S 2004 Q1 <1.58 6.46 0.64 <3.31 MW122S 2004 Q2 4.88 8.40 0.57 <3.87 MW122S 2004 Q3 <2.47 9.86 1.23 <5.29 MW122S 2004 Q4 <1.87 <2.37 <0.936 <5.25 MW123S 2003 Q1 12.90 18.40 0.63 <4.26 MW123S 2003Q2 5.10 24.70 <1.6 <5.1 MW123S 2003Q4 7.70 14.90 1.37 <7.97 MW123S 2004 Q1 4.19 14.70 0.87 <4.31 MW123S 2004Q2 4.63 19.60 <1.34 2.46 MW123S 2004 Q3 6.37 22.10 0.55 2.45 MW123S 2004 Q4 8.04 28.60 0.52 <7.75 MW124S 2003Q1 <1.04 6.24 0.49 <4.94 MW124S 2003 Q2 <2.7 8.30 <1.6 <6.7 MW124S 2003Q4 <1.22 5.90 0.54 <8.73 MW124S 2004Q1 <1.61 5.12 <1.12 <3.32 MW124S 2004 02 <2.2 4.98 1.33 <3.22 MW124S 2004 Q3 <1.23 6.50 <0.687 <4.88 MW124S 2004 Q4 <1.51 5.54 <0.639 <3.48 MW125S 2003Q1 1.52 10.90 0.69 <4.4 MW125S 2003 Q2 <2.8 14.49 1.41 <7.4 MW125S 2003Q3 <2.17 16.30 1.17 <2.5 MW125S 2003 Q4 <2.04 15.30 6.51 <7.44 MW125S 2004 Q1 1.05 8.89 3.15 <2.86 MW125S 2004 Q2 2.36 11.80 1.78 <3.88 NOTES: Well was not sampled for analyte<50: Observed concentration was not statistically significant at 2-a error level, reported as <MDC Bold concentrations are greater than EPA MCL 96 Table 4-2: Gross a, t3, Sr-90 and Cs-137 Concentrations (pCi/liter) in Groundwater (continued)

Sample Gross Well ID Event Alpha Gross Beta Sr-90 Cs-137 MW125S 2004 Q3 < 1.39 13.50 1.93 < 2.82 MW125S 2004 Q4 < 1.7 12.70 3.08 < 2.84 MW200 2002 Q2 ---< 2.45 MW200 2002 Q4 11.40 14.20 -< 3.31 MW200 2003 Q1 2.89 4.86 -< 4.88 MW200 2003 Q2 20.2 23.40 -< 4.9 MW200 2003 Q4 0.38 2.77 -< 9.36 MW200 2004 Q4 < 0.988 2.09 < 1.18 < 3.23 MW201 2002 Q2 ---< 2.86 MW201 2002 03 0.51 4.42 -< 3.56 MW201 2002 Q4 1.39 3.90 -< 3.07 MW201 2003 Q1 < 0.661 3.07 -< 4.9 MW201 2003 Q2 < 2.6 5.50 -< 3.5 MW201 2003 Q3 < 1.24 < 2.64 -< 3.98 MW201 2003 Q4 1.89 2.49 -< 9.38 MW203 2002 Q1 0.58 1.59 < 0.48 < 2.42 MW203 2002 Q2 ---< 2.77 MW203 2002 03 < 0.861 3.30 -< 3.33 MW203 2002 Q4 < 0.593 4.04 < 0.758 < 3.21 MW203 2003 Q1 2.62 6.60 -< 4.11 MW203 2003 Q2 6.30 15.60 -< 3.3 MW203 2003 Q3 0.53 2.33 -< 4.78 MW203 2003 Q4 < 0.919 3.75 -< 5.94 MW203 2004 Q4 < 1.98 < 3.27 < 1.2 < 2.69 MW205 2002 01 ---< 3.41 MW205 2002 02 ---< 2.64 MW205 2002 Q3 < 1.27 3.01 -2.51 MW205 2002 Q4 < 0.799 2.06 -< 3.08 MW205 2003 Q1 < 0.679 < 2.54 -<3.5 MW205 2003 Q2 < 1.8 2.15 -< 3.5 MW205 2003 Q3 < 1.16 1.31 -< 3.58 MW205 2003 Q4 < 0.574 1.62 -< 8.18 MW205 2004 Q4 < 1.32 2.42 < 0.769 < 3.76 MW207 2002 Q1 0.60 3.63 < 0.565 < 3.09 MW207 2002 Q2 ---< 2.83 MW207 2002 Q3 < 0.635 4.35 -< 3.22 MW207 2002 Q4 0.49 5.40 -< 2.64 MW207 2003 Q1 < 0.642 3.08 -< 3.94 MW207 2003 Q2 < 1.9 3.48 -< 7.6 MW207 2003 Q3 < 0.571 1.48 0.44 < 9.35 MW207 2003 Q4 < 0.695 2.38 -< 9.63 MW207 2004 Q4 < 1.34 < 2.28 < 1.03 < 2.82 NOTES NT Well was not sampled for analyte<50: Observed concentration wvas not statistically significant at 2-a error level, reported as <MDC Bold concentrations are greater than EPA MCL 97 Table 4-2: Gross a, P, Sr-90 and Cs-137 Concentrations (pCi/liter) in Groundwater (continued)

Sample Gross Well ID Event Alpha Gross Beta Sr-90 Cs-137 MW208 2003 Q2 24.1 42.70 < 7.6 MW208 2003 Q3 < 0.549 4.14 -< 4.72 MW208 2003 Q4 < 0.888 3.45 0.89 < 9.88 MW208 2004 Q4 < 1.25 7.35 < 0.741 < 3.19 MW1 2004 Q2 < 0 < 1.84 0.94 < 2.41 MWM 2004 Q3 < 1.35 1.33 -< 5.15 MW1 2004 Q4 < 1.42 < 2.29 < 1.29 2.80 MW2 2002 Q4 < 0.967 2.75 0.41 < 3.09 MW2 2004 Q2 < 1.29 4.43 < 1.02 < 3.51 MW2 2004 Q3 1.04 3.47 -1.73 MW2 2004 Q4 < 2.14 7.61 < 0.91 < 7.71 MW3 2004 Q2 < 1.81 0.79 < 1.24 < 2.47 MW3 2004 Q3 < 1.93 1.53 -< 2.76 MW3 2004 Q4 < 1.62 < 2.45 < 0 < 4.21 MW4 2004 Q4 < 1.35 1.64 < 1.26 < 6.22 MW502 2004 Q2 1.65 5.02 -< 2.26 MW502 2004 Q3 0.87 6.95 -< 3.03 MW502 2004 Q4 < 1.88 5.37 -< 3.17 MW503 2004 02 3.23 1.74 -< 2.35 MW503 2004 Q3 < 1.31 < 2.05 -< 1.96 MW503 2004 Q4 < 1.3 < 2.35 -< 2.96 MW504 2004 Q2 < 1.97 3.40 -< 2.34 MW504 2004 Q3 < 1.16 4.77 -< 3.2 MW504 2004 Q4 < 1.61 5.28 -< 4.08 MW505 2004 Q2 1.82 4.88 -< 3.12 MW505 2004 Q3 0.87 6.38 -< 2.38 MW505 2004 Q4 1.08 5.36 -< 3.57 MW507D 2004 Q2 28.8 15.20 -< 2.39 MW507D 2004 Q3 40.8 19.90 -< 4.59 MW507D 2004 Q4 11.60 9.16 -< 3.72 MW507S 2004 Q2 1.42 3.95 -< 2.25 MW507S 2004 Q3 2.12 6.17 -< 4.43 MW507S 2004 Q4 1.46 5.64 -< 2.96 MW508D 2004 Q2 7.58 6.68 -< 2.76 MW508D 2004 Q3 22.3 32.50 -< 4.17 MW508D 2004 Q4 15.7 21.40 -< 15.10 MW508S 2004 Q2 < 2.28 4.50 -< 3.16 MW508S 2004 Q3 1.37 6.25 -< 10 MW508S 2004 Q4 < 2.38 7.60 < 0.931 < 5.91 EOF2 2002 01 1.03 3.43 < 0.539 < 2.36 EOF2 2002 02 ---< 2.7 EOF2 2002 Q3 < 0.919 4.61 < 3.54 NOTES: Well was not sampled for analyte<50: Observed concentration was not statistically significant at 2-a error level, reported as <MDC Bold concentrations are greater than EPA MCL 98 Table 4-2: Gross a, P, Sr-90 and Cs-137 Concentrations (pCi/liter) in Groundwater (continued)

Sample Gross Well ID Event Alpha Gross Beta Sr-90 Cs-1 37 EOF2 2002 Q4 0.63 4.90 -< 3.28 EOF2 2003 Q1 1.31 5.00 -< 5.34 EOF2 2003 Q2 < 3.1 4.30 -< 4.6 EOF2 2003 Q3 < 1.63 3.76 -< 5.57 EOF2 2003 Q4 1.20 4.33 -< 9.22 EOF2 2004 Q1 ---EOF2 2004 Q2 2.58 3.30 < 1.34 < 3.27 EOF2 2004 Q3 1.02 4.01 0.88 < 2.28 EOF2 2004 Q4 1.44 5.92 < 1.34 < 5.15 SUPPLY WELL B 2002 Q4 -< 0.579 _NOTES Well was not sampled for analyte<50: Observed concentration was not statistically significant at 2-a error level, reported as <MDC Bold concentrations are greater than EPA MCL 99 Table 4-3: Tritium Concentrations (pCi/L) in Groundwater ID* Mar'99 Apr'99 Sep'99 Jun'00 Jun'01 Dec'01 Mar'02 Jun'02 Sep'02 Dec'02 Mar'03 Jun'03 Sep'03 Dec'03 Mar'04 Jun'04 Sep'04 Dec'04 100D <700 <1000 NS < MDC < 270 <210 <271 <260 134 <293 <259 <360 <301 170 <262 <306 <344 <302 100S <700 <1000 NS NS < 270 <200 <273 <261 <284 <294 <256 <320 <310 186 <267 <284 183 <295 101D <700 <1000 NS NS < 260 <210 <280 <276 137 <275 <258 250 <309 <295 <276 <242 <258 <359 101S <700 <1000 NS < MDC < 260 <210 <284 <278 <284 <273 <255 <350 <255 233 <271 252 456 <303 102D 2,740 3,160 2,640 2,470 2,620 4,110 9,400 6,390 5,590 13,900 27,100 28,630 8,200 4,910 4,940 4,690 5,120 6,480 102S <700 <1000 NS 5,540 7,250 20,600 6,320 4,500 12,200 1,100 2,370 770 4,880 5,270 6,740 5,740 12,600 8,930 103D 22,180 17,550 19,660 20,900 20,800 8,100 12,900 13,400 12,900 10,100 10,300 11,460 10,500 9,130 12,000 6,530 8,950 10,800 103S 2,580 9,260 2,980 1,230 1,120 5,350 627 6,460 495 1,760 886 2,610 3,500 195 1,090 5,300 31,000 NS 104S <700 <1000 NS NS < 270 186 <273 <261 293 142 <258 390 <307 <255 285 241 <314 262 105D 4,590 2,450 3,030 2,150 1,360 2,110 1,780 1,510 2,060 2,390 854 1,400 905 1,240 953 1,280 NS NS 105S 138,700 67,400 23,480 15,900 12,200 1,800 1,870 7,860 4,140 8,070 5,410 4,470 4,850 3,370 5,520 3,350 NS NS 106D 3,320 1,590 5,830 1,810 1,450 14,200 1,730 1,630 2,610 1,430 1,120 1,310 1,590 1,090 1,110 1,520 2,710 3,760 106S 24,290 16,370 NS NS 780 2,130 2,450 1,130 514 1,500 2,330 1,550 332 752 542 850 1,260 415 107D <700 <1000 NS < MDC < 270 <210 217 211 214 242 481 630 647 424 732 656 776 <287 107S <700 <1000 NS < MDC < 270 219 254 274 <284 <292 346 580 <250 232 225 <352 206 <359 108S <700 < 1000 NS NS < 270 156 290 221 256 <291 <251 240 206 <287 <268 <251 340 399 109D 33,070 31,600 21,230 15,800 6,550 5,720 3,810 5,660 4,150 593 4,550 3,350 <305 4,210 4,550 3,140 3,480 3,390 109S <700 <1000 NS < MDC < 270 <240 <265 <261 <288 <276 <257 <350 <300 <242 <279 <275 <320 <349 110D 27,630 23,280 27,230 18,300 18,700 21,300 16,500 10,700 15,200 11,100 4,630 5,310 11,300 6,620 5,890 8,300 13,600 3,400 110S 3,090 <1000 2,470 2,360 1,890 3,270 2,980 1,470 2,390 2,050 1,430 1,370 1,420 1,290 2,050 1,010 1,670 1,820 1ilS <700 <1000 NS <MDC <270 <210 <273 <259 222 <292 <253 <350 299 <278 <269 233 NS NS 112S <700 <1000 NS NS <270 <240 <277 <259 <277 <293 <249 <340 <306 159 <272 <277 <286 <361 113S <700 <1000 NS NS < 270 <240 <272 <263 160 <290 149 <340 118 215 <260 180 <272 <360 114S <700 1,180 2,850 2,760 1,940 NS 3,730 1,140 1,190 927 1,530 1,070 481 1,280 1,350 6,730 NS NS 115S <700 < 1000 NS 5,550 4,500 NS 1,870 4,090 1,900 2,180 2,230 3,410 NS 2,630 5,740 NS NS NS 117S <700 < 1000 NS NS < 180 <240 <272 <261 <279 <294 <249 <340 <253 <255 <283 <324 <352 <359 122D NI NI NI NI Nl NI NI NI NI NI < 258 <360 <305 120 <298 222 <261 610 122S NI NI NI NI NI NI NI NI NI NI 720 850 895 898 750 645 621 609 123S NI NI NI NI NI NI NI NI NI NI < 260 <340 128 201 <249 <306 <266 <299 124S NI NI NI NI NI NI NI NI NI NI 4850 4,350 4,340 1,910 1,530 1,770 2,080 968 125S NI NI NI NI NI NI NI NI NI NI 1,540 1,900 873 2,110 2,350 2,170 2,390 861 AST-1 <700 <1000 NS NS < 260 144 245 NS NS NS NS NS NS NS NS NS NS NS Mat 2,630 2,320 NS 2,890 NS NS NS 2,180 NS NS NS NS NS NS NS NS NS 3,260 Sump Notes: Bold values are greater than EPA 4-mrem maximum contaminant level (MCL).(<) Non-detect reported as less than minimum detection concentration (MDC).(D) Indicates dissolved sample, all other results are for total sample.(Nl) Well not installed. (NS) Well not sampled. (NA) Well sampled but not analyzed.100 (Table 4-3: Tritium Concentrations (pCi/L) in Groundwater (continued)

C ID

  • Mar'99 Apr'99 Sep'99 Jun'00 Jun'01 Dec'01 Mar'02 Jun'02 Sep'02 Dec'02 Mar'03 Jun'03 Sep'03 Dec'03 Mar'04 Jun'04 Sep'04 Dec'04 TW-1 <700 <1000 NS NS <270 <250 <267 NS NS NS NS NS NS NS NS NS NS NS TW-3 NS NS NS NS NS <200 NS NS NS NS NS NS NS NS NS NS NS NS TW-4 NS NS NS NS NS <200 NS NS NS NS NS NS NS NS NS NS NS NS MW-1 NS NS NS NS NS <200 NS NS NS NS NS NS NS NS NS 223 <305 <363 MW-2 NS NS NS NS NS 601 NS NS NS 229 NS NS NS NS NS <397 439 <357 MW-4 NS NS NS NS NS <200 NS NS NS NS NS NS NS NS NS <245 NS <312 MW-13 <700 <1000 NS NS <270 <240 <267 NS NS NS NS NS NS NS NS NS NS <348 200 <MDC <MDC NS NS <180 NS NS <261 NS NS NS NS NS NS NS NS NS <319 201 <MDC <MDC NS NS <180 NS NS <262 NS NS NS NS NA NA NS NS NS <314 202 <MDC <MDC NS NS <180 <210 <266 NS NS NS NS NS NS NS NS NS NS <318 203 <MDC <MDC NS NS <270 <250 <267 <263 NS <329 NS NS NA NA NS NS NS <315 204 <MDC <MDC NS NS <180 <210 <266 NS NS NS NS NS NS NS NS NS NS <290 205 <MDC <MDC NS NS <180 <210 <264 <275 NS NS NS NS NA NA NS NS NS <310 206 <MDC <MDC NS NS <180 <210 <261 NS NS NS NS NS NA NA NS NS NS <311 207 <MDC <MDC NS NS <180 <250 <259 <278 NS NS NS NS <238 NA NS NS NS <286 EOF NS NS NS NS NS <210 <265 NS NS NS <249 NS NS NS NS NS NS NS Supply EOF 2 Schmidt MW502 MW503 MW504 MW505 MW507D MW507S MW508D MW508S<700 <1000 NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS<270 NS NS NS NS NS NS NS NS NS<200 NS NS NS NS NS NS NS NS NS<270<267 NS NS NS NS NS NS NS NS<263 NS NS NS NS NS NS NS NS NS<285 NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS<340 NS NS NS NS NS NS NS NS NS<302 NS NS NS NS NS NS NS NS NS<246 NS NS NS NS NS NS NS NS NS<265 NS NS NS NS NS NS NS NS NS 196 NS<302<303 276<284<306<292<270<282<306 <344 NS NS 235 <315 222 <291<294 <293 233 <301<303 <359<323 <355<296 <284<306 <360 Notes: Bold values are greater than EPA 4-mrem maximum contaminant level (MCL).(<) Non-detect reported as less than minimum detection concentration (MDC).(D) Indicates dissolved sample, all other results are for total sample.(NI) Well not installed. (NS) Well not sampled. (NA) Well sampled but not analyzed.101 (Table 4-4: Hard-to-Detect (HITD) Concentrations (pCi/L) in Groundwater (7 Well ID Sample C-14 Fe-55 NI-63 Sr-90 Tc-99 Pu-238 Pu-239,40 Pu-241 Am-241 Cm-242 Cm-243,44 E vent _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _MW100D 2004 Q1 <0.173 MW100S 2004 Q1 --------<0.196 -MW101D 2002 Q3 < 8.22 < 15.10 < 0 < 0.583 < 10.80 < 0.134 < 0.134 7.40 < 0.131 < 0.132 < 0.132 MW101D 2004 Q1 ---< 1.16 ----< 0.26 -MW101D 2004 Q2 c- -<1.23 -----MW101D 2004 Q3 --0.52 ----MW101D 2004 Q4 ---< 0.937 ------MW101S 2002 Q3 4.46 < 17.60 < 4.26 0.55 < 11.20 < 0.156 < 0.156 7.59 < 0.319 < 0.244 < 0.244 MW101S 2003 Q1 ---0.38 -< 0.284 < 0.284 6.77 < 0.254 < 0.194 < 0.194 MW101S 2003 Q2 c- -<1.7 ------MW101S 2003 Q3 ---0.33 -MW101S 2003 Q4 ---0.47 --MW101S 2004 Q1 ---1.2 ---298 MW101S 2004 Q2 ---<1.2 ----MW101S 2004 Q3 ---< 0.938 ---MW101S 2004 Q4 ---< 0.98 ------MW102D 2002 Q1 < 8.06 < 6.71 < 3.51 < 0.664 < 10.40 < 0.182 < 0.271 < 10.70 < 0.213 < 0.215 < 0.215 MW1 02D 2002 Q2 < 7.85 < 8.32 < 2.84 < 0.721 < 11.30 < 0.14 < 0.139 < 7.74 < 0.203 < 0.187 < 0.187 MW102D 2002 Q3 < 8.57 < 11.40 4.67 < 0.636 < 10.70 < 0.252 < 0.143 4.69 < 0.139 < 0.14 < 0.14 MW102D 2002 Q4 < 8.08 4.14 3.42 < 0.85 14.30 < 0.134 < 0.236 10.70 < 0.152 < 0.317 < 0.317 MW102D 2003 Q1 ---<0.578 -< 0.295 < 0.295 < 18.60 < 0.113 < 0.113 c<0.113 MW102D 2003 Q2 --< 1.6 ------MW1 02D 2003 Q4 -< 10.50 < 3.42 < 1.25 < 9.01 < 0.168 < 0.168 < 9.5 < 0.15 < 0.151 < 0.151 MW102D 2004 Q1 -< 1.11 ----< 0.259 -MW102D 2004 02 -0.93 -MW102D 2004 Q3 < 0.805 MW102D 2004 Q4 < 0.636 Notes: (<)(D)(NI)Bold values are greater than EPA 4-mrem maximum contaminant level (MCL).Non-detect reported as less than minimum detection concentration (MDC).Indicates dissolved sample, all other results are for total sample.Well not installed. (NS) Well not sampled. (NA) Well sampled but not analyzed.102 (Table 4-4: Hard-to-Detect Concentrations (pCi/L) in Groundwater (continued)

(Well ID Sample C-14 Fe-55 NI-63 Sr-90 Tc-99 Pu-238 Pu-239,40 Pu-241 Am-241 Cm-242 Cm-243,44 Event__ _ _ __ _ _ _MW102S 2002 Q1 < 8.07 2.54 < 3.88 < 0.716 < 10.50 < 0.283 < 0.19 < 11.30 < 0.133 < 0.293 < 0.293 MW102S 2002 Q2 7.32 14.20 < 2.89 < 0.716 9.75 < 0.178 < 0.208 < 9.3 < 0.0954 < 0.0959 < 0.0959 MW102S 2002 Q3 < 8.57 < 11.30 4.18 < 0.52 < 10.90 < 0.132 < 0.132 < 7.69 < 0.129 < 0.13 < 0.13 MW102S 2002 Q4 < 8.08 10.30 < 3.8 < 0.644 17.90 < 0.139 < 0.246 11.60 < 0.121 < 0.121 < 0.121 MW102S 2003 Q1 < 8.07 7.89 < 4.5 0.38 < 12.30 < 0.133 < 0.133 < 9.88 < 0.116 < 0.117 < 0.117 MW102S 2003 Q2 ---1.08 ------MW1 02S 2003 Q3 --0.55 ----MW102S 2003 Q4 --< 1.26 -----MW102S 2004 Q1 --< 1.2 ----< 0.36 MW102S 2004 Q2 --< 1.2 -----MW102S 2004 Q3 --< 1.3 ----MW102S 2004 Q4 ---< 1.13 -----MW103D 2002 Q1 < 8.06 6.27 < 3.74 < 0.603 < 10.40 < 0.199 < 0.199 9.03 0.69 < 0.159 < 0.159 MW103D 2002 Q2 < 7.85 2.86 < 2.78 < 0.691 < 11.40 < 0.0982 < 0.0981 < 7.78 < 0.239 < 0.24 < 0.24 MW103D 2002 Q3 < 8.56 < 21.10 8.01 < 0.63 < 9.89 < 0.305 < 0.305 5.27 < 0.119 < 0.12 < 0.12 MW103D 2002 Q4 < 8.08 9.04 < 3.93 < 0.593 < 12.30 < 0.263 < 0.148 14.70 < 0.111 < 0.111 < 0.111 MW103D 2003 Q1 ---< 1.78 -< 0.238 < 0.238 8.76 < 0.112 < 0.113 < 0.113 MW103D 2003 Q2 < 1.9 -----MW103D 2003 Q4 ---0.37 -----.MW103D 2004 Q1 < 150.0 < 11.70 < 6.41 < 0.815 < 11.90 < 0.103 < 0.103 < 12.10 < 0.121 < 0.099 < 0.099 MW103D 2004 Q2 < 73.50 < 12.30 < 11.80 1.26 < 8.31 < 0.414 < 0.208 < 11.40 < 0.369 < 0.349 < 0.349 MW103D 2004 03 < 11.90 < 13.60 < 15 < 0.895 < 8.37 < 0.213 < 0.0793 < 10.50 < 0.31 < 0.272 < 0.272 MW103D 2004 Q4 < 10.80 21.50 < 11.30 < 0 < 9.16 < 0.235 < 0.282 < 5.76 < 0.188 < 0.141 < 0.141 MW103S 2002 Q1 < 8.07 3.50 3.71 5.23 < 10.40 < 0.18 < 0.121 < 7.11 < 0.149 < 0.278 < 0.278 MW103S 2002 Q2 5.46 4.96 3.38 15.30 < 11.20 < 0.188 < 0.221 < 7.23 < 0.0924 < 0.156 < 0.156 MW103S 2002 Q3 < 8.56 < 11.90 6.57 3.81 9.64 < 0.151 < 0.266 7.08 < 0.12 < 0.121 < 0.121 MW103S 2002 Q4 < 8.08 8.55 < 3.7 5.57 19.00 < 0.21 < 0.119 14.50 < 0.115 < 0.116 < 0.116 MW103S 2003 Q1 < 8.07 8.81 < 10.60 6.75 < 12.40 < 0.149 < 0.263 < 9.58 < 0.128 < 0.128 < 0.128 MW103S 2003 Q2 -< 9.2 < 9.7 1.13 -< 0.23 < 2.9 0.25 -MW103S 2003 Q3 < 31.70 30.50 < 34.10 2.59 < 9.5 < 0.134 < 0.134 < 7.7 < 0.411 < 0.234 < 0.234 Notes: Bold values are greater than EPA 4-mrem maximum contaminant

(<) Non-detect with minimum detection concentration (MDC).level (MCL).103 (Table 4-4: Hard-to-Detect Concentrations (pCi/L) in Groundwater (continued)

(Well ID Sample C-14 Fe-55 NI-63 Sr-90 Tc-99 Pu-238 Pu-239,40 Pu-241 Am-241 Cm-242 Cm-243,44 E vent__ _ _ __ _ _ _ __ _ _ _ _ _ _ _MW103S 2003 Q4 < 16.90 4.23 < 3.24 < 0.615 < 8.81 < 0.165 < 0.291 < 9.67 < 0.214 < 0.122 < 0.122 MW103S 2004 Q1 < 170.0 < 10.10 < 6.46 2.27 < 10.90 < 0.0407 < 0.127 16.60 < 0.0995 < 0.218 < 0.218 MW1 03S 2004 Q2 < 11.80 < 10.80 < 13.80 1.34 <10 < 0.23 < 0.156 < 14.50 < 0.256 < 0.248 < 0.248 MW1 03S 2004 Q3 8.03 < 12.30 37.30 3.67 < 8.38 < 0.175 < 0.254 < 9.55 < 0.232 < 0.304 < 0.304 MW104S 2003 Q2 ---3.14 ------MW104S 2003 Q3 ---2.02 ------MW104S 2003 Q4 13.40 2.72 < 3.56 0.86 < 8.87 < 0.127 < 0.127 < 7.25 < 0.119 < 0.119 < 0.119 MW104S 2004 Q1 < 151.0 < 10.30 < 5.71 < 0.685 < 10.80 < 0.125 < 0.113 < 14.60 < 0.0921 < 0.0923 < 0.0923 MW104S 2004 Q2 < 11.70 < 11.60 < 12.60 < 1.35 < 8.94 < 0.293 < 0.178 < 14.40 < 0.19 < 0.211 < 0.211 MW104S 2004 Q3 14.40 < 19.30 < 14.30 < 0.962 < 6.85 < 0.37 < 0.271 < 10.60 < 0.308 < 0.4 < 0.4 MW104S 2004 Q4 < 10.80 < 17 < 6.18 < 0.862 < 8.41 < 0.149 < 0.149 < 5.19 < 0.344 < 0.403 < 0.403 MW105D 2002 Q1 < 8.07 < 6.19 < 3.48 < 0.571 0.90 < 0.221 < 0.25 < 8.84 < 0.272 < 0.242 < 0.242 MW105D 2002 Q2 < 7.85 5.10 < 0 < 0.597 < 11.30 < 0.179 < 0.101 < 5.85 < 0.247 < 0.119 < 0.119 MW105D 2002 Q3 < 8.56 < 11.70 3.61 < 0.738 < 11 < 0.128 < 0.128 5.77 < 0.11 < 0.11 < 0.11 MW105D 2002 Q4 < 8.08 8.14 2.69 < 0.596 < 12 < 0.174 < 0.174 12.50 < 0.162 < 0.0918 < 0.0918 MW105D 2003 Q1 ---0.66 -< 0.184 < 0.325 < 11.20 < 0.174 < 0.175 < 0.175 MW105D 2003 Q2 ---< 1.5 ------MW105D 2003 Q3 ---< 0.427 -MW105D 2003 Q4 ---1.33 ------MW105D 2004 Q1 < 151.0 < 6.85 < 9.67 < 0.811 < 10.30 < 0.144 < 0.0804 < 12.30 < 0.0417 < 0.0417 < 0.0417 MW105D 2004 Q2 < 74.50 < 11.80 < 13.40 1.11 < 8.36 < 0.252 < 0.18 < 11.30 < 0.358 < 0.35 < 0.35 MW105S 2002 Q1 < 8.07 4.40 2.95 122. 8.89 < 0.118 < 0.118 < 6.94 < 0.159 < 0.161 < 0.161 MW105S 2002 Q2 7.02 11.20 2.48 116. 8.57 < 0.201 < 0.17 < 5.74 < 0.12 < 0.121 < 0.121 MW105S 2002 Q3 < 8.57 < 11.70 4.35 101. 11.80 < 0.117 < 0.244 < 7.51 < 0.25 < 0.142 < 0.142 MW1 05S 2002 Q4 < 8.08 13.40 < 3.83 83.3 9.96 < 0.127 < 0.295 6.70 < 0.118 < 0.209 < 0.209 MW105S 2003 Q1 5.91 12.10 < 4.67 138. < 12.50 < 0.116 < 0.116 < 7.46 < 0.132 < 0.133 < 0.133 MW105S 2003 02 < 66 < 10 < 10 181.6 < 5.6 < 0.27 -< 3.6 < 0.32 -MW1 05S 2003 Q3 < 31.80 7.48 < 3.63 197. 6.06 < 0.48 < 0.271 < 16.60 < 0.234 < 0.236 < 0.236 MW105S 2003 Q4 < 15.90 5.76 < 3.45 27.6 < 8.95 < 0.175 < 0.174 6.40 < 0.134 < 0.134 < 0.134 MW105S 2004 Q1 < 152.0 < 7.77 < 5.51 91.8 < 10.20 < 0.085 < 0.085 < 12.50 < 0.129 < 0.142 < 0.142 Notes: Bold values are greater than EPA 4-mrem maximum contaminant

(<) Non-detect with minimum detection concentration (MDC).level (MCL).104 (Table 4-4: Hard-to-Detect Concentrations (pCi/L) in Groundwater (continued)

C Well ID Sample C-14 Fe-55 NI-63 Sr-90 Tc-99 Pu-238 Pu-239,40 Pu-241 Am-241 Cm-242 Cm-243,44 Event _ _ _ _ _ _ _ _MW105S 2004 Q2 <74.30 <12.60 <13.10 16.2 <8.33 < 0.392 <0.221 8.32 <0.207 <0.341 <0.341 MW106D 2002 Q1 <8.08 < 6.68 <3.6 < 0.597 <10.40 < 0.133 <0.197 5.52 <0.177 < 0.178 <0.178 MW106D 2002 Q2 <7.85 6.94 4.22 <0.527 <11.30 < 0.108 <0.108 <9.27 <0.22 < 0.221 <0.221 MW106D 2002Q3 <8.57 < 9.7 3.82 <0.546 <11 < 0.182 <0.378 9.68 <0.156 < 0.157 <0.157 MW106D 2002Q4 5.92 13.90 <3.86 <0.624 <12.30 <0.119 <0.21 15.40 <0.108 <0.108 <0.108 MW106D 2003Q1 ---0.36 -<0.188 <0.188 <11.30 <0.118 <0.119 <0.119 MW106D 2003Q2 ---<1.5 ------MW106D 2003 Q3 ---0.80 -MW106D 2003 Q4 ---0.50 ------MW106D 2004Q1 <151.0 <8.78 <6.61 <1.17 <10.10 <0.137 <0.178 12.10 <0.218 <0.234 <0.234 MW106D 2004 Q2 <11.90 <11.60 <13.60 <1.2 <8.99 <0.175 <0.143 <14.40 <0.275 <0.36 <0.36 MW106D 2004Q3 <11.80 <15.30 <13.90 <0.991 <8.27 <0.189 <0.189 <10.90 <0.254 <0.237 <0.237 MW106D 2004 Q4 <10.80 <19.50 <10.60 <0.524 <9.21 <0.39 <0.219 <10.10 <0.405 <0.388 <0.388 MW106S 2002 Q1 <8.07 0.80 0.90 8.38 <10.50 <0.137 <0.203 5.27 <0.172 <0.174 <0.174 MW106S 2002Q2 6.03 <6.67 2.09 13.0 <11.20 <0.196 <0.111 8.34 0.44 <0.219 <0.219 MW106S 2002 Q3 <8.57 <11.10 4.44 2.26 <10.90 <0.112 <0.197 4.40 <0.179 <0.213 <0.213 MW106S 2002Q4 <8.08 14.10 <3.79 9.35 <12.30 <0.133 <0.133 12.20 <0.158 <0.0898 <0.0898 MW106S 2003 Q1 14.40 7.54 <4.75 13.5 <12.30 <0.105 <0.105 <9.36 <0.126 <0.127 <0.127 MW106S 2003Q2 <96 <11 <6.7 18.68 <5.8 <0.2 -<3.5 0.24 -MW106S 2003Q3 <31.70 4.99 <3.62 3.71 <9.3 <0.169 <0.169 <9.59 <0.143 <0.255 <0.255 MW106S 2003 Q4 <15.90 <9.93 <3.49 4.35 <8.94 <0.135 <0.238 <7.3 <0.253 <0.254 <0.254 MW106S 2004Q1 <151.0 <8.42 <5.72 1.21 <11.10 <0.145 <0.0389 <12 <0.166 <0.263 <0.263 MW106S 2004Q2 <11.80 <11.50 <11.70 3.17 <14.40 <0.294 <0.172 <15.10 <0.264 <0.342 <0.342 MW106S 2004 Q3 <27.70 <14.60 <14.30 7.30 <8.26 <0.0922 <0.0922 <9.69 <0.265 <0.349 <0.349 MW106S 2004Q4 7.79 <17.90 <10.50 8.56 <10 <0.234 <0.362 <12.10 <0.378 <0.436 <0.436 MW107D 2002Q1 <8.23 0.70 1.00 <0.628 <11.20 <0.196 <0.11 4.36 <0.124 <0.223 <0.223 MW107D 2002Q2 <7.84 0.50 <3.11 <0.6 8.25 <0.091 <0.0909 <7.18 <0.204 <0.188 <0.188 MW107D 2002Q3 <8.21 <16.40 4.76 <0.557 <11.10 <0.219 <0.124 6.46 <0.143 <0.144 <0.144 MW107D 2002Q4 <7.88 <5.83 <3.66 <0.572 <11.40 <0.161 <0.161 10.70 <0.12 <0.213 <0.213 MW107D 2003Q2 --<1.7 ------Notes: Bold values are greater than EPA 4-mrem maximum contaminant level (MCL).(<) Non-detect with minimum detection concentration (MDC).105 C Table 4-4: flard-to-Dctcct Concentrations (pCi/L) in Groundwater (continued)

C Well ID Sample C-14 Fe-55 Ni-63 Sr-90 Tc-99 Pu-238 Pu-239,40 Pu-241 Am-241 Cm-242 Cm-243,44 Event__ _ _ __ _ _ _MW107D 2003Q3 ---0.33 ----MW1 07D 2003 Q4 ---<0.669 -----MW107D 2004 Q1 ---<1.23 ----<0.301 MW107D 2004 Q2 ---<1.2 -----MW107D 2004 Q3 ---<0.708 ----MW107D 2004 Q4 ---<0.639 -----MW107S 2002Q2 <7.85 8.73 0 0.26 <11.20 <0.159 <0.159 <9.13 <0.0954 <0.096 <0.096 MW107S 2002Q3 4.10 <15.40 3.02 <0.593 <11.30 <0.12 <0.12 <7.84 <0.127 <0.266 <0.266 MW107S 2002Q4 <7.88 <5.56 <3.64 0.44 <11.40 <0.193 <0.109 10.30 <0.163 <0.0924 <0.0924 MW107S 2003Q1 ---0.54 -<0.329 <0.186 <11.90 <0.219 <0.124 <0.124 MW107S 2003Q2 ---<1.9 ------MW107S 2003 Q3 ---0.36 --MW107S 2003 Q4 ---0.54 ---MW107S 2004Q1 ---<1.37 --<0.373 MW107S 2004 Q2 ---2.69 ---MW1 07S 2004 Q3 ---<0.988 --MW1 07S 2004 Q4 ---0.84 --MW108 2003 Q4 ---0.63 --MW108 2004 Q1 ---<0.887 ----<0.0919 MW108S 2004Q2 ---<1.4 -----MW108 2004 Q3 ---0.46 ----MW108S 2004Q4 ---<0.812 ------MW109D 2002Q1 <8.24 4.68 3.13 <0.666 <11.40 <0.109 <0.109 6.27 <0.275 <0.158 <0.158 MW109D 2002Q2 <7.85 3.89 <2.95 <0.495 <11.10 <0.152 <0.152 <7.79 <0.211 <0.212 <0.212 MW109D 2002Q3 <8.56 <9.22 4.91 <0.568 <11.10 <0.213 <0.12 4.28 <0.257 <0.124 <0.124 MW109D 2002Q4 <8.08 11.00 <3.82 <0.646 9.88 <0.0959 <0.169 20.90 <0.121 <0.122 <0.122 MW109D 200302 ---<1.9 ------MW1 09D 2003Q3 ---<0.39 ------MW109D 2003 Q4 <15.90 <9.34 <3.56 <0.497 <9.77 <0.293 <0.293 9.51 <0.162 <0.163 <0.163 MW109D 200401 ---<1.01 < 0.373 Notes: Bold values are greater than EPA 4-mrem maximum contaminant level (MCL).(<) Non-detect with minimum detection concentration (MDC).106 C Table 4-4: flard-to-Detect Concentrations (pCi/L) in Groundwater (continued)

C Well ID Sample C-14 Fe-55 Ni-63 Sr-90 Tc-99 Pu-238 Pu-239,40 Pu-241 Am-241 Cm-242 Cm-243,44 Event _ _ _ _ _ _ _ __ _ _ _ _MW109D 2004 Q2 < 1.16 MW109D 2004 Q3 < 0.732 MW109D 2004 Q4 -< 0.609 ------MW109S 2002 Q1 4.70 9.90 < 3.94 0.90 < 11.40 < 0.108 < 0.108 4.45 < 0.159 < 0.161 < 0.161 MW1 09S 2002 Q2 < 7.85 5.35 < 3.07 0.66 < 11.40 < 0.182 < 0.242 < 9.91 < 0.1 < 0.17 < 0.17 MW109S 2002 Q3 < 8.21 < 15.30 < 4.96 0.97 < 11.30 < 0.127 < 0.224 9.06 < 0.277 < 0.367 < 0.367 MW109S 2002 Q4 < 8.08 11.10 < 4.12 0.90 11.20 < 0.173 < 0.203 13.20 < 0.131 < 0.233 < 0.233 MW109S 2003 Q1 ---0.98 -< 0.324 < 0.324 < 11.90 < 0.14 < 0.141 < 0.141 MW109S 2003 Q2 -< 1.7 ------MW109S 2003 Q3 -0.69 -MW109S 2003 Q4 -1.01 --MW109S 2004 Q1 < 1.11 -< 0.369 MW109S 2004 Q2 0.80 --MW109S 2004 Q3 0.38 -MW109S 2004 Q4 -< 1.3 ------MW110D 2002 Q1 < 8.24 5.06 < 3.99 < 0.562 10.50 < 0.21 < 0.118 3.78 < 0.183 < 0.164 < 0.164 MW110D 2002 Q2 < 7.85 5.76 < 3.12 < 0.52 < 11.10 < 0.151 < 0.151 < 7.82 < 0.231 < 0.111 < 0.111 MW110D 2002 Q3 < 8.56 < 9.96 4.15 2.54 < 11 < 0.121 < 0.121 < 7.06 < 0.286 < 0.288 < 0.288 MW110D 2002 Q4 < 8.08 8.85 < 3.9 < 0.696 9.99 < 0.177 < 0.37 21.30 < 0.213 < 0.121 < 0.121 MW110D 2003 Q1 -< 0.551 -< 0.158 < 0.158 < 9.8 < 0.147 < 0.147 < 0.147 MW110D 2003Q2 -< 1.7 ------MW110D 2003 Q3 -0.36 ----MW110D 2003 Q4 -0.45 -----MW11OD 2004 Q1 -0.66 ----< 0.311 MW110D 2004Q2 -< 1.15 --MW110D 2004 Q3 < 0.751 -MW110D 2004Q4 -< 1.15 ------MWi1oS 2002 Q1 < 11 4.05 3.10 0.34 8.44 <0.12 <0.119 6.91 < 0.169 < 0.171 < 0.171 MW11OS 2002 02 4.19 10.60 < 3.07 < 0.545 7.58 < 0.196 < 0.231 < 7.57 < 0.122 < 0.123 < 0.123 MW11OS 2002 Q3 < 8.57 < 10.60 < 5.32 < 0.683 < 10.80 < 0.134 < 0.237 4.12 < 0.13 < 0.131 < 0.131 Notes: Bold values are greater than EPA 4-mrem maximum contaminant level (MCL).(<) Non-detect with minimum detection concentration (MDC).107 (Table 4-4: Hard-to-Detect Concentrations (pCi/L) in Groundwater (continued)

(Well ID Sample C-14 Fe-55 NI-63 Sr-90 Tc-99 Pu-238 Pu-239,40 Pu-241 Am-241 Cm-242 Cm-243,44_ _ _ _ _ _ _ _ _ _ E v e n t _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _MWi1oS 2002 Q4 < 7.88 < 6.23 < 3.79 < 0.528 < 11.50 < 0.129 < 0.228 13.20 < 0.104 < 0.105 < 0.105 MWM1OS 2003 Q1 ---0.32 -< 0.242 < 0.241 < 15.10 < 0.116 < 0.117 < 0.117 MW110S 2003Q2 ---< 1.6 -----MW110S 2003 Q3 ---< 0.423 ----MW110S 2003 Q4 ---0.44 -----MWi1oS 2004 Q1 ---<1.7 ----< 0.354 MW11oS 2004 Q2 ---0.69 -----MW11oS 2004 Q3 ---< 0.937 ----MWiloS 2004 Q4 ---< 0.919 -----MW111S 2002 Q1 < 8.24 5.61 < 4.15 < 0.629 1.00 < 0.198 < 0.112 6.14 < 0.169 < 0.303 < 0.303 MW1i1S 2002 Q2 < 7.85 4.48 4.14 < 0.722 < 11.30 < 0.0885 < 0.0884 < 8.24 < 0.178 < 0.179 < 0.179 MW111S 2002 Q4 < 7.88 < 5.4 < 3.68 < 0.527 < 11.60 < 0.0992 < 0.175 6.12 < 0.209 < 0.247 < 0.247 MW111S 2003 Q4 -0.35 ------MW111S 2004 Q1 < 0.788 < 0.264 MW111S 2004 Q2 -< 1.11 -MW112S 2003 Q4 --5.49 ---MW1 12S 2004 Q1 ---< 0.765 --< 0.0936 MW112S 2004 Q2 ---0.70 ---MW112S 2004 Q3 ---< 0.823 --MW112S 2004 Q4 ---< 1.05 --MW113S 2003 Q2 ---< 1.7 --MW113S 2003 Q3 ---0.58 MW113S 2003 Q4 ---0.84 -----MW113S 2004 Q1 ---0.37 ----< 0.248 MW113S 2004 Q2 ---0.67 -----MW113S 2004 Q3 ---< 0.802 ----MW113S 2004Q4 ---< 1.03 -----MW114S 2002 Q1 < 8.07 4.84 < 3.61 3.63 7.14 < 0.187 < 0.125 5.81 < 0.247 < 0.168 < 0.168 MW1 14S 2002 Q2 < 7.84 2.17 < 2.61 3.26 < 11.20 < 0.11 < 0.109 < 7.52 <0.119 <0.12 < 0.12 MW114S 2002 Q3 < 8.56 < 10.70 < 3.93 1.45 < 11.10 < 0.462 < 0.261 7.83 < 0.125 < 0.126 < 0.126 Notes: Bold values are greater than EPA 4-mrem maximum contaminant

(<) Non-detect with minimum detection concentration (MDC).level (MCL).108 (Table 4-4: Hard-to-Detect Concentrations (pCi/L) in Groundwater (continued)

(Well ID Sample C-14 Fe-55 Ni-63 Sr-90 Tc-99 Pu-238 Pu-239,40 Pu-241 Am-241 Cm-242 Cm-243,44 E v en t _ _ _ _ _ _ _ _ ___ _ _ __ _ _ _ _ _ _ _ _MW114S 2002 Q4 < 8.08 7.58 < 3.65 2.62 14.70 < 0.157 < 0.157 11.50 < 0.129 < 0.229 < 0.229 MW114S 2003 Q1 < 8.07 7.43 < 4.67 16.6 < 12.30 < 0.253 < 0.143 < 11.20 < 0.214 < 0.122 < 0.122 MW114S 2003 02 -< 1.8 -----MW114S 2003 Q3 -0.73 ----MW114S 2003 Q4 -1.15 -----MW114S 2004 Q1 -3.92 ----< 0.259 MW114S 2004Q2 ---< 1.19 -----MW115S 2002 Q1 < 8.07 7.19 < 3.89 3.85 < 10.60 < 0.165 < 0.245 < 9.5 < 0.183 < 0.274 < 0.274 MW115S 2002 Q2 < 7.85 < 8.14 < 2.41 0.52 < 11.30 < 0.112 < 0.111 < 6.8 < 0.131 < 0.131 < 0.131 MW115S 2002 Q3 < 8.56 < 11.90 3.39 2.40 < 10.90 < 0.202 < 0.201 11.60 < 0.232 < 0.132 < 0.132 MW115S 2002 Q4 < 8.08 < 15.10 < 3.85 1.42 < 12.20 < 0.145 < 0.145 11.30 < 0.224 < 0.266 < 0.266 MW115S 2003 Q1 ---1.33 -< 0.146 < 0.146 < 9.29 < 0.226 < 0.128 < 0.128 MW115S 200302 --< 1.5 ------MW115S 2003 Q4 ---1.41 -----MW115S 2004 Q1 ---1.64 ----<0.198 MW117S 2002 Q4 ---1.28 ------MW117S 2003 Q1 ---1.41 ------MW117S 2003 Q2 ---1.40 ------MW117S 2003 Q3 ---1.42 ------MW117S 2003 Q4 ---0.77 ------MW117S 2004 Q1 ---<1.09 ----< 0.27 -MW117S 2004 Q2 ---0.79 ------MW117S 2004 Q3 ---0.81 ----MW117S 2004 Q4 ---< 1.55 ------MW122D 2003 Q1 ---< 0.693 -< 0.108 < 0.108 -< 0.198 < 0.234 < 0.234 MW122D 2003 Q2 -<10 < 11 1.21 -< 0.22 -< 5.3 < 0.34 -MW122D 2003 03 ---< 0.398 ---MW122D 2003 Q4 -0.21 --MW122D 2004 Q1 -0.55 < 0.148 MW122D 2004 02 -3.29 -Notes: Bold values arc greater than EPA 4-mrem maximum contaminant level (MCL).(<) Non-detect with minimum detection concentration (MDC).109 (Table 4-4: Hard-to-Detect Concentrations (pCi/L) in Groundwater (continued)

(Well ID Sample C-14 Fe-55 NI-63 Sr-90 Tc-99 Pu-238 Pu-239,40 Pu-241 Am-241 Cm-242 Cm-243,44_ _ _ _ _ _ _ _ _ E v e n t _ _ _ _ _ _ _ __ _ _ _ _ _ _ __ _ _ _MW122D 2004 Q3 < 0.852 MW122D 2004 Q4 < 0.825 -----MW122S 2003 Q1 --1.59 -< 0.122 < 0.216 < 7.5 < 0.0932 < 0.0935 < 0.0935 MW122S 2003 Q2 < 89 < 10 <10 < 1.7 < 6.8 < 0.13 -< 4.3 < 0.35 -MW122S 2003 Q3 --1.24 -----MW122S 2003 Q4 ---0.81 ----MW122S 2004 Q1 ---0.64 ---< 0.317 MW122S 2004 Q2 ---0.57 ----MW122S 2004 Q3 ---1.23 ---MW122S 2004 Q4 ---< 0.936 ------MW123S 2003 Q1 ---0.63 -< 0.186 < 0.186 < 11.10 < 0.122 < 0.122 < 0.122 MW123S 2003 Q2 -< 9.4 < 12 < 1.6 -< 0.15 -< 0 < 0.33 -MW123S 2003 Q4 ---1.37 -----MW123S 2004 Q1 ---0.87 ----< 0.284 MW123S 2004 Q2 ---< 1.34 -----MW123S 2004 Q3 ---0.55 ----MW123S 2004 Q4 ---0.52 ------MW124S 2003 Q1 ---0.49 -< 0.163 < 0.163 < 10.10 < 0.201 < 0.114 < 0.114 MW124S 2003 Q2 < 100.0 < 9.3 < 7.7 < 1.6 < 5.3 < 0.15 -< 3.6 0.30 -MW124S 2003 Q4 ---0.54 -----MW124S 2004 Q1 --< 1.12 ----< 0.486 MW124S 2004 Q2 ---1.33 -----MW124S 2004 Q3 ---< 0.687 ----MW124S 2004 Q4 ---< 0.639 ------MW125S 2003 Q1 ---0.69 -< 0.18 < 0.102 < 6.34 < 0.114 < 0.202 < 0.202 MW125S 2003 Q2 < 100.0 < 9.7 < 7.9 1.41 < 5.7 < 0.27 -< 5.4 < 0.36 -MW125S 2003 03 -1.17 ------MW125S 2003 Q4 --6.51 --MW125S 2004 Q1 --3.15 -< 0.307 MW125S 2004 Q2 --1.78 --Notes: Bold values arc greater than EPA 4-mrem maximum contaminant level (MCL).(<) Non-detect with minimum detection concentration (MDC).110 (Table 4-4: flard-to-Detect Concentrations (pCi/L) in Groundwater (continued)

(Well ID Sample C-14 Fe-55 Ni-63 Sr-90 Tc-99 Pu-238 Pu-239,40 Pu-241 Am-241 Cm-242 Cm-243,44_____ _____ Event _ _ _ _MW125S 2004 Q3 1.93 MW125S 2004 Q4 ---3.08 ------MW200 2004 Q4 < 11 < 19.90 < 13.10 < 1.18 < 10.20 < 0.148 < 0.166 < 10.70 < 0.247 < 0.336 < 0.336 MW203 2002 Q1 < 8.24 < 5.97 < 4.22 < 0.48 13.90 < 0.187 < 0.105 3.50 < 0.254 < 0.145 < 0.145 MW203 2002 Q4 < 7.89 < 5.49 < 3.85 < 0.758 < 11.50 < 0.105 < 0.219 10.30 < 0.119 < 0.211 < 0.211 MW203 2004 Q4 < 10.90 < 19.80 < 8.26 < 1.2 < 10.30 < 0.387 < 0.309 < 11.40 < 0.244 < 0.323 < 0.323 MW205 2004 Q4 < 10.90 < 17.40 < 6.8 < 0.769 < 8.55 < 0.249 < 0.161 < 11.30 < 0.244 < 0.354 < 0.354 MW207 2002 Q1 < 8.23 4.04 < 4.02 < 0.565 < 11.40 < 0.105 < 0.105 5.14 < 0.15 < 0.151 < 0.151 MW207 2003 Q3 < 31.70 12.10 < 16.10 0.44 < 9.52 < 0.223 < 0.52 < 13 < 0.326 < 0.186 < 0.186 MW207 2004 Q4 < 10.80 < 20 < 13.40 < 1.03 6.80 < 0.399 < 0.238 < 10.10 < 0.213 < 0.389 < 0.389 MW208 2003 Q4 < 15.80 3.77 < 3.55 0.89 < 10.10 < 0.308 < 0.174 < 9.48 < 0.116 < 0.116 < 0.116 MW208 2004 Q4 < 10.90 < 18.20 < 6.63 < 0.741 < 8.57 0.13 < 0.156 < 11.90 < 0.267 < 0.394 < 0.394 MW1 2004 Q2 ---0.94 ------MW1 2004 Q4 -< 1.29 ------MW2 2002 Q4 < 7.89 < 5.72 < 3.83 0.41 < 11.40 < 0.176 < 0.0998 11.20 < 0.175 < 0.0997 < 0.0997 MW2 2004 Q2 ---< 1.02 ------MW2 2004 Q4 ---< 0.91 ------MW3 2004 Q2 ---< 1.24 ------MW3 2004 Q4 ---<0 ------MW4 2004 Q4 ---< 1.26 ------MW508S 2004 Q4 ---< 0.931 ------EOF2 2002 Q1 < 8.24 5.56 < 4.03 < 0.539 < 11.30 < 0.118 < 0.118 5.70 < 0.137 <0.139 <0.139 EOF2 2004 Q2 -< 1.34 -----EOF2 2004 Q3 0.88 EOF2 2004 Q4 < 1.34 SUPPLY 2002 Q4 < 0.579 W E L L B _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _Notes: Bold values are greater than EPA 4-mrem maximum contaminant level (MCL).(<) Non-detect with minimum detection concentration (MDC).Ill Table 4-5: Total Uranium Concentrations (pg/L) in Groundwater Well ID ATW1 CMS EP165 EP166 EP171 MW100D MW100S MW101D MW101S MW102D MW102S MW103D MW103S MW104S MW106D MW106S MW107D MW107S MW108S MW109D MW109S MW110D MW11oS MW122D MW122S MW200 MW202 MW203 MW204 MW205 MW206 MW207 MW208 Sep-04 Conc. +/- 2-o Uncert.-n.s. --n.s. --n.s. --n.s. --n.s. -8.38 +/- 0.23<0.2 16.6 1.1 0.20 0.03 9.95 0.27 1.56 0.05 6.79 0.18 27.3 1.9 0.14 0.02 8.48 0.23 1.27 0.04 1.37 0.04<0.2<0.2 9.17 +/- 0.24<0.2 15.1 +/- 1.1<0.2 0.61 +/- 0.03<0.2-n.s. --n.s. --n.s. --n.s. --n.s. --n.s. --n.s. --n.s. -Dec-04 Conc. +/- 2-a Uncert.0.11 +/- 0.01 0.80 +/- 0.03 2.43 +/- 0.09 5.29 +/- 0.14 0.67 +/- 0.03 0.28 +/- 0.03 0.08 +/- 0.01 22.4 1.4 0.13 0.01 10.5 0.7 0.80 0.03 6.76 0.17-n.s. -0.10 +/- 0.01 22.1 1.4 3.49 0.10 0.04 0.00 0.04 0.01 0.23 0.02 9.51 0.24 0.21 0.02 5.95 0.15 0.00 i 0.00 7.78 0.21 0.26 0.03 0.27 0.02-0.03 0.00 0.12 0.01 0.11 0.01 0.00 i 0.00 0.15 0.01 0.21 0.02 0.31 0.03 Notes:-n.s. -Location was not sampled during this round.(<) Non-detect with minimum detection level (MDL).112 Table 4-6: Isotopic Uranium Concentrations (pCi/L) in Groundwater WlID U-234 Conc. D U-235 Conc. MCU-238 Conc.MD Well ID +/- 2-a Uncert. MDC +/- 2-a Uncert MDC+/- 2-a Uncert MDC MW100D 1.73 +/- 0.79 0.60 0.24 +/- 0.33 0.57 2.23 +/- 0.90 0.70 MW101D 5.72 +/- 1.29 0.38 0.40 +/- 0.35 0.22 5.06 +/- 1.21 0.21 MW102D 6.20 +/- 1.26 0.64 0.26 +/- 0.27 0.34 3.00 +/- 0.87 0.43 MW103D 2.38 +/- 0.78 0.59 -0.03 +/- 0.14 0.39 2.50 +/- 0.77 0.31 MW103S 8.46 +/- 1.52 0.58 0.50 +/- 0.39 0.37 9.88 +/- 1.63 0.35 MW106D 2.17 +/- 0.71 0.43 0.09 i 0.18 0.37 2.27 +/- 0.72 0.29 MW109D 4.10 +/- 0.94 0.40 0.19 i 0.24 0.39 3.82 +/- 0.90 0.15 MW11OD 4.33 +/- 1.11 0.52 0.12 i 0.22 0.46 5.32 +/- 1.22 0.36 Table 4-7: U-234/U-238

& U-235/U Ratios in Groundwater WlIDU-234 Conc. U-238 Conc. U-234/U-238 U-235 to Total U Well ID a Uncert. 2-a Uncert. Activity Ratio (%) Mass Ratio+/- 2-a Uncert.MW100D 1.73 +/- 0.79 2.23 +/- 0.90 0.78 +/- 0.47 1.65 MW101D 5.72 +/- 1.29 5.06 +/- 1.21 1.13 +/- 0.37 1.22 MW102D 6.20 +/- 1.26 3.00 +/- 0.87 2.07 +/- 0.73 1.32 MW103D 2.38 +/- 0.78 2.50 +/- 0.77 0.95 +/- 0.43 -0.195 MW103S 8.46 +/- 1.52 9.88 +/- 1.63 0.86 +/- 0.21 0.787 MW106D 2.17 +/- 0.71 2.27 +/- 0.72 0.96 +/- 0.43 0.643 MW109D 4.10 +/- 0.94 3.82 +/- 0.90 1.07 +/- 0.35 0.78 MW11 OD 4.33 +/- 1.11 5.32 +/- 1.22 0.81 +/- 0.28 0.341 (C Table 4-8: Comparison of Total Uranium Concentrations (iiglL) in Groundlwater (Well ID MW100D MW101D MW102D MW103D MW103S MW106D MW109D MW110D U-234 Conc. +/- 2-a Unc.0.0003 +/- 0.0001 0.0009 +/- 0.0002 0.0010 +/- 0.0002 0.0004 +/- 0.0001 0.0014 +/- 0.0002 0.0003 +/- 0.0001 0.0007 +/- 0.0002 0.0007 +/- 0.0002 U-235 Conc. +/- 2-a Unc.0.138 +/- 0.035 0.203 +/- 0.053 0.131 +/- 0.033-0.013 +/- 0.003 0.215 +/- 0.056 0.055 +/- 0.014 0.072 +/- 0.018 0.051 +/- 0.013 U-238 Conc. +/- 2-a Unc.6.63 +/- 2.69 15.1 +/- 3.6 8.92 +/- 2.60 7.44 +/- 2.29 29.4 +/- 4.8 6.75 +/- 2.13 11.4 +/- 2.7 15.8 +/- 3.6 Total U (Sum)6.77 +/- 2.69 15.3 +/- 3.6 9.06 +/- 2.60 7.42 +/- 2.29 29.6 +/- 4.8 6.81 +/- 2.13 11.4 +/- 2.7 15.9 +/- 3.6 Total U (KPA)8.38 +/- 0.23 16.60 +/- 1.14 9.95 +/- 0.27 6.79 +/- 0.18 27.30 +/- 1.87 8.48 +/- 0.23 9.17 +/- 0.24 15.10 +/- 1.05%Diff-19%-8%-9%9%8%-20%25%5%Ratio 0.81 0.92 0.91 1.09 1.08 0.80 1.25 1.05 Z-score-1.19-0.71-0.69 0.55 0.89-1.56 1.68 0.41 114 Table 4-9: Major Cation and Anion Concentrations in Groundwater Na Mg Well ID cation cation (mg/I) (mg/I)MW 100D MW100S MW101D MW101S MW102D MW102S MW103D MW103S MW104S MW 106D MW106S MW107D MW107S MW108S MW109D MW109S MW110D MW11 S MW122D MW122S 7.39 6.89 6.59 7.11 17.0 4.56 15.9 50.3 24.7 12.9 77.3 11.5 36.4 4.53 14.6 78.9 11.7 19.4 26.0 97.2 1.79 5.78 2.01 1.79 3.45 3.16 3.55 0.959 7.23 2.66 78.50 3.38 4.25 1.80 6.24 4.64 6.40 5.13 0.405 6.79 K Ca Cion cation cation (mg/i)(mg/I) (mg"I)1.17 9.13 2.4 2.21 14.3 9.82 2.38 27.1 9 4.07 24.4 12.1 2.34 45.7 61.9 4.26 14.0 5.13 2.03 44.9 73.7 13.20 18.8 24.2 5.90 32.6 87.6 4.58 46.5 83.9 13.30 354. 890 3.36 13.1 23.5 3.73 33.2 119 2.35 19.0 4.47 6.54 66.3 106 13.10 74.9 213 6.98 38.0 55.8 4.98 34.3 63.8 3.17 6.53 6.27 6.41 89.6 297 anion (mg/I)16.9 7.71 18 12.9 17.6 13.2 12.8 19.4 9.22 12.1 21.4 17.2 6.95 0.358 11.4 9.01 18.1 23.8 6.95 2.96 Sulfate Carb. Bicarb.Alkalinity Alkalinity (mgm) (mg/")2 12.1 2 40.5 2 59.2 2 50.5 2 63.7 2 40.4 2 35.3 27.8 79.6 2 37.4 2 63.6 2 60.5 2 20.2 2 25.3 2 30.4 2 63.6 2 35.4 2 42.3 2 16.2 2 53.2 5.95 40.8 115 Table 5-1: Required MIDC Values Nuclide MDC Analysis Nuclide MDC Analysis Nuclide Nuclide (pCj/L) Type Gross a 3 Gas Prop. Ag-108m 50 y Spec.Gross j 4 Gas Prop. Cs-134 14 y Spec.H-3 400 LSC Cs-137 15 y Spec.C-14 200 LSC Eu-152 50 y Spec.Mn-54 50 y Spec. Eu-154 50 y Spec.Fe-55 25 LSC Eu-155 50 y Spec.Co-60 25 y Spec. Pu-238 0.5 a Spec.Ni-63 15 LSC Pu-239 0.5 a Spec.Sr-90 2 GPC Pu-241 15 LSC Nb-94 50 y Spec. Am-241 0.5 a Spec.Tc-99 15 LSC Cm-243 0.5 a Spec.Table 5-2: Field Duplicate Results (NIN'122S) for Third Quarter 2004 Sample Duplicate Analyte Concentration Concentration Units Ratio Residual Z-Score+ 2-a Uncert. + 2-a Uncert.Gross Beta 9.86 + 1.67 8.55 + 1.61 (pCi/L) 0.87 -0.13 -1.13 H-3 621 +/- 171 541 +/- 167 (pCi/L) 0.87 -0.13 -0.67 Sr-90 1.23 +/- 0.456 0.684 + 0.358 (pCi/L) 0.56 -0.44 -1.88 Boron 220 223 (pg/L) 0.99 -0.01 Na cation 97.2 94.3 (mg/L) 1.03 0.03 Mg cation 6.79 6.66 (mg/L) 1.02 0.02 CI ion 297 249 (mg/L) 1.19 0.19 K cation 6.41 6.28 (mg/L) 1.02 0.02 Ca cation 89.6 87.5 (mg/L) 1.02 0.02 Sulfate anion 2.96 2.98 (mg/L) 0.99 -0.01 Carbonate 5.95 2 (mg/L) 2.98 1.98 Alkalinity Bicarbonate 40.8 77.9 (mg/L) 0.52 -0.48 Alkalinity 116 Table 5-3: Field Duplicate Results for Fourth Quarter 2004 Sample Duplicate Sample ID Analyte Concentration Concentration Units Ratio Residual Z-Score+/- 2-a Uncert. +/- 2-c Uncert.MW102S Boron 47 48.4 (pg/L) 0.97 -2.9%MW125S Boron 308 335 (pg/L) 0.92 -8.1%MW106S Boron 802 754 (pg/L) 1.06 6.4%MW102S H-3 8930 +/- 554 9580 +/- 574 (pCi/L) 1.07 7.3% 1.63 MW102S Total U 0.795 + 0.0292 0.687 +/- 0.0259 (pg/L) 0.86 -13.6% -5.53 117 Table 5-4: Lab Duplicate Results for Third Quarter 2004 Sample Duplicate Sample ID Analyte Concentration Concentration Units Ratio Residual Z-Score+/- 2-6 Uncert. + 2-a Uncert.MW106D MW100S MW109S MW125S MW103S MW103S MW103S MW122S MW106D MW109D MW106D MW109D H-3 Gross 3 Gross f Gross p Ni-63 Ni-63 Ni-63 Sr-90 U-234 U-234 U-238 U-238 2710 + 230 2.46 +/- 1.21 9.04 +/- 1.29 13.5 +/- 1.88 37.3 +/- 9.97 37.3 +/- 9.97 37.3 +/- 9.97 1.23 +/- 0.456 2.17 +/- 0.709 4.1 +/- 0.942 2.27 +/- 0.717 3.82 +/- 0.902 0.643 0.78 2630 +/- 225 2.2 +/- 1.14 6.26 +/- 1.05 14.1 +/- 2.02 31.5 +/- 9.39 22.4 +/- 8.76 29.6 +/- 9.85 1.13 +/- 0.392 1.67 +/- 0.7 3.97 +/- 1.03 3.19 +/- 0.935 3.35 +/- 0.93 1.43 1.22 (pCi/L)(pCi/L)(pCi/L)(pCi/L)(pCi/L)(pCi/L)(pCi/L)(pCi/L)(pCi/L)(pCi/L)(pCi/L)(pCi/L)(%)(%)0.97 0.89 0.69 1.04 0.84 0.60 0.79 0.92 0.77 0.97 1.41 0.88 0.45 0.64-3.0%-10.6%-30.8%4.4%-15.5%-39.9%-20.6%-8.1%-23.0%-3.2%40.5%-12.3%-55.0%-36.1%-0.50-0.31-3.34 0.43-0.85-2.25-1.10-0.33-1.00-0.19 1.56-0.73 MW106D U-235/U total MW109D U-235/U total MW11OS MW102S MW505 MW107S MW104S MW100D MW108S MW102S MW11OS MW1 03D MW100D MW100D MW1 00D MW103D MW102S MW11OS MW102S MW11OS Bicarb. Alkalinity Bicarb. Alkalinity Boron Boron Boron Ca cation Ca cation Cl ion Cl ion Cl ion K cation Mg cation Na cation Sulfate anion Sulfate anion Sulfate anion Carb. Alkalinity Carb. Alkalinity 16.2 40.4 59.9 99.7 268 9.13 19.0 5.13 63.8 73.7 1170 1790 7390 12.8 13.2 23.8 2 2 15.2 40.4 60.3 102 277 8.83 19.6 5.14 63.4 72.7 1130 1880 7110 12.8 13.2 23.8 2 2 (mg/L)(mg/L)(pg/1)(pg/1)(pug/I)(mg/L)(mg/L)(mg/L)(mg/L)(mg/L)(pg/L)(pg/L)(Pg/L)(mg/L)(mg/L)(mg/L)(mg/L)(mg/L)1.07 1.00 0.99 0.98 0.97 1.03 0.97 1.00 1.01 1.01 1.04 0.95 1.04 1.00 1.00 1.00 1.00 1.00 6.6%0.0%-0.7%-2.3%-3.2%3.4%-3.1%-0.2%0.6%1.4%3.5%-4.8%3.9%0.0%0.0%0.0%0.0%0.0%118 Table 5-5: Lab Duplicate Results for Fourth Quarter 2004 Sample Duplicate Sample ID Analyte Concentration Concentration Units Ratio Residual Z-Score 4 2-a Uncert. + 2-a Uncert.MW113S Gross a 1.09 +/- 0.628 0.914 0.788 (pCi/L) 0.84 -16.1% -0.35 MW1 1 OD Gross a 3.46 +/- 0.797 2.88 +/- 0.927 (pCi/L) 0.83 -16.8% -0.95 MW102D Gross a 10.4 +/- 1.66 10.4 +/- 1.62 (pCVL) 1.00 0.0% 0.00 MW508D Gross a 15.7 +/- 1.97 7.51 +/- 1.62 (pCVL) 0.48 -52.2% -6.42 MW100D Gross ,3 2.7 1.16 2.47 1.54 (pCVL) 0.91 -8.5% -0.24 MW113S Gross ,B 3.24 +/- 1.07 15.4 +/- 1.69 (pCVL) 4.75 375.3% 12.16 MW110D Gross P 6.34 +/- 1 7.08 1.5 (pCVL) 1.12 11.7% 0.82 MW102D Gross P 8.6 +/- 1.34 7.7 +/- 1.35 (pCVL) 0.90 -10.5% -0.95 MW508D Gross 1 21.4 +/- 1.87 16.5 +/- 1.79 (pCVL) 0.77 -22.9% -3.79 MW122S H-3 609 +/- 195 570 +/- 266 (pCVL) 0.94 -6.4% -0.24 MW11oS H-3 1820+/-354 2030+/-363 (pCi/L) 1.12 11.5% 0.83 MW110D H-3 3400+/- 439 3900 421 (pCVL) 1.15 14.7% 1.64 MW107S Sr-90 0.838 +/- 0.533 0.897 +/- 0.485 (pCVL) 1.07 7.0% 0.16 MW125S Sr-90 3.08 +/- 0.53 2.86 +/- 0.517 (pCVL) 0.93 -7.1% -0.59 EP171 Total U 0.672 +/- 0.0271 0.687 +/- 0.0252 (pg/L) 1.02 2.2% 0.81 MW102S Total U 0.795 +/- 0.0292 0.74 +/- 0.0323 (pg/L) 0.93 -6.9% -2.53 MW3 Boron 6.9 6.36 (pg/L) 1.08 8.5%MW100D Boron 13.7 11.2 (pg/L) 1.22 22.3%MW102S dup Boron 48.4 46.2 (pg/L) 1.05 4.8%MW102S dup Boron 48.4 43.2 (pg/L) 1.12 12.0%MW508D Boron 58.9 60.4 (pg/L) 0.98 -2.5%EOF2 Boron 85.6 88.6 (pg/L) 0.97 -3.4%MW109S Boron 98.6 103 (pg/L) 0.96 -4.3%MW11OD Boron 102 103 (pg/L) 0.99 -1.0%MW100S Boron 143 109 (pg/L) 1.31 31.2%MW122S Boron 184 187 (pg/L) 0.98 -1.6%MW1iS Boron 281 292 (pg/L) 0.96 -3.8%MW125S dup Boron 308 335 (pg/L) 0.92 -8.1%MW125S dup Boron 335 316 (pg/L) 1.06 6.0%119 Table 5-6: Lab Duplicate Results for Seep Sample Events-November 2004 through February 2005 -Sample Duplicate Sample ID Analyte Concentration Concentration Units Ratio Residual Z-Score+/- 2-a Uncert. +/- 2-a Uncert.Seep 2 Seep 3 Seep 1 Seep 1 Seep 2 Seep 2 Seep 3 Seep 1 Rock Seep 1 Seep 1 Seep 2 Seep 2 Seep 3 Gross 1 Gross P H-3 H-3 H-3 H-3 H-3 Sr-90 Sr-90 Sr-90 Sr-90 Sr-90 Sr-90 55.4+/-2.5 20.5 + 2.27 3250+ 290 2660+ 248 2970 + 271 1790 + 339 1510 + 305 567 + 82.6 25.6 + 1.41 21.4 + 3.63 22.3 +/- 1.36 28.6 +/- 2.13 9.86 + 1.29 50.0 + 2.41 22.2 +/- 2.37 3360+/- 307 2860+/- 260 3010 +/- 271 1920 +/- 334 1660 +/- 311 604 +/- 77.3 24.4 +/- 1.35 15.6 +/- 2.51 23.6 +/- 1.41 23.3 +/- 1.68 10.0 +/- 1.28 (pCilL)(pCi/L)(pCi/L)(pCi/L)(pCi/L)(pCilL)(pCi/L)(pci/kg)(pCilL)(pCilL)(pCilL)(pCi/L)(pCi/L)0.90 1.08 1.03 1.08 1.01 1.07 1.10 1.07 0.95 0.73 1.06 0.81 1.01-9.7%8.3%3.4%7.5%1.3%7.3%9.9%6.5%-4.7%-27.1%5.8%-18.5%1.4%-3.11 1.04 0.52 1.11 0.21 0.55 0.69 0.65-1.23-2.63 1.33-3.91 0.15 Seep 1 Seep 2 Seep 2 Seep 3 Seep 1 Seep 3 Seep 1 Seep 3 Seep 1 Seep 3 Seep 1 Seep 3 Seep 1 Seep 3 Seep 1 Seep 3 Seep 3 Seep 3 Bicarb.Alkalinity Boron Boron Boron Ca cation Ca cation Cl ion Cl ion K cation K cation Mg cation Mg cation Na cation Na cation Sulfate anion Sulfate anion TDS TDS 77.5 508 500 215 68700 46800 115 53.3 8370 6040 5980 4400 22400 13200 22.5 14.5 354 354 78.5 521 484 217 68100 47200 115 52.8 8210 6060 5960 4500 22200 13300 22.6 15.6 344 347 (mg/L)(pg/L)(pg/L)(pg/L)(pg/L)(pg/L)(mg/L)(mg/L)(pg/L)(pg/L)(pg/L)(pg/L)(pg/L)(pg/L)(mg/L)(mg/L)(mglL)(mg/L)0.99 0.98 1.03 0.99 1.01 0.99 1.00 1.01 1.02 1.00 1.00 0.98 1.01 0.99 1.00 0.93 1.03 1.02-1.3%-2.5%3.3%-0.9%0.9%-0.8%0.0%0.9%1.9%-0.3%0.3%-2.2%0.9%-0.8%-0.4%-7.1%2.9%2.0%_ _ .120 Table 5-7: DOE QAP Lab Performance Data Summary Sample Media Gamma Alpha HTD Total Isotopic Isotopic Air Filter 96.6% 97.2% 100.% 96.9%Soil 97.2% 97.7% 100.% 97.7%Vegetation 100.% 100.% 85.7% 98.0%Water 96.9% 97.2% 91.7% 96.2%AllTotals 97.4% 97.8% 94.3% 97.1%Table 5-8: MIAPEP Lab Performance Data Summary Media Gamma Alpha HTD Falsetit Sample Isotopic Isotopic Positive Filter 100% 100% 100% -100%Water 100.% 96.7% 90.9% 66.7% 96.6%Soil 100.% 90.0% 73.3% 66.7% 92.0%All Totals 100.% 93.8% 84.2% 66.7% 94.7%Table 5-9: ERA Lab Performance Data Summary Gamma Alpha HTD Total Isotopic Isotopic 97.0% 100.% 100.% 98.7%121 Table 5-10: QC Summary for Third Quarter 2004 Sample Event Sample Type Analyte Tests Total Samples Samples 845 68.4%QC Blanks 98 7.9%QC Lab Controls 110 8.9%QC Matrix Spikes 88 7.1%QC Duplicates 95 7.7%Sample/QC Totals 1236 100%Table 5-11: QC Summary for Fourth Quarter 2004 Sample Event Sample Type Samples QC Blanks QC Lab Controls QC Matrix Spikes QC Duplicates Sample/QC Totals Analyte Tests Percent of Total Samples 991 67.4%93 6.3%103 7.0%88 6.0%196 13.3%1471 100%Table 5-12: QC Summary for Seep Sample Events Sample Type Samples QC Blanks QC Lab Controls QC Matrix Spikes QC Duplicates Sample/QC Totals Analyte Tests Percent of Total Samples 274 37.5%125 17.1%128 17.5%100 13.7%103 14.1%730 100%122 Table 5-13: Lab QC Acceptance Limits QC Category Duplicates Blank Spikes, Matrix Spikes Method Blanks GEL Acceptance Limits (%)+/- 20%+/- 25%< CRDL Table 5-14: Internal Performance Data Summary (LCS, NIS)-Method Boron/Geochem y-isotopic a-isotopic LSC GPC All Totals Sep. 2004 100%100%100%100%100%100%Dec. 2004 100%100%100%100%100%100%Seeps 90.3%100%100%94.9%100%96.5%Total 96.9%100%100%97.9%100%98.7%-123 (Tablc 5-15: Case Narrative Summary for Third Quarter 2004 (Analyte Samples Quality Issue Identified Resolution/Comments Gross a/P 100S & dup, High relative percent difference/relative error ratio Recounted samples 109S & dup Gross a/P All High hygroscopic salt content causes sample mass to Salts converted to oxide by flaming planchet, fluctuate with moisture content volatile radionuclides lost (H, C, Tc, Cs)Gross a/, Process batch Samples not scanned into process batch prior to analysis COC maintained, NCR issued Gross a/, MB False positive based on sample type Recounted sample Gross a/, 102S,102S dup, MB, Low/high recovery observed Samples were re-prepped and recounted MS, MSD C-14 Process batch High lumex or quench indicator Samples recounted C-14 104S & dup No detectable activity to calculate RPD Sample MDC used to calculate the RPD Fe-55 104S Sample not scanned into process batch prior to analysis COC maintained, NCR issued Fe-55 104S, MB Negative result greater than 3 times the counting Recounted samples uncertainty Ni-63 104S, MB Samples did not meet required analysis sensitivity MW104S was recounted.

MB reported as is. NCR (MDC>RDL) issued to document low yield in MB.Ni-63 104S & dup High relative percent difference/relative error ratio Recounted samples Sr-90 103S, 106S, 122S, Statistically significant or high Sr-90 activity results Sample results were verified by recounting at 123S,125S, 600 least 5-days from the initial scan y-isotopic 507S False positive based on duplicate analysis Sample recounted and reported.Pu a-isotopic 104S Alpha peak region-of-interest (ROI) resolution Manual integration of peak ROI Total U. Process batch High relative percent difference/relative error ratio Re-prepped samples Ions Multiple High concentrations Samples diluted prior to analysis Ions 100D,102S Software peak integration errors Manual peak integration ICP-MS 104S,107D, Serial dilution difference greater than 10% for boron, K Noted in case narrative 109S&D, QC and Na samples 124 (Table 5-16: Case Narrative Summary for Fourth Quarter 2004 (Analyte Gross a/P Gross a/ P Gross a/P Gross a/ P H-3 F1-3 H-3 Samples All 202, 203, 204, 503 Multiple 106S LCS MB 10OD&S, 101S, 104S, 106S, 122S, 123S, 503, 505 109S, 110D, 122S 103D, 106D, ATW, MB, MS, LCS, 200, 202, 203, 204, 206, 207, CMS CMS, ATW1, MB, 202, 203, 204, 206 CMS, ATW1, MB, 200, 202, 203, 204, 206, 207 MB, 200, 207 3 Quality Issue Identified High hygroscopic salt content causes sample mass to fluctuate with moisture content Statistically significant activity results Statistically significant activity results Sample did not meet required analysis sensitivity (MDC>RDL).

Volume limited by allowed sample mass The H-3 recovery (%R) was greater than acceptance criteria Sample did not meet required analysis sensitivity (MDC>RDL)Sample activity between critical level and detection limit Samples were preserved.

MW11OD was preserved but labeled as non-preserved Sample did not meet required analysis sensitivity (MDC>RDL)Negative result greater than 3 times the counting uncertainty Sample did not meet required analysis sensitivity (MDC>RDL).

Sample activity between critical level and detection limit Sample did not meet required analysis sensitivity due to limited volume (MDC>RDL)Resolution/Comments Salts converted to oxide by flaming planchet.

Volatile radionuclides may be lost (1-I, C, Tc, Cs)Samples recounted to verify results. Second count reported Samples were verified by recounting.

Recounted sample for 500-min. Reported results.Recounted LCS sample Recounted sample Recounted samples Sodium hydroxide pellets added to samples. NCR issued. Results reported.Recounted samples Recounted samples Recounted samples Recounted samples Sample was re-prepped and recounted for 500-min.NCR issued to document MDC>RDL H1-3 Fe-55 Ni-63 Ni-63 Ni-63 Sr-90 125 (Table 5-16: Case Narrative Summary for Fourth Quarter 2004 (continued)

(-Analyte Sr-90 Sr-90 Tc-99 Tc-99 y-isotopic Pu a-isotopic Pu-241 Pu-241 Am/Cm a-isotopic Am/Cm a-isotopic Am/Cm a-isotopic Am/Cm a-isotopic Am/Cm a-isotopic Am/Cm a-isotopic ICP-MS Samples CMS, 106S, 107S, 11OD, 108S, 109S, 125S MB, 106D, 122S,124S, MB, 104S, 203, 205, 207, 208, EP166 106S None EP166 204 104S All 103D EP171, 106D, 202 CMS, CMS dup, 106D, 106D dup 106D MB, 203, 206, 200 Batch Quality Issue Identified Statistically significant or high Sr-90 activity results Statistically significant Sr-90 activity results Sample activity between critical level and detection limit Suspected false positive Non-rad sample processed with rad samples Poor alpha peak resolution Sample did not meet required analysis sensitivity (MDC>RDL)Statistically significant activity results Suspected false positive for Am-241, Cm-243,244.

Negative result greater than 3 times the counting uncertainty Suspected false positive for Am/Cm High relative percent difference/relative error ratio.Relative error ratio for Cm-243,44 passes at 0.618 Poor alpha peak resolution Sample did not meet required analysis sensitivity (MDC>RDL)B serial dilution difference was greater than 10%Resolution/Comments Sample results were verified by recounting at least 5-days from the initial scan.Samples recounted and recounts were reported.Samples recounted to verify results.Recounted samples No contamination noted. NCR issued Recounted samples Recounted samples Recounted sample to confirm detect.Polonium a-recoil contamination from previous samples. Future Po, U, Th samples will be segregated.

Recounted sample Recounted sample Recounted CMS samples. NCR issued for MW106D.Recounted samples Recounted samples Noted in case narrative 126 (Table 5-17: Case Narrative Summary for Bedrock Seep Samples (Analyte Gross a/ P Samples All Gross a/P Seep 2, dup 1-1-3 H-3 Fe-55 LCS MB MB, Seep 1, dup, 2, 3 Sr-90 Seep 2, 3 Sr-90 Seep 2, dup Tc-99 Pu a-isotopic Pu-241 Pu-241 Pu-241 Am/Cm a-isotopic ICP Metals Tons Ions Anions TDS MB Seep 1, 2, 3, LCS, 1 weathered rock MB Seep 1 weathered rock Seep 1 weathered rock, MB, dup, MS, LCS Seep 1 Batch Seep 1, 2,3 Seep 3 Seep 1 Seep 1, 2, 3 Quality Issue Identified High hygroscopic salt content causes sample mass to fluctuate with moisture content High relative percent difference/relative error ratio observed Low/high recovery observed Negative result greater than 3 times the uncertainty Sample did not meet required analysis sensitivity due to limited volume (MDC>RDL)Statistically significant or high Sr-90 activity results High relative percent difference/relative error ratio observed.

%R fails at 21%. Relative error at 0.973 Blank was greater than MDC but less than RDL Poor alpha peak resolution Sample did not meet required analysis sensitivity (MDC>RDL).

Low/high recovery observed High background count observed.Poor alpha peak resolution B, Mg, K serial dilution difference

(%D) was greater than 10%High concentrations Samples run on two different instruments Matrix spike recovery outside acceptance limits for chloride and sulfate due to matrix interference Insufficient time to prep and analyze with method-specified holding time Resolution/Comments Salts converted to oxide by flaming planchet.

Volatile radionuclides may be lost (F-L, C, Tc, Cs)Samples were recounted Sample was recounted Recounted samples Samples were recounted for 120-min. NCR issued to document MDC>RDL Sample results were verified by historical data or recounting at least 5-days from the initial scan.Samples were recounted.

Issued NCR for failed RPD.Noted in case narrative Manual integration of peak ROT or recounted sample Recounted samples Sample was recounted Sample batch was recounted Recounted sample Noted in case narrative Samples diluted prior to analysis NCR issued Noted in case narrative.

NCR issued Samples analyzed as soon as possible.

NCR issued 127 Table 5-18: Summary Statistics for Third Quarter 2004# of Min. Max. Mean Sdev. Median EPA Conc.> Conc.>Nuclide Method Samples Conc. Conc. Conc. Conc. Conc. MCL 2-ca MCL (pCi/L) (pCi/L) (pCi/L) (pCi/L) (pCi/L) (pCi/L) Uncert.Gross a GPC 43 Gross P GPC 43 H-3 LSC 42 C-14 LSC 7 Mn-54 Gamma 42 Fe-55 LSC 7 Co-60 Gamma 44 Ni-63 LSC 9 Sr-90 GPC 29 Nb-94 Gamma 42 Tc-99 LSC 7 Ag-1 08m Gamma 42 Cs-1 34 Gamma 42 Cs-1 37 Gamma 44 Eu-1 52 Gamma 42 Eu-I 54 Gamma 42 Eu-155 Gamma 42 U-234 Alpha 10 U-235 Alpha 10 U-238 Alpha 10 Pu-238 Alpha 7 Pu-239,240 Alpha 7 Pu-241 LSC 7 Am-241 Gamma 42 Am-241 Alpha 7 Cm-242 Alpha 7 Cm-243,44 Alpha 7-1.08 40.80 3.84 0.42 47.60 9.12-153 31000 2211-10.00 14.40 1.13-2.61 1.35 -0.31-36.0 9.3 -3.9-3.47 44.60 1.53-6.93 37.30 12.12-0.15 7.30 0.78-2.20 3.35 0.28-4.46 1.31 -2.08-2.99 3.33 -0.24-2.38 2.44 0.32-1.89 27.20 1.16-6.81 7.69 -0.26-4.03 5.89 -0.01-9.63 12.70 0.80 1.67 8.46 4.07-0.03 0.50 0.23 2.23 9.88 4.06-0.048 0.034 -0.006-0.034 0.076 0.015-1.99 5.76 1.13-22.2 14.6 -1.3-0.007 0.099 0.044-0.041 0.038 -0.011-0.075 0.066 -0.004 7.62 1.04 9.62 6.25 5519 214 8.19 0.84 0.99 -0.09 17.0 3.7 7.18 0.32 17.78 3.99 1.46 0.34 1.03 0.42 2.31 -1.73 1.33 -0.20 1.15 0.32 4.18 0.47 3.20 -0.66 2.43 -0.12 4.19 0.58 2.22 4.04 0.15 0.25 2.31 3.27 0.025 -0.008 0.036 0.019 2.74 0.54 7.6 -0.1 0.037 0.027 0.027 -0.008 0.048 -0.009 15 50 20000 2000 300 2000 100 50 8 900 20000 20 60 200 600 20 20 20 15 15 15 15 15 15 24 42 21 2 0 0 3 4 11 1 0 0 1 5 1 1 1 8 2 8 0 0 0 2 0 0 0 Totals 683 137 5 128 Table 5-19: Summary Statistics for Fourth Quarter 2004# of Min. Max. Mean Sdev. Median EPA Conc.> Conc.>Nuclide Method Sa°f Conc. Conc. Conc. Conc. Conc. MCL 2-c o MCL Samples (pCi/L) (pCi/L) (pCilL) (pCi/L) (pCi/L) (pCi/L) Uncert.Gross a GPC 64 -0.9310 15.7000 1.8606 3.755 0.262 15 17 1 Gross 3 GPC 64 -1.080 39.300 5.9378 6.893 5.025 50 40 0 H-3 LSC -98.00 10800.0 1234.8 101.000 20000 8 C-14 LSC 18 -1.7800 7.7900 1.5013 2.281 1.310 2000 1 0 Mn-54 Gamma 65 -3.5000 2.8600 -0.3737 1.349 -0.476 300 1 0 Fe-55 LSC 19 -15.100 21.500 3.1915 11.357 4.080 2000 3 0 Co-60 Gamma 65 -3.1700 11.1000 1.1516 2.654 0.412 100 9 0 Ni-63 LSC 19 -8.190 3.950 -0.8728 3.953 0.504 50 2 0 Sr-90 GPC 52 -1.0100 8.5600 0.5043 1.356 0.209 8 10 1 Nb-94 Gamma 65 -3.7000 7.7900 0.0371 1.695 -0.060 -3 0 Tc-99 LSC 20 -3.000 6.800 1.3936 2.515 1.845 900 1 0 Ag-108m Gamma 65 -6.5900 4.4400 0.0332 1.543 0.009 -1 0 Cs-134 Gamma 65 -2.7000 5.4700 0.4961 1.461 0.434 20000 4 0 Cs-137 Gamma 65 -5.4200 6.6100 0.3957 1.982 0.263 20 5 0 Eu-152 Gamma 65 -25.9000 11.1000 -0.283 5.557 0.463 60 1 0 Eu-154 Gamma 65 -9.6300 10.7000 -0.1613 4.175 -0.754 200 2 0 Eu-155 Gamma 65 -15.8000 9.9200 -0.1997 4.908 0.149 600 1 0 Pu-238 Alpha 19 -0.1500 0.1450 -0.0025 0.082 -0.027 15 1 0 Pu-239,240 Alpha 19 -0.0704 0.0758 0.0031 0.035 0.000 15 0 0 Pu-241 LSC 23 -8.430 17.500 0.2522 6.278 -1.350 -3 0 Am-241 Gamma 65 -55.4000 21.4000 -1.305 10.578 -0.207 15 2 0 Am-241 Alpha 19 -0.0590 0.2190 0.0373 0.059 0.036 15 1 0 Cm-242 Alpha 18 -0.0438 0.1830 0.0279 0.051 0.018 15 0 0 Cm-243,44 Alpha 19 -0.1310 0.0600 -0.0284 0.054 -0.034 15 0 0 Totals 1086 126 2 129 Table 5-20: Limiting Mlean Distribution Summary for Third Quarter 2004 Limiting Limiting # of LimitingFilbnsCtca Nulie Analysis en Se.Rsls Calculated Critical Ma ilbns Ciia Ncie Method Men Se.Rslst-value t-valuel Ma r-statistic r-statiStiC 2 Distribution (pCiIL) (pCiIL) (n) Bias Gross a GPC 0.3460 0.7326 27 2.454 3.590 Gross 3 GPC 1.627 0.660 7 6.523 5.625 Positive H-3 LSC 92.31 111.63 24 4.051 3.646 Positive C-14 LSC 1.13 8.19 7 0.365 5.625 -Mn-54 Gamma -0.3147 0.9901 42 -2.060 3.440 -Fe-55 LSC 5.4253 3.9312 5 3.086 7.959 -Co-60 Gamma 0.2405 1.0820 41 1.423 3.446 -Ni-63 LSC -2.338 3.982 5 -1.313 7.959 -Sr-90 GPC 0.2559 0.2101 22 5.713 3.693 Positive Nb-94 Gamma 0.3321 0.7498 39 2.766 3.460 -Tc-99 LSC -2.075 2.315 7 -2.372 5.625 -Ag-108m Gamma -0.2433 1.3315 42 -1.184 3.440 -Cs-134 Gamma 0.3208 1.1487 42 1.810 3.440 -Cs-137 Gamma 0.5553 1.1524 43 3.160 3.434 -Eu-152 Gamma -0.2570 3.1988 42 -0.521 3.440 -Eu-154 Gamma -0.0146 2.4334 42 -0.039 3.440 -Eu-155 Gamma 0.7960 4.1928 42 1.230 3.440 -U-234 Alpha 1.9875 0.3437 4 11.565 11.675 -U-235 Alpha 0.2341 0.1534 10 4.826 4.568 Positive U-238 Alpha 2.3333 0.1457 3 27.738 27.190 Positive Pu-238 Alpha -0.0058 0.0253 7 -0.607 5.625 -Pu-239,240 Alpha 0.0149 0.0358 7 1.101 5.625 -Pu-241 LSC 1.135 2.738 7 1.097 5.625 -Am-241 Alpha -2.3447 5.3125 37 -2.685 3.475 -Am-241 Gamma 0.044 0.037 7 3.173 5.625 -Cm-242 Alpha -0.0106 0.0269 7 -1.043 5.625 -Cm-243 Alpha -0.0040 0.0479 7 -0.221 5.625 -0.981 0.96 0.988 0.899 0.962 0.957 0.988 0.899 0.984 0.973 0.96 0.879 0.985 0.973 0.942 0.879 0.981 0.954 0.984 0.971 0.954 0.899 0.986 0.973 0.98 0.973 0.993 0.973 0.994 0.973 0.985 0.973 0.985 0.973 0.956 0.868 0.987 0.917 0.926 0.879 0.974 0.899 0.984 0.899 0.97 0.899 0.986 0.969 0.974 0.899 0.961 0.899 0.997 0.899 Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Normal Notes: 'Student t-statistic at the 99% Confidence Interval for n-I degrees of freedom 2 Filliben's r-statistic at the 95% Confidence Interval for n degrees of freedom 130 Table 5-21: Limiting Alean Distribution Summary for Fourth Quarter 2004 AnlssLimiting Limiting # ofCacltd ricl LimitingFilbnsCtca Nuclide Analysis Mean Sdev. Results Calculated Critical Mean iFiliben's sCrtical 2 Distribution Method (pCiIL) (pCiIL) (n) t-value t-valuel Bias r-statistic r-statisi Gross a GPC -0.014 0.449 44 -0.213 3.428 -0.996 0.974 Normal Gross C GPC 1.244 1.005 27 6.434 3.590 Positive 0.983 0.96 Normal H-3 LSC 51.50 83.62 41 3.944 3.446 Positive 0.983 0.973 Normal C-14 LSC 1.131 1.706 17 2.735 3.872 -0.979 0.942 Normal Mn-54 Gamma -0.374 1.349 65 -2.234 3.352 -0.994 0.982 Normal Fe-55 LSC 3.192 11.357 19 1.225 3.787 -0.982 0.947 Normal Co-60 Gamma 0.398 1.346 58 2.255 3.371 -0.991 0.98 Normal Ni-63 LSC -0.873 3.953 19 -0.962 3.787 -0.956 0.947 Normal Sr-90 GPC 0.140 0.221 41 4.069 3.446 Positive 0.986 0.973 Normal Nb-94 Gamma -0.084 1.396 64 -0.482 3.355 -0.986 0.981 Normal Tc-99 LSC 1.394 2.515 20 2.478 3.752 -0.972 0.95 Normal Ag-108m Gamma 0.027 0.905 60 0.230 3.365 -0.996 0.981 Normal Cs-134 Gamma 0.361 1.260 63 2.276 3.357 -0.995 0.981 Normal Cs-137 Gamma 0.236 1.482 61 1.245 3.362 -0.988 0.981 Normal Eu-152 Gamma 0.117 4.560 64 0.206 3.355 -0.985 0.981 Normal Eu-154 Gamma -0.161 4.175 65 -0.311 3.352 -0.993 0.982 Normal Eu-155 Gamma 0.044 4.532 64 0.078 3.355 -0.998 0.981 Normal Pu-238 Alpha -0.003 0.082 19 -0.133 3.787 -0.989 0.947 Normal Pu-239,240 Alpha 0.003 0.035 19 0.387 3.787 -0.988 0.947 Normal Pu-241 LSC -2.178 3.696 20 -2.635 3.752 -0.956 0.95 Normal Am-241 Alpha 0.027 0.040 18 2.856 3.827 -0.982 0.945 Normal Am-241 Gamma -1.120 7.379 62 -1.195 3.360 -0.996 0.981 Normal Cm-242 Alpha 0.019 0.034 17 2.295 3.872 -0.99 0.942 Normal Cm-243 Alpha -0.028 0.054 18 -2.223 3.827 -0.986 0.945 Normal Notes: 'Student t-statistic at the 99% Confidence Interval for n-I degrees of freedom 2 Filliben's r-statistic at the 95% Confidence Interval for n degrees of freedom 131 Table 5-22: Observed False-Positive Rates Analysis Type Gamma Isotopic Alpha Isotopic HTD Beta via LSC September 2004 December 2004 Average Rate 2.9% 4.5% 3.9%0.0% 1.2% 0.8%7.0% 6.7% 6.7%Table 5-23: Data Quality Metrics-Parameter Precision Accuracy Representativeness Completeness Comparability Data Quality Metric* Relative Percent Difference (RPD) < 20%* Laboratory Control Sample Recovery 100% + 25* MDC < 0.1

  • Drinking Water Standard* Laboratory Blank Analysis Results < MDC* Qualitative assessment of sample location, sample timing, sample collection method, sample preservation, handling, shipment* Valid measurements for critical samples = 100%* Qualitative assessment of sample collection and measurement methods and assignment of sample locations to hydrostratigraphic units.* Sample MDC < CRDL 132 Table 6-1: Summary of Seep SOCs in the Plant Area Well Boron Anaa i Tritium sat Sr-90 Analysis ID Date DaeDate Seep #1 3,250 24-Jan-05 25.6 24-Jan-05 Seep #1 505 16-Feb-05 2,660 5-Feb-05 21.4 5-Feb-05 Seep #2 25.5 30-Nov-04 Seep #2 3,000 24-Jan-05 24.8 24-Jan-05 Seep #2 567 16-Feb-05 2,800 5-Feb-05 24.7 5-Feb-05 Seep #2 508 21 -Feb-05 2,970 18-Feb-05 22.3 18-Feb-05 Seep #3 4.81 30-Nov-04 Seep #3 261 25-Jan-05 1,510 23-Jan-05 9.86 21-Jan-05 Seep #3 215 16-Feb-05 1,020 5-Feb-05 17.2 5-Feb-05 Seep #3 117 21 -Feb-05 262 18-Feb-05 4.63 18-Feb-05 Seep #4 ..2.79 30-Nov-04 Seep #4 351 16-Feb-05 2,650 5-Feb-05 3.14 5-Feb-05 Seep #4 415 21 -Feb-05 2,370 18-Feb-05 2.93 18-Feb-05 Seep #1 468 16-Feb-05 Not Analyzed Not Analyzed Seep #1 505 16-Feb-05 Not Analyzed Not Analyzed Seep #2 478 16-Feb-05 Not Analyzed Not Analyzed Seep #2 505 16-Feb-05 Not Analyzed Not Analyzed Seep #3 262 16-Feb-05 Not Analyzed I _ I Not Analyzed I Seep #3 277 16-Feb-05 Not Analyzed Not Analyzed Seep #4 378 16-Feb-05 Not Analyzed Not Analyzed 133 I .,dp 0P i go .go EOF/ PARKING LOT MAIN PLANT AREA AND UPPER PENINSULA AREA cot-/i i I PENINSULA AREA LANDFILL AREA BULDINGS -*- PROPERTY UNE A,~L SWAMP EOF WS:N, EOF WS 4 I I ; E4, , fy EOF-2 EOF-1-, h, , N ', , ----\SW-2 I ., ::-MW-1ooS MW-506-L I _ .i ' :-* MW503 "W.;to = , ,; , , 7 *st MW-504 m , MW-5ZD, MW-502 j4 Mt
  • AW-508S.MW-508D ROADS & PARKING AREAS DIRT ROAD= BUILDING OB-25 SURFACE WATER AT- 1 4+* SURFACE WATER MONITORING LOCATION MW-124 O MONITORING WELL MW-123S N CH2MHILL 0 100 200 Feet FIGURE 2-1 GROUNDWATER AND SURFACE WATER MONITORING LOCATIONS AT THE EOF AND PARKING LOT AREA OF THE HADDAM NECK PLANT HADDAM NECK, CT\\boomer\H\projects3\CTYankee\MXD\GW Monitoring Report 2_05\BaseMapEOF ParkingLot.mxd JKelly 3/312005 C?-t, "MW-i100Di MI-i 0051.X MV MW 101D MW103D EP-17q' 5)B-25 MW- MW-122D IVIW-122~124 M MW-1 07D\,o -M\W-lQ7S N. N 4$1 BOW-1 08S-ROADS & PARKING AREAS DIRT ROADl BUILDING SURFACE WATER* SURFACE WATER MONITORING LOCATION 4 MONITORING WELL MW-11 Os N 0 100 200_1_1I Feet FIGURE 2-2 GROUNDWATER AND SURFACE WATER MONITORING LOCATIONS AT THE INDUSTRIAL AREA AND UPPER PENINSULA AREA OF THE HADDAM NECK PLANT HADDAM NECK CT fI-HA'7 AI-4II I I.ftwm ana-m-\\boomer\Hprojects3\CTYankee\MXD\GW MonitoringReport2_05\BaseMap_lndustrialArea.mxd JKelly 3/29/2005 C03 MW-4 4 MW-2 ,- Well-A 1
  • 8-2*MW-3 -Well-B 9-2 l. -MW-i TW-2 4 -TW-3 10-2 MW-13-44 TW-4 TPW-1 4MW-1 17 TPW-2*41 TW-1 ROADS & PARKING AREAS DIRT ROAD= BUILDING SURFACE WATER$ MONITORING WELL MW-117 MW-14-41 N 0 100 200 Feet FIGURE 2-3 GROUNDWATER MONITORING LOCATIONS AT THE PENINSULA AREA OF THE HADDAM NECK PLANT HADDAM NECK, CT CH2MHILL\\boomer\H\projects3\CTYankee\MXD\GW MonitoringReport_4_2004\BaseMapPeninsula mxd NMoudry 4/12/2004

-r

,., I I:I I _-202 I ---4-11X MW-200 OUTLINE OF THE LANDFILL'--

  • MW-207*MW-204 MW-205 4 +- MW-201 OF Li-4 MW-208-OOUTLINE OF WETLANDS AREA (Ref. USGS Deep River, CT Quadrangle Map, 1971)-RROADS & PARKING AREAS DIRT ROAD L_ BUILDING SURFACE WATER+ MONITORING WELL MW-201 N 0 100 200_ _ Feet FIGURE 2-4 GROUNDWATER MONITORING LOCATIONS AT THE LANDFILL AREA OF THE HADDAM NECK PLANT HADDAM NECK, CT CH2MHILL us5\\boomer\H\projects3\CTYankee\MXD\GW Monitoring Report 4 2004\BaseMapLandfill.mxd NMoudry 4/12/2004 CT X~ <,_MW -10D MvW- I 0S M[vW 1 (X3i MW- 102S ae-- .1,2 D X > \A MAT SUMP-ROADS & PARKING AREAS DIRT ROAD SURFACE WATER:X1 BUILDING 4 MONITORING WELL SCREENED IN PERCHED AQUIFER-GROUNDWATER ELEVATION CONTOUR-* APPROXIMATE DELINEATION OF PERCHED AQUIFER 0 MAT SUMP -OPERATIONAL MW-508S MONITORING WELL ID &(10.36) GROUNDWATER ELEVATION IN FEET MEAN SEA LEVEL FIGURE 2-5 GROUNDWATER ELEVATION AND INFERRED CONTOURS AND FLOW DIRECTION IN THE PERCHED AQUIFER OF THE CONNECTICUT YANKEE HADDAN NECK PLANT AUGUST 22, 2004 11:15 HADDAM NECK. CT 9I1E.I1116MMIII I 0 125 250 Feet In Off-_w *l__\\boomer\H\projects3\CTYankee\MXD\GW MonitorngReport 2_05\Pot MapPERCHED 8 04.mxd JKelly 3/29/2005 C, t)&

N 0 A 1.. 250 Feet FIGURE 2-6 GROUNDWATER ELEVATION AND INFERRED CONTOURS AND FLOW DIRECTION IN THE UNCONFINED AQUIFER OF THE CONNECTICUT YANKEE HADDAN NECK PLANT AUGUST 22, 2004 11:15 HADDAM NECK, CT 01H2IUU4ILL I~-MV-ICT -k.~MW 2 P.IM UNCOFINED8

l. 3/1102OOS C <1 rv 100D M I 14 S MAW- I 15S MW l'(")ROADS & PARKING AREAS SURFACE WATER L_l BUILDING DIRT ROAD 4 MONITORING WELL GROUNDWATER ELEVATION CONTOUR MW-508D MONITORING WELL ID & 0 MAT SUMP -OPERATIONAL (3-96) GROUNDWATER ELEVATION IN FEET MEAN SEA LEVEL N i 0 125 250 CH2MHILL A Feet X\boomer\H\projects3\CT_Yankee\MXD\GW MonitonrngReport 2 05\Pot Map_CONFINED_8_04.mxd JKelly 3/29/2005 FIGURE 2-7 GROUNDWATER ELEVATION AND INFERRED CONTOURS AND FLOW DIRECTION IN THE CONFINED AQUIFER OF THE CONNECTICUT YANKEE HADDAN NECK PLANT AUGUST 22, 2004 11:15 HADDAM NECK, CT Co%

.MW-l00)D M1VV-101 1D M\X-1]O1s MVV- 1 03S MW- IL03D MA-I SUM4F-ROADS & PARKING AREAS DIRT ROAD I BUILDING SURFACE WATER-ji MONITORING WELL SCREENED IN PERCHED AQUIFER-GROUNDWATER ELEVATION CONTOUR 0-0-- APPROXIMATE DELINEATION OF PERCHED AQUIFER MW-SOBS MONITORING WELL ID &(9.80) GROUNDWATER ELEVATION IN FEET MEAN SEA LEVEL 0 MAT SUMP -OPERATIONAL N A 0 125 250 A _Feet FIGURE 2-8 GROUNDWATER ELEVATION AND INFERRED CONTOURS AND FLOW DIRECTION IN THE PERCHED AQUIFER OF THE CONNECTICUT YANKEE HADDAN NECK PLANT DECEMBER 1, 2004 23:55 HADDAM NECK. CT CH2MHILL\\boomerXHlprojects3\CTYankee\MXD\GW-MonitoringRepor_2_5\Pot MapPERCHED1l 2_04.mxd JXelly 3/29/2005 cc9 tv RIVER *MW-122D MW-122S 4% I(AVI t~F I 4 4 4%'4O-ROADS & PARKING AREAS SURFACE WATER 4 MW-502 (4.23)BDIRT ROAD " OBSTRUCTION TO GROUNDWATER FLOW I BUILDING -GROUNDWATER ELEVATION CONTOUR MONITORING WELL --i (DASHED WHERE INFERRED)MONITORING WELL ID & 0 MAT SUMP -OPERATIONAL GROUNDWATER ELEVATION IN FEET MEAN SEA LEVEL (3.95) 410, N FIGURE 2-9 GROUNDWATER ELEVATION AND INFERRED CONTOURS AND FLOW DIRECTION IN THE UNCONFINED AQUIFER OF THE CONNECTICUT YANKEE HADDAN NECK PLANT DECEMBER 1, 2004 23:55 HADDAM NECK. CT et&M;PRflHI I 0 125 250 Feet_- -Eli_ -Be__k\boomer~H\projects3\CT Yankee\MXD\GW MonitoringRepor_2_05\Pot MapUNCONFINED_

2-04.mxd JKelly 3129/2005 C I N 0 At ... 250 moolollollw

I Fee FIGURE 2.10 GROUNDWATER ELEVATION AND INFERRED CONTOURS AND FLOW DIRECTION IN THE CONFINED AQUIFER OF THE CONNECTICUT YANKEE HADDAN NECK PLANT DECEMBER 1, 2004 23:55 HADDAM NECK, CT C-H22MHILL ntbooommi~fo~ods3lCT VanaUMXDIGW.Momomm,_4R0od 2 05.ol _Map CONFINED_1204 mad J.dK. 311012005 C.) \

S OUTLINE OF THE INDEPENDENT FUEL STORAGE INSTALLATION

, I '-OUTLINE OF WETLANDS AREA (Ref USGS Deep River CT Ouaed.rN31 Map,-ROADS & PARKING AREAS DIRT ROAD BUILDING SURFACE WATERl MONITORING WELL ID &I M,_GROUNDWATER ELEVATION (34 591 IN FEET MEAN SEA LEVEL N A S ISS 20W llb _ Feet IlM2KUHILL I ebo IeHrses3tCT YankeeMIrJ<GW Meniren ee2o S e Map LaYt12 0 nfd JKIln 3;le/zoes CVZ-

Figure 2-13: Photographs of Seeps in Contaminated Soil Removal Area-147 -CA) L Figure 2-14: Photographs of Seeps in Contaminated Soil Removal Area-148 -

Figure 5-1: Mn-54 Rank Order for September 2004 Rank Order 0 6 10 20 30 40 a 0.C.2 C.0 (2 C 0 U).2 I I I I .I I I II. ~ H 0 ,I II II. I jI I ftH1hU44+0+{I+dtt 4-.......-.....................

__ -.,, , , -....... ---,+4i+i+t i IITTI II I II I I II I II II* Mn-54 Lim. Mean-2-Sig.+2-Sig.--Ave. MDC-6-8 Figure 5-2: Mn-54 Normality Plot for September 2004 Standard Nomal Quantile-3 1 0 1 2 3 4 o10 8-4.27 -3.28 -2.29 -1.30 -0.31 0.68 1.67 2.66 3.65 Concentration (pCI/L)-149 -

Figure 5-3: Cs-137 Rank Order for September 2004 Rank Order 20 0 10 30 40 10 U-a C 0 E C 0 U 5 0-5----------

j--- -- I --.1 11l1111111111XT t,.tit 1 4u10TIt ,.........

,, ,,1,,,,,,,,,,,,1.+*

,,.,,. ,, , ,. , I1 I IdHtltttttttttTTITIII I " II II I ' I Il* Cs-137 Lim. Mean-2-Sig.+2-Sig.-- Ave. MDC-10 Figure 5-4: Cs-137 Normality Plot for September 2004 Standard Normal Quantile-3 -2 0 2 3 18 16 14 12 D 10 C 2!0L 6-4.05 -2.90 -1.75 -0.60 0.56 1.71 2.86 4.01 5.16 Concentration (pCi/L)-150-CI-I Figure 5-5: Co-60 Rank Order for December 2004 Rank Order 0 10 20 30 40 50 60 15 r 10-5 C C 0 0 U a 0-5-10 I'Ill l Ii II .I1 i l , I I 1t111* Co-60 Lim. Mean-2-Sig.+2-Sig.-- Ave. MDC-......... .9 .. ..... ... .. .........P...........

9 IIH- tttt11TIIIHH

' IHI 'I-'1 W1 1 1 1 ' -II I 1I , , Figure 5-6: Co-60 Normality Plot for December 2004 Standard Normal Quantile-3 1 0 1 2 3 i 15 C'4,98 -3.64 -2.29 -0.95 0.40 1.74 3.09 4.44 5.78 Concentration (pCi/L)-151 -

Figure 5-7: H-3 Rank Order for December 2004 Rank Order 0 10 20 30 40 500 400 r 300 V-200-0. 100 0 i 0@ -100 C 0-200* H-3-Mean Bkg-2-Sig. Bkg+2-Sig. Bkg-Ave. MDC-300 0-400-500 Figure 5-8: H-3 Normality Plot for December 2004 Standard Nonmal Q.antile*1 0 1-4 4 18 Obse-vd DistdbutionI-Norn~aDistibution 12 c 0-282.99 -19937 -115.74 -32.12 51.50 135.13 218.75 302.37 386.00 Concentration (pCi/L)-152 -c19 Figure 5-9: Fe-55 Rank Order for June 2004 Rank Order 5 0 30 20 10-J.0 C°10 c 30-40 7-I ---- ----I* Fe-55 Mean Bkg-2-Sig. Bkg+2-Sig. Bkg--Ave. MDC t r ¶I I-50 Figure 5-10: Fe-55 Normality Plot for June 2004 Standard Normal Quantile-4 2 -1 0 1 2 3 4 2.5 2 1.5 C1 a 4, U.0.5 0-39.18 -35.10 -31.02 -26.93 -22.85 -18.77 -14.68 -10.60 -6.52 Concentration (pCiIL)-153 -C 2-Figure 5-11: Sr-90 Rank Order for December 2004 Rank Order 0 2 1 15 30 45-a aj C C 0 C 0 C.1 0-1 , I ., .I .. I ......... .........II 14f++tfttftt111Ill 111I1Cl11I III 1, 1 1 , 1 1 1 ..'I ' l I* Sr-90 Lim. Mean-2-Sig.+2-Sig.--Ave. MDC-2 Figure 5-12: Sr-90 Normality Plot for December 2004 Standard Normal Q.antilI 1 0 1 4 2 4 16 14 12 1* 10 r28-0.74 -0.52 -0,30 -0 08 0 14 0.36 0.58 0 80 1 02 Co.efntr.tion (pCI/L)-154-CZ)

Figure 5-13: Cm-242 Rank Order for December 2004 0 5 10 15 0.4 0.3 0.2 a°. 0.1 0-0 (D o -0. 1 0 U-0.2 I .II III__ __I+I I I I I I I I I f T H+ i f I ! ! i ! i I I I I I I I I* Cm-242 Lim. Mean-2-Sig.+2-Sig.-',Ave. MDC-0.3-0.4 Rank Order Figure 5-14: Cm-242 Normality Plot for December 2004 Standard Normal Qoantilo 4 2 -1 0 1 2 3 4 e-0.12 -008 -005 .001 002 0.05 0.09 0.12 0.15 Concentration (pCi/L)0-155 -C -rz Figure 5-15: Am-241 Rank Order for December 2004 Rank Order 0 5 10 15 0.5 0.4 0.3 a 0.2 U Q 0.1 0.1 0 a) -0. 1 U U -0.2-0.3-0.4 I I I .I I I I tI 1 t I 1 111 1.. ...l..AI. L..I I + f t T I I I I I I I I I I I 1 ' I I I II* Am-241 Lim. Mean-2-Sig.+2-Sig.--Ave. MDC-0.5 Figure 5-16: Am-241 Normality Plot for December 2004 Standard Normal Quantile-4 2 -1 0 1 2 3 4 12-10 bserved Distnbution NormalI Distnbutionl E-013 -0.09 -0.05 -0.01 0.03 0.07 0.11 0.15 0.19 Concentration (pCiIL)-156-

[ _ flJ9fMW- 1005 MW-101D MW-1035 S'l81o/L 8=5.TugMWM101D3

/H= 275 pCi/L 3H- '258 pCi/L B=324 ug/L Sr-9O NA Sr-90=0. 745 pCi/L 'H= 31000 pCi/L Cs-137= <2.19 pCiML Cs-137- '4.02 pCMlL Sr-90= 3.67 pCiL Total U = 0 g/L Total U= 16.6 ug/L Cs-137= 3.64 pCiL Total U= 27.3 ug/L M 14S B'54 u/'gI A fi 0 A -;S ' ; lPC2E / MW 101SMW13/

_MWS0- p lB=26144 UgIL l C 70.3 ug/L Y MW S904 <H" 286 962L p'i/L 8950 P.L MWiO4 S-137 .~~/ rSO"O=,.938pCUL Sr-SO' 'O.895pCilL WlS____ ' '4.76 pOOL Cs-137' '2.9 pOOL\~~~~~~oa

.= 6oa.7< 0u/L rr//B.268 ,TotaIU=.

L " N SV M -502 'H='314 .Ci.L\ Sr.0 O0962 pCi/L /Cs 137= '41pC/L K6 TotalLI '020 'gIL MW-123 1 DW-1-8134 ug&L. Q '~<'14H266 pCiML Sr-90='0.5 SpCML\ ~~~~~Totrl U=NA .\W MW19 p G /i-BB= 44gg/L.' H='32080pCM/

_.SJ1-900.626 pCM.)___________I_

_ Co-137=7S9pCM1.

ITota U= 0 U=Lu X / < *

  • r Sr-0= 1.9p=i/L626pCMLl 7- ROADS PARNG ARAS. SRFE Cs-137=WAT.E MW-i S.i MONITORING WELL= UNDERLININ D E WL S D =.M C-137'6pC91 rpo).xr.3oXo WITHtU DETECTED \AU POSTED BEO IIN Sr-9O= 0. 06pC 23 p Cs-C13s7=

3.28 pCi/L1 RG E ToIaTRU=:

15.1 C UE PE LR OL TotaL lNOT= DETECM ND NT A Cs537-496pil

°H- 937pi/L t Ioa l- Tota/ U=l OW111 ug/L0 1-8lBUILDIN TgI MAT SUMP l 6lp; i'H-- 1360 p1l 1Bal =7 1.37gI I l Cs-137=<33.26 pCM MICROGRAMS PERlug LIERWE-ICCRISPE0ITRSPU NOTDETECTED:ND~1=99 NOAAYZDN NOSAPLD:S MW-102S B= 1 74 ug/L'H= 12600 pCi/L Sr-90=0 1.3 pCi/M Cs-137='3.97 pCi/I TotalU= 1.56 ug/L/ b 'I IB 240 ug/L'H= 5120 pCiL Sr-90=' O.2 pCiML CS-137=' 3OpCI/L Total U= 9.96 ug/t MWW-1O2S IB=264 u/13H=- 261 PCM s,-so= <0e8S2 pCi/L iCs.137<3.72pCiL

/ l Toia1 U= e 608 ug/L/ I~MW-122S I IB=220 ug/.Ll3H= 621 pCi/L Sr-909= 1.23pCi/Ll Cs-137= OpCMl Totat U= S 529 ug/L MW-1063 B=581 ug/L'H= 1260 pCi/L Sr-90= 7.3pCi/i CS-137= 3. 66 pCiL Total U= 1.27 ogiL gMW-106D 8=85.7 ug/L'H= 2710pCML Sr-90= 02.0 pCi/M Cs-137=' 3.82 pCA Total U= 848 ugh.H' 340 pCMiL 0Sr-SO' .837pCi/L Cs-137=" 3.1 pCi/i.Total U= 0 ug/L'H-272p~i/L

\ ' 3.2 ' \/3oa 'N2 PCi 5'-90 O.62C* r lC-37'2 IL= WELL SCREENED IN UNCONFINESAOUIFEFR N FIGURE 6-1 DISTRIBUTION OF SELECTED SUBSTANCES OF CONCERN AT THE INDUSTRIAL AREA CH 1 I H 5 125 2W5 AND UPPER PENINSULA AREA OF THE CONNECTICUT YANKEE HADDAM NECK PLANT SEPTEMBER 2004=-U~VE IL K WELL SCREENES IN CONFINES AQUIFER Foal 1-IADDA NECK, CTt C 20 ql a~aMO IL L A I HADDAM NECK,0 CT Jefl 1120 C'Z4 OEOF WS I IEOF WS-MW-EOF-2 O 1 B = 65.5 ugiL 3H = <306 pCi/L I% , 4,.N MW-1 000 MW-i 0oS 4 ROADS & PARKING AREAS DIRT ROAD BUILDING SURFACE WATER* SURFACE WATER MONITORING LOCATION O MONITORING WELL MW-123S OB-25 AT-1 i* .MW-124 4 ND= NOT DETECTED N 0 100 200 Feet FIGURE 6-2 DISTRIBUTION OF SELECTED SUBSTANCES OF CONCERN AT THE EOF AND PARKING LOT AREA OF THE HADDAM NECK PLANT SEPTEMBER 2004 HADDAM NECK, CT CH2M HILL\\boomer\H\projects3\CTYankee\MXD\GWMonitoringReport_2 05\SOC EOFParkingLot_9_04.mxd JKelly 3/29/2005 C-zG MW-4 4 MW-3.. .B = 7.95 ug/L 3H = <274 pC/L Sr-90 = NA Cs-137 = < 2.76 pCi/L Total U = NA Well-A*' 8-2* Well-B 9-2 TW-3 MW-13 TW4 TPW-1 4~TPW-2 4 MW-117 B = 71.8 ug/L 3H = < 352 pCi/L Sr-90 = < 1.18 pCi/L Cs-137 = <2.3 pCi/L Total U = NA TW-1 ROADS & PARKING AREAS DIRT ROAD L 0 ::: BUILDING SURFACE WATER 4 MONITORING WELL MW-117 MW-14 N 0 100 200 Feet FIGURE 6-3 DISTRIBUTION OF SELECTED SUBSTANCES OF CONCERN AT THE PENINSULA AREA OF THE HADDAM NECK PLANT SEPTEMBER 2004 HADDAM NECK, CT CH2MHILL\\boomer\H\projects3\CT_Yankee\MXD\GWMonitoringReport_

2 OS\SOCPeninsula_9 04.mxd JKelly 2/22/2005 MW-lOiS 1 144 ugiL MW-103D , DW-1 MW-1 02S 174 ugiL-MW-102D-MW-114S-MW-11i5S MW-1 22D MW-122S 1 220 ug0L MW-1 07D* MAT SUMP SURFACE WATER ROADS & PARKING AREAS B BORON ISOCONCENTRATION LINE DIRT ROAD --(DASHED WHERE INFERRED)I BUILDING " OBSTRUCTION TO GROUNDWATER FLOW MW-lbos MONITORING WELL, UNDERLINING DENOTES WELL SAMPLED 238 ugIL 4 WITH DETECTED VALUE POSTED BELOW LINE MICROGRAMS PER LITER: ug/L NOT ANALYZED:

NA NOT DETECTED:

ND NOT SAMPLED DURING EVENT: NS N A 0 100 200 A _1 Feet FIGURE 6-4 INFERRED DISTRIBUTION OF BORON (ug/L) IN THE UNCONFINED AQUIFER AT THE INDUSTRIAL AREA AND UPPER PENINSULA AREA OF THE HADDAM NECK PLANT SEPTEMBER 2004 HADDAM NECK, CT CH2MHILL\\boomer\H\projects3\CTYankee\MXD\GW MonitoringReport 2_05\Boron UNCONFINED.mxd JKelly 3/10/2005 (( 7271

-505"V-1QOD 25.4 ugiL MW-i 00S I'll MW-loiS MW-103S Fi4.An'MW-i 04S I.,0 MAT SUMP SURFACE WATER ROADS & PARKING AREAS _ BORON ISOCONCENTRATION LINE DIRT ROAD --(DASHED WHERE INFERRED)BUILDING MONITORING WELL, UNDERLINING DENOTES WELL SAMPLED 4 WITH DETECTED VALUE POSTED BELOW LINE PICOCURIES PER LITER: pCi/L NOT DETECTED:

ND NOT ANALYZED:

NA NOT SAMPLED DURING EVENT: NS MWVV 13-s AP4 '-N\ 0 100 200 CH2MHILL A Feet\\boomer\H\projects3\CTYankee\MXD\GW MonitoringReport_2 05\Boron-CONFINED.mxd JKelly 3/29/2005 FIGURE 6-5 INFERRED DISTRIBUTION OF BORON (ug/L) IN THE CONFINED AQUIFER AT THE INDUSTRIAL AREA AND UPPER PENINSULA AREA OF THE HADDAM NECK PLANT SEPTEMBER 2004 HADDAM NECK, CT M~%4 IDI mu §I , EP-165'MWK52~EP-161 MW-1 03S 31000 pCiL-MW-103D MW-1 02S-12600 pCi/L MW-1 02D NI-MW-115S OB-25 t-MW-1 07D MW-107S ND* MAT SUMP SURFACE WATER-ROADS & PARKING AREAS _ TRITIUM ISOCONCENTRATION LINE DIRT ROAD --'(DASHED WHERE INFERRED)I BUILDING OBSTRUCTION TO GROUNDWATER FLOW MONITORING WELL, UNDERLINING DENOTES WELL SAMPLED WITH DETECTED VALUE POSTED BELOW LINE PICOCURIES PER LITER: pCi/L NOT DETECTED:

ND NOT ANALYZED:

NA NOT SAMPLED DURING EVENT: NS N A 0 100 200 CH2MHILL A Feet FIGURE 6-6 INFERRED DISTRIBUTION OF TRITIUM (pCi/L) IN THE UNCONFINED AQUIFER AT THE INDUSTRIAL AREA AND UPPER PENINSULA AREA OF THE HADDAM NECK PLANT SEPTEMBER 2004 HADDAM NECK, CT\\boomer\Hprojects3\CT Yankee\MXD\GW MonitoringReport2o05\Tnbium UNCONFINED 09_04.mxd JKelly 3/30/2005 NW-100D -MW-i 005 4 N X,, -\.>4 1 l g -* MW-103S* MW-1 02S MW-1 02D 5120 pCiL 4, MN-1 04S MW-1 22D.a ND MW-1 22S'&M 7108S* MAT SUMP SURFACE WATER ROADS & PARKING AREAS _ TRITIUM ISOCONCENTRATION LINE DIRT ROAD --(DASHED WHERE INFERRED)BUILDING MONITORING WELL, UNDERLINING DENOTES WELL SAMPLED WITH DETECTED VALUE POSTED BELOW LINE i PER LITER: pCVL NOT ANALYZED:

NA-CTED: ND NOT SAMPLED DURING EVENT: NS PICOCURIES NOT DETE MVWl mwf-N A 0 100 200 A IFeet FIGURE 6-7 INFERRED DISTRIBUTION OF TRITIUM (pCi/L) IN THE CONFINED AQUIFER AT THE INDUSTRIAL AREA AND UPPER PENINSULA AREA OF THE HADDAM NECK PLANT SEPTEMBER 2004 HADDAM NECK, CT EdJ-KflI.1IE I I I\\boomer\H\projects3\CTYankee\MXD\GW MonitoringReport 2_05\Tnbum CONFINED 09 04.mxd JKelly 3/29/2005 Ct3o

-'li iDOD -- , I IJVA/, -X94 /\, EP-165-DW-1 MW-1 02S-- ND MW-i 06S 7.3 pCi/L-MW-i 060* MATSUMP SURFACE WATER-ROADS & PARKING AREAS _ STRONTIUM ISOCONCENTRATION LINE-DIRT ROAD --E (DASHED WHERE INFERRED)= BUILDING [ OBSTRUCTION TO GROUNDWATER FLOW MW-i los MONITORING WELL, UNDERLINING DENOTES WELL SAMPLED 7670 pCI dL4 WITH DETECTED VALUE POSTED BELOW LINE PICOCURIES PER LITER: pCVL NOT ANALYZED:

NA NOT DETECTED:

ND NOT SAMPLED DURING EVENT: NS N 0 125 250 CH2MHILL A feeMM:== et INFERRED DISTRIBUTION OF STRONTIUM-90 (pCi/L) IN THE UNCONFINED AQUIFER AT THE INDUSTRIAL AREA AND UPPER PENINSULA AREA OF THE HADDAM NECK PLANT SEPTEMBER 2004 HADDAM NECK, CT\\boorer\H~projects3\CT~_Yankee\MXD\G\_MonitoringReport2_0S~r-90UNCONFINED_09_04.mxd MJKelly 3/30/2005

~I% -101 as MW-101D ,-ND MW-1t MW-103S MW, 04S I -!~-08S 0 MAT SUMP SURFACE WATER-ROADS & PARKING AREAS S STRONTIUM ISOCONCENTRATION LINE DIRT ROAD --(DASHED WHERE INFERRED)BUILDING " OBSTRUCTION TO GROUNDWATER FLOW MONITORING WELL, UNDERLINING DENOTES WELL SAMPLED WITH DETECTED VALUE POSTED BELOW LINE PICOCURIES PER LITER: pCi/L NOT DETECTED:

ND NOT ANALYZED:

NA NOT SAMPLED DURING EVENT: NS N CH2MHILL A o FIGURE 6-9 INFERRED DISTRIBUTION OF STRONTIUM-90 (pCi/L) IN THE CONFINED AQUIFER 500 AT THE INDUSTRIAL AREA AND UPPER PENINSULA AREA OF THE HADDAM NECK PLANT SEPTEMBER 2004 J Feet HADDAM NECK, CT 250\fboomer\H\projects3\CTYankee\MXD\GW MonitoringReport2_05\Sr-90 CONFINED_09_04.mxd JKelly 3/30/2005 C3z-(/ H-0l*MW-1005 MW-101D l EP 165MW13/ H= 3545pCilL L H= '359 pCM L 3H= 988 PCI/L B=- 57.4 ugL M9WC12 Sr-9O NA Jv Sr-90'0937pCVIL Sr-90=<0.768pCi/L

-H= l0800pQ1L B-47 ug/L Cs-17 <47pCL\ s7=0 <s i~l fC-137=<55pCVLl,.-13 Sr-90= < 1.0 pCVL 'H= 81930 pCi/L.TbtalU= <020ugLS Total U= 22 4ug/L l\ TotalU= 243ugL / S/ Cs-137=<.3.6pCM l Sr-90=<~1, 13 pCI/L< M-01\ I// TotalU= 6 76 ug>L Cs-137=<2.19pCi/L

_l MW-OO \ I EP-166 TotalM U= 9. 79 uglL*H B=12//3W-05

\IB157ug/L///

MW-102D 303 Sr-90=<0es73PQL

'H Ttt= 6480 PQIL A~1 Cs-137= 6<1 3~l 399~~_3 pCVLL MA I x /Toa U=O5.29 uglL ICs /M-122D514Q Bnl g u ToaU 105v B =2 2 U9/LI 3 1-/=2883pQIL IEC ¢ 5s-13=< .8257pCMlsr90 lS0.8623pVL pSil _Yt1U 0 ,80td= 7SugL\l~~~~~~C5-137=

3-39pCilLl 3lW14EM-5SM-25 Total/=N I = IB349LIa 3 N 20S Ig B=167u/LD MW l 'H= 9040pCM /t 7v3=50pV IAT- 13 lS-00.5pVLr/L Sr-90=<0.8256pi/Ll l3H535699PCVLL

< Cs-t37= <448CL .W55> _Cs13-5pCL4 IC&-137='3787pClLI

  • __ lMW-122S T1a 9 I4 IVKf-A-___I B=802 ug/LlB=25 COIL 's\X-- H= 4570pCVLlB=2uI lCs-137=<5448pCiL 7s13= 5.25\pB=14U9L S Sr-90=<69PV I 0. 85 pilI=67L IMIW-108SI

/ Cs-l37= e3 1pMI,, H28pQiL/\13H 9iL Jl lTetJU= Q5 U9/L I \ IMW110D I \ I Sr-90=<69i/

B .R 1569= 0pClLI'H 96 MW19 Cs310u137 zs-37<4.30i8p I~-17=66tiL_

BTe98.5 ug95g/L ToaU llM-105ugJ IL Cs-1 H= 3Hs39 pVL ss--137=0.919pCVL IL MW-12 Totls-137=<420PCI/LL B 12 uqVL 8=308~ Igl 1B=45 13670 p 60iCM'H=Cr#LE O8OIOIGWL6NELNIGEOEWELAPE1 p3H='36SrC90L I .15240= 103PVL 4/J7 SXtP90= 3.08ETDALEOTDEOW}Ellr90<

5C/ pQ1 Cs CS37= 37=658pCV Is 137-130.3.146k3p'H=L287_,QI MICRGRAM LI= 9ITER ug/L PICOCURIE PER0 LITER: 3C;/L I9p B= 13 ugL C-137~3.3pQI 90~~ O 812p ~)NOT 3900TE NDV Tota ANLYED 0NA NOTL SAMLED NS7= 6I ~= WELLSCREENED IN UNCONFINEDAQUIFER N FIGURE 6-10 DISTRIBUTION OF SELECTED SUBSTANCES OF CONCERN AT THE INDUSTRIAL AREA_ _D_125 250 AND UPPER PENINSULA AREA OF THE CONNECTICUT YANKEE HADDAM NECK PLANT DECEMBER 2004 C H 2MH ILL =j WELL SCREENED IN CONFINED AQUIFER A Feet HADDAM NECK, CT b eW~reoectsEICT YVk-eeMXDSAW Mor-mnng Repon_2U0SSOC1 042md -JK1ly3/10Q5 4 EOF WS.Y 4EQFWS MW-EOF-2 ' 6' E0F-l B = 85.6 ug/L \ , 3 H =<344 pCKL LMW-I oo0E MW-i o0Ss-ROADS & PARKING AREAS DIRT ROAD r BUILDING SURFACE WATER" 08B-2,5 AT-1iz+S MW-124* SURFACE WATER MONITORING LOCATION 4 MONITORING WELL MW-1 23S N A 0 100 200 A Il1 ~ IFeet FIGURE 6-11 DISTRIBUTION OF SELECTED SUBSTANCES OF CONCERN AT THE EOF AND PARKING LOT AREA OF THE HADDAM NECK PLANT DECEMBER 2004 HADDAM NECK, CT C~.111112 mIEWI I 1 ..XXboomer\H\projects3\CTYankee\MXD\GW MonitoringReport 2O5\SOCEOF ParkingLot 12 04.mxd JKeIly 3/30/2005 Well-A*-~ 8-2' -Well-B 9-2 TW-3*MW-13 TWX TPW-1 4o TPW-2 4 TW-1 ROADS & PARKING AREAS DIRT ROAD--- BUILDING MW-14 4ai SURFACE WATER' I MW-1 17 MONITORING WELL N 0 100 200 Feet FIGURE 6-12 DISTRIBUTION OF SELECTED SUBSTANCES OF CONCERN AT THE PENINSULA AREA OF THE HADDAM NECK PLANT DECEMBER 2004 HADDAM NECK, CT CH2MHILL\\boomer\H\projects3\CTYankee\MXD\GWMonitoringReport_2o05\SOC_Peninsula_12 04.mxd JKelly 2/24/2005 OUTLINE OF THE INDEPENDANT l /-I FUEL STOAAGEINSTALLA TION ROADS & PARKING AREAS SURFACE WATER I IBUILDING MW-208 B=200 ugiL Sr-90 9.891pCilL 4 MONITORING WELL, UNDERLINING DENOTES WELL SAMPLED Cs-13709.88pCUL WITH DETECTED VALUE POSTED BELOW LINE MICROGRAMS PER LITER: ug/L NOT DETECTED:

ND I PICOCURIES PER LITER: pCi/L NJOT ANALYZED:

NA NOT SAMPLED: NS N CH2MHILL A-FIGURE 6-13 DISTRIBUTION OF SELECTED SUBSTANCES OF CONCERN AT THE LANDFILL AREA OF THE CONNECTICUT YANKEE HADDAM NECK PLANT DECEMBER 2004 HADDAM NECK, CT 0 125 250_ = Feet\fboomer\H\projects3\CTYankee\MXD\GW Monitoring Report 4 2004\SOC Landfill_12_04.mxd JKelly 3/8/2005 C3&'

EP-1 71 364 ug/L EP-1 66 157 ugiL MW-122D-MW-1 07D MW-1 07S 189 ugIL 103 uglL* MAT SUMP SURFACE WATER-ROADS & PARKING AREAS BORON ISOCONCENTRATION LINE DIRT ROAD --(DASHED WHERE INFERRED)BUILDING MONITORING WELL, UNDERLINING DENOTES WELL SAMPLED l WITH DETECTED VALUE POSTED BELOW LINE MICROGRAMS PER LITER: ug/L NOT DETECTED:

ND NOT ANALYZED:

NA NOT SAMPLED DURING EVENT: NS N A 0 100 200 Feet FIGURE 6-14 INFERRED DISTRIBUTION OF BORON (ug/L) IN THE UNCONFINED AQUIFER AT THE INDUSTRIAL AREA AND UPPER PENINSULA AREA OF THE HADDAM NECK PLANT DECEMBER 2004 HADDAM NECK, CT C!H21IHILL

\\boomer\H\projects3\CT Yankee\MXD\GW MonitoringReport2O05\Boron UNCONFINED_12_04.mxd JKelly 3/29/2005 MW-1 00D A.4 I n, A MW-101D/ 56.4 ugiL MW-lOlS A.., /MW-1 03S MW-102S MW-122D 92.2 ugiL 4mW-i08S* MAT SUMP SURFACE WATER ROADS & PARKING AREAS BORON ISOCONCENTRATION LINE DIRT ROAD -No (DASHED WHERE INFERRED)I BUILDING MvW-UbU MONITORING WELL, UNDERLINING DENOTES WELL SAMPLED 59.1 ugiL 4 WITH DETECTED VALUE POSTED BELOW LINE PICOCURIES PER LITER: pCi/L NOT ANALYZED:

NA NOT DETECTED:

ND NOT SAMPLED DURING EVENT: NS N A 0 100 200 A Feet INFERRED DISTRIBUTION OF BORON (ug/L) IN THE CONFINED AQUIFER AT THE INDUSTRIAL AREA AND UPPER PENINSULA AREA OF THE HADDAM NECK PLANT DECEMBER 2004 HADDAM NECK, CT lf"-1&%MIl411 I lawwo MANNNEWINg ONE-E..\\boomer\H\projects3\CTYankee\MXD\GW Monitonng Report 2 05\BoronCONFINED_12 04.mxd JKelly 3/29/2005 c ?q 3)

N k 0 100 200 A Feet FIGURE 6-16 INFERRED DISTRIBUTION OF TRITIUM (pCi/L) IN THE UNCONFINED AQUIFER AT THE INDUSTRIAL AREA AND UPPER PENINSULA AREA OF THE HADDAM NECK PLANT DECEMBER 2004 HADDAM NECK, CT E~u~uEuuIIII As _ l l l __-Hl.~-CT .,kWXDGW -WTliu-UNONFNED12 -JKeIly W-5'00 c-1

.,K MW-50'5.14_ ND EP-165 ,, 'r ,%>+' X X W-100D ;i'N50 z>. .><,$Q MW-100S -/\..<l

  • _50t >/-0 S t ND ND t<~~~ \A"-MW-i101 D>-ND I,$MW-ilbS MW-1 02D 6480 pCi/L MW 104S 3SM MW-122D 610 pCi/L-MW-122S MW-1 07D ND-* AW-108S* MAT SUMP SURFACE WATER ROADS & PARKING AREAS _ TRITIUM ISOCONCENTRATION LINE DIRT ROAD --(DASHED WHERE INFERRED)BUILDING MONITORING WELL, UNDERLINING DENOTES WELL SAMPLED WITH DETECTED VALUE POSTED BELOW LINE PICOCURIES PER LITER: pCi/L NOT DETECTED:

ND NOT ANALYZED:

NA NOT SAMPLED DURING EVENT: NS MW-1 12S N i\ 0 100 200 CHZMHILL A = Feet FIGURE 6-17 INFERRED DISTRIBUTION OF TRITIUM (pCi/L) IN THE CONFINED AQUIFER AT THE INDUSTRIAL AREA AND UPPER PENINSULA AREA OF THE HADDAM NECK PLANT DECEMBER 2004 HADDAM NECK, CT\\boomer\H\projects3\CT Yankee\MXD\GW MonitoringReport_2_05\Tnbum CONFINED_12 04.mxd JKelly 3/3012005 MW-1 00D MW-100S NA EP-166 ND MW- 103S NS MW-103D MAT SUMP 2.43 PCI/L'a:* MAT SUMP SURFACE WATER--- ROADS & PARKING AREAS SSTRONTIUM ISOCONCENTRATION LINE DIRT ROAD --(DASHED WHERE INFERRED)I BUILDING OBSTRUCTION TO GROUNDWATER FLOW MONITORING WELL, UNDERLINING DENOTES WELL SAMPLED-4 WITH DETECTED VALUE POSTED BELOW LINE PICOCURIES PER LITER: pCi/L NOT DETECTED:

ND NOT ANALYZED:

NA NOT SAMPLED DURING EVENT: NS N A 0 50 100 200 A Feet FIGURE 6-18 INFERRED DISTRIBUTION OF STRONTIUM-90 (pCi/L) IN THE UNCONFINED AQUIFER AT THE INDUSTRIAL AREA AND UPPER PENINSULA AREA OF THE HADDAM NECK PLANT DECEMBER 2004 HADDAM NECK. CT f~EJ~KAI-II

_- -An_-. ..__\\boomerhH\projects3\CTYankee\MXD\GW MonitoringReport_2_05\Sr-90_UNCONFINED 12 04.mxd JKelly 3/29/2005 1

MW4IO0D'>~ NA "-;K MW-1600-s EP-165/ EP-1 66 X MW-103S MW-101D 115$* MW-102S MW-1 02D ND I 01-25 i MAT sMP 2 .43 pCih U MW-i 220 2/ ND X MW-122S I/ MW-i 07S 4,e 7D 4> 7 MW- 1 08S* MAT SUMP ROADS & PARKING AREAS DIRT ROAD BUILDING SURFACE WATER MW-lbs MONITORING WELL, UNDERLINING DENOTES WELL SAMPLED ND 4 WITH DETECTED VALUE POSTED BELOW LINE PICOCURIES PER LITER: pCi/L NOT ANALYZED:

NA NOT DETECTED:

ND NOT SAMPLED DURING EVENT: NS N CH42MIHILLA 0 FIGURE 6-19 INFERRED DISTRIBUTION OF STRONTIUM-90 (pCi/L) IN THE CONFINED AQUIFER 500 AT THE INDUSTRIAL AREA AND UPPER PENINSULA AREA OF THE HADDAM NECK PLANT DECEMBER 2004 J Feet HADDAM NECK, CT 250\\boomer\H\projects3\CTYankee\MXD\GW MonitoringReporL2_05\Sr-90 CONFINED_12_04.mxd JKelly 3/30/2005 Figure 6-20: Radar Plot of Geochemistry for Landfill Area Monitoring Wells Ca 1 .0<CI Mg I. -4MW 203 PVC l41- MW 208 PVC MW 201 PVC l BMW 207 PVC-l-/ MW 200 PVC-'-MW 205 PVC S04 K +Na C03 + HCO3-176-Figure 6-21: Radar Plot of Geochemistry for Upgradient Monitoring Wells in the Industrial Area Ca CI S04 Mg 4 MW-101D-04 0 U MW-101S-04 0 MW 100S-04 XMW111S-03U AMW 100D-04 0 MW 112S-03 U K + Na C03 + HCO3-177-C. 4rfi Figure 6-22: Radar Plot of Geochemistry for Downgradient Monitoring Wells in the Industrial Area Ca 9.0, CI S04 Mg 0 0 MW 122S-04 MW 109S-04-MW 107S-04 ZMW 110S-04 K+ Na C03 + HCO3-178 -c ri Figure 6-23: Radar Plot of Geochemistry for Shallow Monitoring Wells in the Industrial Area Ca cl) Mg.00/MW 104-04-4'-MW 107S-04/MW 109S-04/MW 106S-04 S04 K + Na C03 + HCO3-179-C 19 Figure 6-24: Radar Plot of Geochemistry for Deep Monitoring Wells in the Industrial Area Ca C~ ~~~ 03 00X cI Mg mW 101I MW 106+MW 107< t X \ *MW 109-40-mw m0 S04 K +Na C03 + HCO3-180-I1D-04 MD-04 10-04 10-04 C q -

Figure 6-25: Boron Site-wide Concentration Box Plot 100000 Do 10000 I e,'6 To I I eb e 1000 K aR o 4100 Ilb 100 10 11 be "I ,S Dec-98 Ju-99 Dec-99 Jcn-00 Dec-00 Jun-01 Dec01 Jec-02 Dec-02 Jun-03 Dec-03 Jcn-04 Dec-04 Tim.'Figure 6-26: Box Plot of Gross Alpha Concentrations in Unconfined Aquifer 20 r 15-j j3 10 0.5 0 as 5-Maximum-75th %-Gross Alpha Median-25th %-Minimum-EPA MCL-- CRDL Mean MDC TI T 4 ~ I I z IIt --I--_ 1 F -I -_o 1*--a 1-le 11 -.6-5 100S 101S 102S 103S 104S 105S 106S 107S 108 109S 110S 111S 112S 113S 114S 115S 117S 122S 124 125 Well ID-181 -C4Q Figure 6-27: Box Plot of Gross Alpha Concentrations in Confined Aquifier 25r --- ------- ---- ---------

..I .20 15-J C., 0r 10 C E vE C 0 0 5 0-5 100 10 1 (1+ ' T_ A 7 I _ 5111 now T 00_-Maximum_ -75th %-Gross Alpha Median I -25th %i -Minimum-EPAMCL--CRDL t Mean MDC 100D 101D 102D 103D 105D 106D 107D 109D 110D 122D 123 Well ID Figure 6-28: Gross Alpha Site-wide Concentration Box Plot-24.1 21.5-16 2 7 17 2 1- 5 1.354 1 , 7 3 1 00947 3 0459 -0455 0.577 I 0.1 _ 0.73-0.55'1

-40.8-28.8-3 88 r 2 7 3-1 016 3-09832-15.7-50-1.08 0.1 Dec-01 Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sep-04 Dec-04 Time-182-Figure 6-29: Box Plot of Gross Beta Concentrations in Unconfined Aquifer 100 ___________

90 80-Maximum 70 -75th %,- Gross Beta b 60 Median-25th %0 , 50- _ -Minimum-EPA MCL C40 CRDL Mean MDC 30 20 I 10 oS Well ID Figure 6-30: Box Plot of Gross Beta Concentrations in Confined Aquifer 60 ____-_50-Maximum 40 -75th %, Gross Beta bw Median-25th %0 30- -Minimum e, -EPA MCL o CRDL 20 Mean MDC 10 __ ___ _ _ _ __ -___ __ __0 100D 1010 102D 103D 105D 106D 107D 109D 110D 122D 123 Well ID-183-c5c2 Figure 6-31: Gross Beta Site-wide Concentration Box Plot 1000-490.1 J 801 297-226 -242 -240-253-180 -1599-192 100-44.3 -47.6 -3, 2y a.10 4615 p 6; -t 10 03 5.-2.19 -.9 -233 18 -216 -2,02_ 1 -7.16 -091 1.5 9 ~,56 6.21 t-..I ---1.62 1.31-1 31-1.33 -1.37-0.788 0.1 De-01 Me-02 Jc-02 Sep-02 De-02 Me.-03 Jc-03 Sep-03 De-03 Mr-04 Je-04 Sep-04 De-04 Tie..Figure 6-32: H-3 Concentration Trend at Cluster Well MW102 35000 30000 25000 28630-0-DMW102D H-3 Conc.-EPA MCL (20000 p~il)____ RDL (400 pCi/L)--- Mean MDC (285.7 p~il)* MW102S H-3 Conc.-j 0 I 00 UC 20000 15000 12600 10000 4880 5000 4 2370 1100 , +. 770 0-5000 i Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sep-04 Dec-04 Sample Event-184 -C, I Figure 6-33: H-3 Concentration Trend at Cluster Well MW103 35000 30000 25000 20000 15000 10000-j U0 C 0 U 5000 0-5000 i Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sep-04 Dec-04 Sample Event Figure 6-34: H-3 Concentration Trend at Cluster Well MW110 25000 20000 15000 10000 5000 U aC.r-0 C 0 ,o 0-5000 I Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sep-04 Dec-04 Sample Event-185 -C5-2 Figure 6-35: H-3 Concentration Trend at Cluster Well MW105 25000 r 20000--MW105D H-3 Conc.: EPA MCL (20000 pCi/L)I RDL (400 pCi/L)---Mean MDC (276.3 pCi/L)* MW105S H-3 Conc.15000 C-0 a 0 C 0 CI, 10000 F 5000 7860 8070 5410 5520 ,. "-,414 4470 4850+ .*- 3370.- 3350 1 60 2390 +854 05 140 ~ 1280 0-5000 Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sep-04 Dec-04 Sample Event Figure 6-36: H-3 Concentration Trend at Well MW114S 10000 9000 8000 7000 -6000 5000 4000 -* MW-114S H-3 Conc.EPA MCL (20000 pCi/L)_ RDL (400 pCi/L)---Mean MDC (285.7 pCVL)6730 C.)C 0 0I-S+ 3730 3000 2000 1000+ 153 If 1140 + 1190+927 t 1070.+1280 -1350-#A, A 0 , Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sample Event-186-Figure 6-37: Box Plot of H-3 Concentrations in Unconfined Aquifer 25000 r 20000 t 15000-J CL 0 10000 C 0 0 5000 0-Maximum-75th %-H-3 Median-25th %-Minimum-EPA MCL--CRDL Mean MDC----7_ _ _a 4 '-5000 1\0°§~~r 000 1s N p Al0@ 60S# 0pN 'll 'll I I ~ N \N Well ID Figure 6-38: Box Plot of H-3 Concentrations in Confined Aquifer 35000 r 30000 t 25000= 20000-C 0 0 15000 000-Maximum-75th %-H-3 Median-25th %-Minimum-EPA MCL-CRDL Mean MDC 4 5000.._ ...,_ -o +---5000 -100D 1010 102D 103D 105D 106D Well ID 107D 109D 110D 122D 123-187 -C5L Figure 6-39: H-3 Site-wide Concentration Box Plot 1000000 e4°°100000 I-@00 -00 10000 -: 200 ~~- --I -MenMC(. i/)19 soL I.o~~ 106.2-1500 4-MW-105S Sr-go Conc,-___EPA MCL (8 pCi/L)___RDL (2 pQiIL)200 --Mean MDC (0.8 p~il)19 j19 150* I 138 o 83> 91.8 50 427.6* 162 0 _Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sample Event-188 -

Figure 6-41: Sr-90 Concentration Trend at Cluster Well MW106 25 r 20 18 68 4-MW106D Sr-90 Conc.-EPA MCL (8 pCi/L)_ RDL (2 pCi/L)---Mean MDC (0.8 pCi/L)* MW106S Sr-90 Conc.15:r 0.L C 0° 10 C 0 5 13 ,t 5/9 5 8.,5 I 317 + - ------1 -- 0 2 0).215 -0.0942 0.148 0.88 032 0~3 09 52 0.325 059 0.226 0.218 0-5 Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sep-04 Dec-04 Sample Event Figure 6-42: Sr-90 Concentration Trend at Cluster Well MW103 20 r 15 1 .3 MW-103S Sr-90 Conc.-EPA MCL (8 pCi/L)RDL (2 pCi/L)---Mean MDC (1.0 pCi/L)-* MW-103D Sr-90 Conc.0 0.-0 0I U 10 5 b.1\ n i 2.59 2.27--_ 13. I .-X 1 0+ 0 O. .t 4. 42 -0.24 0.176 0.337 1 .4 +-0.24----1.26 0.437 0.372 _017,56-5 L Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sep-04 Sample Event-189-Figure 6-43: Sr-90 Concentration Trend at Well MW104S 9 8 7-6:r 5 a C 4 l 3-C 0C o 2 1 -1+ MW104S Sr-9O Conc.EPA MCL (8 pCi/L)-RDL (2 pCi/L)---Mean MDC (0.9 pCi/L)I 314 1+ t:86r+-0.0046+ 0.0679 +}0.215 + 0.166-2 Jun-03 Sep-03 Dec-03 Mar-04 Sample Event Jun-04 Sep-04 Dec-04 Figure 6-44: Box Plot of Sr-90 Concentrations in Unconfined Aquifer 250 T 200 150-j U 0r 0 C 0 0 50 0 7-Maximum-75th %-Sr-90 Median-25th %-Minimum-EPA MCL-CRDL Mean MDC---bU-,,'. 6e 4¢ op Qp 40 6S Qp Ne *S 4 a " " " 8W $Well ID-190 -

Figure 6-45: Box Plot of Sr-90 in Unconfined Aquifer (Expanded View)20 -18 16 14 -2 12 -O rA a.0 10 0 6-Maximum-75th %-Sr-90 Median-25th %-Minimum-EPA MCL-CRDL Mean MDC I 2-! 2 -I 4_----- g.........

T-2 1OOS 101S 102S 103S 104S 105S 106S 107S 108 109S 110S 111S 112S 113S 114S 115S 117S 122S 124 125 Well ID Figure 6-46: Box Plot of Sr-90 Concentrations in Confined Aquifer 5 4 3.e2 U a.C 0% 2 1 C 0 0-Maximum-75th %Sr-90 Median I -25th %-Minimum-EPA MCL CRDL_ , Mean MDC.j-T*I_i~ " m1_ -I+ -_ -_-1 100D 101D 102D 103D 105D 106D Well ID 107D 109D 110D 122D 123-191 -

Figure 6-47: Sr-90 Site-wide Concentration Box Plot 1000.00 F 100.00 143 I 69.7 122 116 181.6 138 -101 83.3 197 139 91.8 We S I=e Q1 16.2 10.00-4.58 _3.85 -3.83 0.37 0.34 8.56 73 T 4-1.0-1.41_085 1.08 I 0.71 0.32 0.33-1.21 -1 11 g m@0.6955T ~ 0.013+0.910 0.588 -0.373 0.381 0.452 0.207 0.10 Mar-01 Jun-01 Sep-01 Dec-01 Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sep-04 Dec-04 Tlme Figure 6-48: Cs-137 Concentration Trend at Cluster Well MW103 225 200 175 150-J a 0 c a I0 w 125 100 75-O--MW-103S Cs-137 Conc.-EPA MCL (200 pCUL)RDL (15 pCi/L)Mean MDC (5.3 pCi/L)* MW-103D Cs-137 Conc.22.4 50 25-25 1 Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sep-04 Sample Event-192 -Ccsq Figure 6-49: Cs-137 Concentration Trend at Well MW115S 20* MW-115S Cs-137 Conc.EPA MCL (200 pCi/L)15 RDL (15 pCi/L)---Mean MDC (5.5 pCi/L)15 10 q..° 3 138 115 372 0'5 10 36 I 28-5_Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sep-04 w Sample Event Figure 6-50: Cs-137 Concentration Trend at Cluster Well MW102 40 .- _ __ ._ ...........

_ _ ..._ .__ __ __._._ ...__35 MW02 Cs-137 Conc.EPA MCL (200 pCi/L)30 RDL (15 pCi/L)----Mean MDC (4.6 pCi/L) 212 25 -* MW102S Cs-137 Conc..257 2.8 CL 0 j 5_Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sep-04 Dc0_ Sample Event 4 0 1---3 .5 4 l,-M12DCs13 4 on.- 8 30 RDL (1.4p 2.6-5-10 Ma-0 Jun-2 Se-02 ec-0 Mar03-Jn-0 Se-3 Dc0 a-04 Ju-0 Se-0 ec0 Sapl Een-193 -

Figure 6-51: Box Plot of Cs-137 Concentrations in Unconfined Aquifer 100 r 90 80 +70 a 60 c 50.2 c 40 C 0C U 30 t-Maximum-75th%-Cs-137 Median-25th %-Minimum-EPA MCL CRDL Mean MDC I+20 4 10 t 0 T.f 4 Z S a ----_-- i a.@4 -a. Of-10 _111' Nle K01 6 p p 60e e 60S ` g 4 4 " 1 A p

  • e Well ID Figure 6-52: Box Plot of Cs-137 Concentrations in Confined Aquifer 20 r 15 a U.o 0 ID 0 U 10 5 0-Maximum-75th %-Cs-1 37 Median-25th %-Minimum-EPA MCL--CRDL Mean MDC 01111111111 4T+7 -I I-5-10 100D 101D 102D 103D 105D 106D 107D 109D 110D 122D 123 Well ID-194 -Cf-P Figure 6-53: Box Plot of Am-241 Concentrations in Unconfined Aquifer 0.6 r 0.5 0.4 +/-: 0.3 0 CL 0 2 V 0.2 0.1 t I-Maximum-75th %-Am-241 Median-25th %-Minimum I -EPA MCL-CRDL Mean MDC_ i J-0.1 1-0 .2 Well ID Figure 6-54: Box Plot of Am-241 Concentration in Confined Aquifer 0.8 r 0.7 0.6 0.5 +cJ 0.4+-0.C r- 0.2 0 O i -Maximum-75th %-Am-241 I Median-25th %-Minimum-EPA MCL CRDL j Mean MDC in i 0.1 0-0.1-0.2.0. 1_~ _1_6~I T 1OOD 101D 102D 103D 105D 106D Well ID 107D 109D 110D 122D 123-195 -C(PZ Figure 6-55: Sr-901Y-90

+ Cs-137 versus Gross Beta Gross Beta Correlation y = 0.8807x 2 =R =0.9289 500 450 400 350 I, 300.250 si 200 150 100 50 0.., \ --.I .I ..-.._ _ _ -_ ....._ ....._ ._ .-..I ... .. ..so 100 150 200 250 300 350 400 450 Soo Gross Beta Concentraton (pCULl Figure 6-56: Total Uranium vs Gross Alpha Ca;l--tArl

  • !:4glr4-Se r -P- R< i W W~Dept. Review: Signature:

-9 f -o 0ate: Nuclear Safety Review: Signature:

/ Date:..--: t -ACP 1.2-6.24 Original SEP 2 9 2003 Connecticut Yankee Decommissioning Project 24265-000-GPP-GGGR-R5300-003 Rev. CY-001 Health Physics Procedure Page I of 24 I'J 1.0 OBJECTIVE To describe the methods for measurement of ground water levels and collection of representative samples of ground water from monitoring wells.2.0 REQUISITES Representative samples of ground water must be collected from monitoring wells and analyzed in order to demonstrate compliance as described in the Ground Water Monitoring Programn (GWMP) and to meet the requirements of the License Termination Plan, Revision 1, August, 2002.3.0 INSTRUCTIONS 3.1 Equipment and Materials 3.1.1 IF performing synoptic, or individual, water level monitoring, THEN OBTAIN the following equipment, as necessary:

  • map of well and surface water gauging locations* key(s) for all well locks* 9/16", or V2" socket with drive for removing curb box covers* sampling procedure, field log book and/or forms for documenting data and comments (Attachment A)* electronic water level meter* clean cloth or paper towels* polyethylene sheet* one gallon of de-ionized or distilled water, or spray bottle containing such* garbage bag for trash 3.1.2 IF performing water sampling, THEN OBTAIN the following equipment, as necessary:
  • map of well and surface water gauging locations* key(s) for all well locks* polyethylene sheet* 9/16", or 'A" socket with drive for removing curb box covers* sampling procedure, field log book and/or forms for documenting data and comments (Attachment B)* stainless steel, polyethylene or Teflon bailer (one per well)

SEP 2 9 2003 Connecticut Yankee Decommissioning Project 24265-000-GPP-GGGR-R5300-003 Rev. CY-OOI Health Physics Procedure Page 2 of 24.variable speed electric drill with pump attachment, peristaltic pump, bladder pump, and/or submersible pump* portable generator and extension cord and/or 12 VDC car or marine battery Air compressor or nitrogen gas (for use with bladder pump)* nylon string (enough for the total depth of well(s) to be sampled)* de-ionized or distilled water* electronic water.level meter.-.* clean cloth or paper towels* sample bottles -one set per well sample labels* trip blank (water sample issued from the volatile organic compound (VOC) analytical lab) for VOC analysis, if required* custody seals* preservatives, if required (see Attachment C).containers to hold the purged ground water* cooler(s) with "blue ice" packs for storing samples, if sample cooling is required decontamination supplies(e.g., non-phosphate detergent, tubes, etc.)* packing materials* leather work gloves.zip-lock bags* latex, and/or nitrile gloves -two pairs per well indelible marker (Sharpie or equivalent) garbage bag for trash.roll of aluminum foil.pump tubing (1/4 to 3/8-inch ID)silica tubing (1/8-inch ID;for use with peristaltic pump)hose clamps.15/16" socket with drive if using 55 gallon drums for containing purge water* knife or scissors, measuring container* individual pH, temperature, conductivity and turbidity meters or an Horiba, or equivalent, combination meter, if necessary 0.45 micron ground water filters (one per well if sampling for dissolved metals).chain (s)-of-custody flow-through-cell for field parameter measurements, if necessary.

ij i.

...-L Connecticut Yankee Decommissioning Project Health Physics Procedure SEP 2 9 2003 24265-000-GPP-GGGR-R5300-003 Rev. CY-001 Page 3 of 24 , NOTE Peristaltic pumps shall not be used when collecting samples for VOCs analysis.Peristaltic pumps also have limited lift capacity and are ineffective where the depth to water exceeds 20 feet.3.2 Connecticut River Level Determination NOTE Because the Connecticut River water level fluctuates with the tides, obtain a water level from the boat dock ramp reference location at the time of synoptic ground water level measurements.

3.2.1 OBTAIN the surface water level of the Connecticut River, by the designated elevation benchmark whenever water level measurements are taken in association with synoptic measurements.

a. Connecticut River benchmark is located on the south side of the boardwalk leading to the dock adjacent to the Information Center.b. Synoptic water level measurements are recorded on Attachment A.3.3 Synoptic Measurements of Depth to Ground Water Surface 3.3.1 OBSERVE the area surrounding the well and the well itself and NOTE the existence of any unusual conditions, e.g., ground staining from possible oil or gasoline spills or damage to the well.3.3.2 IF any unusual condition exists, DO NOT proceed with that well.a DESCRIBE the condition(s) in the comments section of Attachment A.* NOTIFY Final Status Survey supervision.

3.3.3 CONTINUE if no unusual conditions exist.I\--I-NOTE Personnel performing sampling should exercise caution to prevent cross-contamination whenever the potential for coming into contact with ground water exists (i.e., well purging, sample collection).

Connecticut Yankee Decommissioning Project Health Physics Procedure

.SEP 2 9 2003 24265-000-GPP-GGGR-R5300-003 Rev. CY-001 Page 4 of 24 CAUTION'-Due to fluctuation of hydraulic gradients, the air inside the well may have become pressurized.

Approximately two hours before sampling or ground water level measurements are to take place, loosen the applicable well caps to relieve any built up pressure.

Exercise caution when removing well covers.i3.3.4 OPEN the well cover and UNCAP the monitoring well, exercising care not to introduce any foreign material into the well. Note any unusual odors, sounds or. difficulty opening the well.; If thfewellhead is submerged with water, remove standing water from within the curb box to a level below the top of the'well.

Put' removed w'ater into a container if required.Record observations on the Synoptic Water Level Measurement Data Sheet (Attachment A) or Ground Water Monitoring Well Data Log provided in Attachment B, as appropriate.

3.3.5 TURN the electric water level meter on and test the operational status by either placing the end of the probe in clean water or by use of the probe test system. .NOTE The measurement should be taken at the' notch'filed on the top of the PVC pipe.The notch may or may not also be marked with an indelible marker.3.3.6 Slowly LOWER the probe intb the well and CONTINUE lowering until'the tone 'sounrd indicates that contact with the water has been achieved.3.3.7 REPEAT raising and lowering the probe via the cable using slight movements and keeping your head and face away from the well head, while listening to the indicator, until the water level surface in the well can be determined to the nearest 0.01 feet from the top of the PVC riser.3.3.8 RECORD the well number, depth to ground water surface; and the start and finish times if synoptic measurements were taken on Attachment A.3.3.9 As the cable is withdrawn from the well, WIPE down the cable and probe using a clean damp cloth, or paper towel(s).

Connecticut Yankee Decommissioning Project Health Physics Procedure SEP 2 9 2003 24265-000-GPP-GGGR-R5300-003 Rev. CY-OO0 Page 5 of 24 NOTE The well shall not be sampled if any liquid, other than water, is present on the water level meter probe. A note of the condition shall be made on Attachment A and the well shall be closed and locked. The probe shall not be used again until it is decontaminated.

3.3 .10 PLACE the probe into the probe holder of the meter to prevent it from becoming contaminated.

At no time shall the probe and/or cable come in contact with the ground surface.3.3.11 IF sampling is not to be completed, THEN CLOSE and LOCK the well.3.3.12 SECURE the area.3.4 Purging the Ground Water to Prepare for Sample Collection 3.4.1 IF directed by Health Physics, SPREAD a clean, unused polyethylene sheet on the around and RETAIN the bailer, nylon string, pump, tubing, battery, electronic water level meter and sample bottles, as appropriate, on the sheet during sampling.3.4.2 MEASURE the depth to ground water surface as described in Section 3.3, and RECORD ori Attachment B.NOTE The well may be purged using a dedicated bailer, bladder, peristaltic, submersible, or Waterra-style pump. The bailer must be wrapped in plastic prior to use and new string attached.3.4.3 RECORD the ground water field parameters on Attachment B.NOTE The purged water and decontamination fluids generated from wells inside the Industrial Area MUST be disposed of under the direction of the Health Physics or Chemistry.

Fluids generated from wells outside the Industrial Area will be either contained for disposal or discharged at the location under the direction of the Health Physics or Chemistry.

SEP 2 9 200?Connecticut Yankee Decommissioning Project 24265-000-GPP-GGGR-R5300-003 Rev. CY-001 Health Physics Procedure Page 6 of 24 3.4.4 LABEL the purge water container(s) with the date, well number and the words "Monitoring Well Purge Water" where required 3.4.5 ARRANGE for transport of purge water container(s) to designated staging area' when sampling is completed.

3.4.6 Equipment* Section 3.1.2 details the equipment needed for low flow purging/sampling, as necessary.

3.4.7 Preliminary Site Activities If the well'casing does not have a reference point (usually a V-cut or mark on'the' well casing), make one. Describe its location and record the date of the mark in the logbook.A water level measurement must be performed before any purging or sampling activities begin as presented in Section 3.3.3.4.8 Procedure'for Low Flow Purging The following procedure will be followed during low flow sampling events: 3.4.8.1 Install Pump or Tubing LOWER purfip, safety' cable, tubing, electrical lines, and air lines SLOWLY (to minimize disturbance) into the well to the midpoint of the zone to be sampled. -NOTE If possible, keep the pump or tubing intake at least two feet above the bottom of the well, to rminimize mobilization of particulates present in the' bottom of the well. Collection of turbidity-free water samples may be especially difficult if there is two feet or less of standing water in the well.

I Connecticut Yankee Decommissioning Project Health Physics Procedure SEP 2 9 2003 24265-000-GPP-GGGR-R5300-003 Rev. CY-001 Page 7 of 24 NOTE When using a peristaltic pump, dedicated tubing shall be lowered to the requisite sample depth and suspended below the well cap at the completion of sampling for future sampling events. Care shall be taken to limit movement of the tubing to minimize mobilization of particulates.

3.4.8.2 Measure Water Level BEFORE starting pump, MEASURE the water level to verify the water displacement has returned to the approximate initial water table level as presented in Section 3.3. Record data on Attachment B.3.4.8.3 Purge Well START the pump at its lowest speed. setting and SLOWLY increase the speed until discharge occurs. Check the water level (Section3.3).

ADJUST the pump speed so that there is little or no water level drawdown (less than 0.3 feet). If the minimal drawdown achieved exceeds 0.3 feet.but remains stable, continue purging until indicator field parameters stabilize.

MONITOR and RECORD the water level and pumping rate every three to five minutes (or as appropriate) during purging and record on Attachment B.NOTE Flow rate ADJUSTMENTS are best made in the first fifteen minutes of pumping to help minimize purging time. During pump start-up, drawdown may exceed the 0.3 feet target and then "recover" as pump flow adjustments are made.NOTE Measure the pumping rate by directing the pump discharge into a graduated beaker and timing the rate at which it fills.

SEP 2 9 2003 Connecticut Yankee Decommissioning Project 24265-000-GPP-GGGR-R5300-003 Rev. CY-001 Health Physics Procedure Page 8 of 24 NOTE Do not allow the water level to fall to the pump intake level (if the static water level is above the well screen, avoid lowering the water level into the screen).3.4.8.4 Low Recharge Wells IF the recharge rate of the well is lower than extraction rate capabilities of currently manufactured pumps, or bailing, and the well is essentially dewatered during purging; THEN the well should be sampled as soon as the water level has recovered sufficiently to collect the appropriate volume needed for all anticipated sampling.

Remove the pump, if used, close and vent the well, periodically monitor the recharge rate of the monitoring well (perhaps several hours, or days) 'and samples may then be collected even though the indicator field parameters have not stabilized pursuant to Section 3.5.3.4.8.5 Monitor Indicator Field Parameters During well purging, MONITOR indicator field parameters (i.e., turbidity, temperature, specific conductance, pH, oxidationireduction potential (Eh), dissolved oxygen (DO), water level) every three to five minutes (or less frequently, if appropriate).

Note: during the early phase of purging, emphasis should be put on minimizing and stabilizing pumping stress, and recording those adjustments.

Purging is considered complete and sampling may begin wvhen all the indicator field parameters have stabilized.

Stabilization is considered to be achieved when three consecutive readings, taken at three (3)'to five (5) minute intervals, are within the following limits: Turbidity (10% for values greater than I NTU);DO (10%);Specific conductance (3%);o'Temperature (3%)_ pH (+ 0.1 standard unit); and Oxidation-Reduction potential/

Eh ( IO 10 mv)

SEP 2 9 2003 Connecticut Yankee Decommissioning Project Health Physics Procedure 24265-OOO-GPP-GGGR-R5300-003 Rev. CY-O0I Page 9 of 24 NOTE If the field parameters are outside of the above limits, CONTACT the ESCS.The ESCS may direct sample collection upon discussion with the field sampling team and/or prior historical knowledge of a specific monitoring well.3.4.8.6 Flow-Through-Cell OBTAIN measurements with a flow-through-cell.

Transparent flow-through cells are preferred, because they allow field personnel to watch for particulate build-up within the cell. If a flow-through-cell cannot be used, partially fill a container with purge water and submerge field parameter measuring devices into the container.

Turbidity measurements may also be measured using a separate meter through a by-pass assembly before the purge water enters the flow-through-cell.

Section 3.5.4 illustrates a typical flow-through-cell.

3.5 Collection of Ground Water Samples NOTE Samples must be obtained using a new polyethylene bailer, dedicated tubing with peristaltic pump, bladder pump, or a submersible pump. With the exception of the dedicated tubing and peristaltic pump, all pumps will be decontaminated using the steps in Section 3.6 of this procedure.

Not all wells may require sample collection.

Sampling needs shall be determined by Final Status Survey supervision at the direction of the client and/or stakeholder(s).

NOTE Personnel performing sampling shall wear new latex or nitrile gloves while collecting samples and not touch the inside surfaces of sample containers or caps. If caps fall on the ground during sampling, a new sample container or cap must be used.

SEP 2 9 2003 Connecticut Yankee Decommissioning Project 24265-000-GPP-GGGR-R5300-003 Rev. CY-00I Health Physics Procedure Page 10 of 24 NOTE Information regarding typical sample containers, volumes and preservatives are discussed in Attachment C of this procedure.

The proper type and amount of sample preservative shall be present in each container prior to filling.NOTE Some environmental samples are required to be stored at 4 to 6 degrees Celsius.A plastic cooler with ice packs shall be used as the sample carrier. Care must be taken to ensure the samples are chilled, but not frozen by maintaining separation between ice packs and environmental samples. Radiological ground water samples are not required to be chilled.NOTE Please review.Attachment D -Low Flow Purging and Sampling Annotations for additional specific information.

3.5.1 SELECT the sample containers to be filled.3.5.2 UNCAP and fill onlv one container at a time.NOTE Treat all samples and equipment as contaminated until analyses prove-- otherwise.

3.5.3 IDENTIFY each samp1l container with the sample idehtificatioh number, date and time of sample collection, analysis requested and preservatives if any. Fill in the information on the label or container with a water-proof indelible pen before sample collection.

Identify the sample as follows: MWXX(*)-YYQQ-XXX

- Where: MWXX indicates monitoring well number where the sample originated.

-* indicates a further optional'alphanumeric descriptor YYQQ indicates sample date (year/quarter)

XXX indicates the number of times the well was sampled during the quarter (e.g.,' each sampling event or group of

-Connecticut Yankee Decommissioning Project Health Physics Procedure SEP 2 9 2003 24265-000-GPP-GGGR-R5300-003 Rev. CY-001 Page 11 of 24 samples collected from a well for a given GWSEP would have the same number.3.5.4 Low Flow Sampling Water samples for laboratory analyses MUST be collected before water has passed through the flow-through-cell (use a by-pass assembly or disconnect cell to obtain sample). A by-pass assembly must be placed upstream of effluent tube and flow-through cell (refer to figure below) to avoid sample off gassing due to pressure changes.Typical Flow-Through Cell Plumbing Sample Bypass (Cjoupling)

From well V_ ,- V7 Flow-through cell Effluent Flow controller (valve)Five gallon bucket VOC sample aliquots should be collected before those for other analytical parameters and put directly into pre-preserved sample containers.

The VOC vial should be tilted on an angle as it is filled. Fill all sample containers by allowing the pump discharge to flow gently down the inside of the container with minimal turbulence.

3.5.5 Bailer Sampling 3.5.5.1 Slowly LOWER the bailer into the well and allow it to fill.3.5.5.2 Slowly WITHDRAW the bailer by the nylon string, coiling the string on the plastic sheet, or drape over hand, so it does not come into contact with the ground.3.5.5.3 WHEN the bailer has been retrieved, EMPTY the bailer such that the contents enter the sample container.

Connecticut Yankee Decommissioning Project Health Physics Procedure SEP 2 9 2003 24265-000-GPP-GGGR-R5300-003 Rev. CY-001 Page 12 of 24 3.5:5.4 REPEAT above steps until desired sample volume is obtained.3.5.6 Add preservative, as required by analytical methods, to samples immediately after they are collected if the sample containers are not pre-preserved.

Check analytical methods (e. g. EPA SW-846, Drinking Water methods, etc.) for additional information on preservation.

3.5.7 Samples of ground water should be collected in the following order, if necessary, after pre-sampling protocols specified in section 3.4.8.5 have been met: 1.2.31.4.5.6.7.8.9.V e o i cd Volatile organic compounds (VOCs);Semivolatile organic compounds (SVOCs);Unfiltered-inorganic compounds; (metals)Filtered inorganic compound, if required PCBs Pesticides Herbicides Cyanide Radiological constituents NOTE If, at any time, a duplicate sample is required, then use one of the extra sets of sample bottles to collect the second sample and label it as a duplicate.

The location and designation of the duplicate shall be noted on Attachment B.3.5.8 Samples collected for'Volatile Organic Compounds (VOC) analyses..NOTE Samples collected for volatile organic co'mpounds must be devoid of air bubbles and the sample must not be aerated during sample collection.

1. ' ENSURE the preservative'is in the VOC container prior to sampling.'. Slowivv FILL the container from a steady flow of water from the bailer or pump.-----__ __

-^ -SEP 2 9 2003 Connecticut Yankee Decommissioning Project 24265-000-GPP-GGGR-R5300-003 Rev. CY-OO1 Health Physics Procedure Page 13 of 24 3. FILL and CAP the container TURN the container upside down and ENSURE that no bubbles are present in the sample container.

4. TAP the container lightly on your hand to dislodge any bubbles.5. IF any bubbles are observed, THEN OPEN the container and slowly add more water.3.5.8.1 Samples collected for other analyses 1. FILL the preserved containers.

leaving a small amount of air space, directly from the bailer or pump tubing.2. ADD preservative, if necessary.

3. CAP the container(s).

3.5.9 INITIATE a Chain-of-Custody form.a. ENSURE the Chain-of-Custody form remains with the sample.3.5.10 When all samples for the well have been collected, REMOVE the bailer and/or pump and tubing from the well.a. PLACE the cap back onto the well and CLOSE the lock and road box, if applicable.

b. Dispose of, or STORE, sampling materials in a separate place.3.5.11 IF rinsate samples are required to be collected pursuant to the sampling plan, OBTAIN rinsate samples from the pump to demonstrate the efficiency of the decontamination method.a. PERFORM decontamination of pump as presented in Section 3.6.b. PUMP de-ionized water through the tubing into appropriate container(s) for analyses using the pump that has been decontaminated.
c. LABEL and MANAGE the rinsate samples per Sections 3.5.1 -3.5.8, with the exception that they are not processed through the flow-through-cell and arc labclcd as "rinsate" samples in place of"Well Number".3.5.12 At the end of the sampling period, BRING the samples to the designated storage location.

SEP 2 9 403 Connecticut Yankee Decommissioning Project 24265-000-GPP-GGGR-R5300-003 Rev. CY-I Health Physics Procedure Page 14 of 24 a. RELINQUISH samples via the Chain-of-Custody form.-3.5.13 START a new Attachrment B for each monitoring well sampled and COMPLETE the sections for the well sampled.a. FORWARD Attachmept B pages to the Environmental Site Closure Supervisor,.

b. INCLUDE a copy of the Chain-of-Custody form, blanks and other samples in the shipment of samples to the analytical laboratory.
c. PLACE sample containers into a shipping container, cool to 4 0 C with ice packs, if necessary.

Pad the samples with bubble wrap, styrofoam and/or vermiculite packing as necessary.

3.6 Decontamination

--3.6.1 DISPOSE of single-use bailers, tubing and rope/string used for ground water sampling after each use in radwaste trash receptacle, as appropriate.

3.6.2 DECONTAMINATE the field meter and field parameter probes, and measuring beaker before sampling each well.a. FILL a spray bottle with de-ionized water and alconox soap, or equivalent.

b. SPRAY the probes and measuring container(s) with the soap solution.c. RINSE the probes and measuring container(s) with de-ionized water from a second spray bottle.d. COLLECT the rinse water if required e. STAGE the probes in the equipment storage container.

3.6.3 DECONTAMINATE sampling pump in the field prior to sampling each well following one of these procedures:

Method 1 a. FILL one PVC tube with a mixture of alconox soap, or equivalent, and de-ionized water.b. FILL a second PVC tube with distilled water.c. PLACE pump in first tube and set discharge tubing so it flows back into the tube.d. RUN pump so the solution goes through the pump and back into the PVC tube for several minutes.

SEP 2 9 2003 Connecticut Yankee Decommissioning Project 24265-000-GPP-GGGR-R5300-003 Rev. CY-001 Health Physics Procedure Page 15 of 24 e. REMOVE pump from first tube and wipe with clean cloth or paper towel(s).f. PLACE pump into second tube and repeat steps c and d above.g. REMOVE pump from second tube and wipe down with clean cloth or paper towel(s).h. COLLECT the rinse water into container(s), if required i. PLACE pump in pump stand holder.Method 2 (For use with bladder pumps)a. WASH external components of the pump (also wash tubing and air line if not dedicating these to individual wells) with alconox soap solution afid rinse with de-ionized water as pump is withdrawn from the well.b. WIPE external components down with clean cloth or paper towel(s).c. PUMP a dilute mixture of alconox soap, or equivalent, and de-ionized water through the bladder pump using a peristaltic pump.d. RUN pump so the solution goes through the pump for several minutes and discharge into waste container.

e. RINSE by pumping a volume of de-ionized water through the pump using the persistaltic pump and discharge into waste container.
f. COLLECT the rinse waters into waste container(s), if required.g. PLACE pump in pump stand holder.

Connecticut Yankee Decommissioning Project Health Physics Procedure 24265-000-GPP-GGGR-R5300-003 Rev. CO-2001.v -.. Page 16 of24-3.7 Sample Collection and Handling Controls NOTE Care must be taken to avoid potential cross contamination of environmental samples and sample containers.

Sample containers, coolers, and sampling equipment must never be stored near gasoline, solvents, or other equipment and /or fluids that may present a source of contamination.

.3.7.1 ; Trip Blanks ' i rI NOTE Trip blanks are required for aqueous sampling events for which VOC analyses will be performed.

Trip blank samples are used to document'potential cross contamination of samples due to container contamination, and/or induction of c6ntamination'during sampling and transport of containers from the laboratory into the field and then shipment back to the' analytical laboratory.

NOTE Trip blanks consist of a set of sample bottles filled at the laboratory with laboratory-grade water. These sample bottles accompany the empty sampling containers, supplied by the laboratory, to the site, into the field during the sampling sent, and then back to the laboratory.

Trip blanks will be analyzed for volatile organic compounds (VOCs).a. The specific GWSEP will DETERMINE the number of trip blank samples required for the monitoring event.' One trip blank is required for each day VOC sample containers are transported from the site to the analytical laboratorv.

If no VOC samples are collected on a given day, then a trip blank is not required to be included in the shipping container.

Likewise, if multiple samples are collected in a given day and several shipping containers are used, place all VOC samples into one shipping container and then only one trip blank is required.

-a J Connecticut Yankee Decommissioning Project Health Physics Procedure SEP 2 9 2003 24265-000-GPP-GGGR-R5300-003 Rev. CY-00I Page 17 of 24 I NOTE Trip Blank bottles are never to be opened in the field. Trip blank samples should be chilled (e.g. maintained in a cool to 4 0 C condition) only after the accompanying sample containers have been filled and are prepared for off-site shipment.3.7.2 Duplicate Samples Field duplicate samples, if required by the GWSEP, are two separate samples taken from the same source and are used to determine data repeatability based on field conditions.

Duplicate samples are collected by alternately filling the environmental sample container and the duplicate sample container.

Duplicate samples should be preserved and handled in the same manner as environmental samples. Duplicate samples shall be analyzed for the same parameters as the associated environmental samples.NOTE Selection of duplicate samples shall be biased toward locations that have indicated, or are suspected, of being the most heavily impacted with the analyte(s) of interest and will be detailed within the specific ground water sampling plan for a particular sampling event.4.0 ATTACHMENTS 4.1 Attachment A -Synoptic Water Level Measurement Data Sheet 4.2 Attachment B -Ground Water Monitoring Well Data Logs 4.3 Attachlment C -Typical Sample Containers, Volumes, Preservatives and Holding Times for Various Analyses 4.4 Attachment D -Low Flow Purging and Sampling Annotations Connecticut Yankee Decommissioning Project Health Physics Procedure SEP 2 9 2003 24265-000-GPP-GGGR-R5300-003 Rev. CY-00I Page 18 of 24 5.0

SUMMARY

OF CHANGES Section/Paralraph Change Reason 3.1 Added various pump types More flexibility 3.4 Added ability to pour sample, If allowed by Chem Waste Permit.decon fluid to ground.Added alternate turbidity More flexibility measurement method.ALL Revised minor typos, title, name changes SEP 2 9 2003 Connecticut Yankee Decommissioning Project Health Physics Procedure 24265-000-GPP-GGGR-R5300-003 Rev. CY-001 Page 19 of 24 ATTACHMENT A -Synoptic WVater Level Measurement Data Sheet Summary of Denth-to-Water Measurements Depth to Monitoring Well Location and Water in Feet Identification From TIC MW- 0OD MW-100S MW-101D MW-101S _MW-102D MW-102S ___ _MW-103D MW-103S MW-104S MW-105D MW-105S MW-106D MW-106S MW-107D MW-107S MW-108S MW- 09D MW-109S MW-11OD MW-i10S MW- 14S MW-115S AST-1 MW-111S MW- 12S MW- 13S MW-1 17S MW-13 TW-1 EOF-2 MW-200 MW-201 MW-202 MW-203 MW-204 MW-205 MW-206 MW-207 Boat Dock TIC: Top of Inner Casino Date:_Time Started: Time Finished:_

Prepared By:_Field Observations/Coniinent Section:

Co( -cut Yankee Decommi ission ing Project Healtn Physics Procedure 2 -G bLP 2 9 2003 24f AJO-Gr(P-UGGR-R5300-003 Page 20 of 24 (ATTACHMENT B -Ground Water Monitoring WVell Data Log Date:__ _Monitoring Well ID: -Pump Set Depth: Static Water Level: Name: All Depths Are-Feet Below Top Of Inner Casing (TIC)TIME Frequeency Discharge CIII11. .Field Parameters

.(military)

Rate Purge DTW Turbidity DO Eli pl1 Specific Temperature Volume Conduictance

.(cycles/sec) (iL/mmi) (gallons) (reet) (NTU) (mg/L) (mv) (S.U.) (us/cm) (degree C)lnstruiment Modlel/Serial Number(s):

Calibration Date(s):

SEP 2 9 2003 Connecticut Yankee Decommissioning Project Health Physics Procedure 24265-000-GPP-GGGR-R5300-003 Page N-of 24 u!5 4/'-/J ATTACHMENT C Typical Sample Containers, Volumes, Preservatives and Holding Times for Various Analyses Analytical Suite Volume/Sample Preservative Holding Time Container Volatile Organic (2) 40 ml. glass vial Acidified to pH <2 14 days Compounds with VOC grade Hydrochloric acid (HCL) Keep at 4 'C Metals 500 ml polyethylene Acidified with reagent 6 months (except Hg grade nitric acid which is 28 days)(HNO 3)to pH <2 Cyanide I liter, polyethylene NaOH added to p'.1 >12 14 days Herbicides 1 liter, amber glass Keep at 4 0 C 7 day pre-extraction 40 day post-extraction Pesticides I liter, amber glass 40 C 7 day pre-extraction 40 day post-extraction PCBs I liter, amber glass 40 C 7 day pre-extraction 40 day post-extraction SVOCs I liter, amber glass 40 C 7 day pre-extraction 40 day post-extraction Connecticut Yankee Decommissioning Project Health Physics Procedure SEP 2 9 2003 24265-000-GPP-GGGR-R5390-003 Pagefi of 24 ATTACHMENT C Typical Sample Containers, Volumes, and Preservatives for Various Analyses Radionuclide Ground WaterEPDrnkg Concentration Equivalent WaePA Drinking to 1 mrem/yr(')

Water MCL (pCi/)Required MDCC 2)(pCi/1)Analysis Category H-3 C-14 Mn-54 Fe-55 Co-60 Ni-63 Nb-94 Ag-108m Eu-152 Eu-154 Eu-155 Sr-90 Tc-99 Cs-134 Cs-1 37 Pu-238 Pu-239 Pu-241 Am-241 .Cm-243 26080 360 968 2616 46 1260 270 170 293 202 1300 10 1056 14 17 0.60 0.54 28.40 0.53 0.78 20000 2000 300.2000 100 50 60 200 600 400 200.. 50.25 25 15 50 50 50 50 50 LSC LSC Gamma LSC Gamma LSC Gamma'Gamma Gamma Gamma, Gamma LSC LSC Gamma Gamma Alpha Alpha LSC Alpha Alpha I .,. Ie.8., #900 20000---20-15 15 15 -15 2 15 14 15 0.50 0.50 15 0.50 0.50 Summary Gross Alpha/Beta Preservative Nitric acid pH<2 (5 ml)Container 1 liter HDPE Gamma Isotopic Nitric acid pH<2 (20 ml) 4 liter HDPE Hard to Detects -Alpha Isotopic Nitric acid pHc2 (20 ml) 4 liter HDPE H-3 None 250 ml glass C-14 None (no headspace air) 250 ml glass Fe-55 Nitric acid pH<2 (20 ml) 4 liter HDPE Ni-63 Nitric acid pH-<2 (20 ml) 4 liter HDPE Sr-90 Nitric acid pH<2 (20 ml) 4 liter HDPE Tc-99 Nitric acid pH<2 (20 ml) 4 liter HDPE Pu-241 Nitric acid pH<2 (20 ml) 4 liter HDPE (1) These values are derived from the LTP Ground Water DCGLs (2) MDC = Minimum Detectable Concentration to meet the DQO* For the purpose of attaining analyte sensitivities required to demonstrate compliance with the License Termination Plan (LTP) DCGLs or Water Quality Standards (WQS), a generic DQO is an acceptable approach to Qi ensure quality data since numerous levels of quality assurance are built into analytical laboratory performance and chain of custody requirements.

SEP 2 9 2003 Connecticut Yankee Decommissioning Project 24265-000-GPP-GGGR-R54Q0-003 Health Phvsics Procedure Pane.> of 24 Attachment D Low Flow Purging and Sampling Annotations Purpose of Low Flow Ground Water Sampling The purpose of low flow (low stress) purging and sampling is to collect ground water samples that are representative of ground water quality under approximate natural flow conditions.

The presence and concentration of dissolved organic and inorganic pollutants as well as the pollutants associated with mobile particulates are most accurately revealed through low flow sampling.Low flow sampling techniques minimize stress on the aquifer by utilizing low pumping rates that result in minimal water level drawdowns.

Presence of NAPLs Check newly constructed wells for the presence of light non-aqueous phase liquids (LNAPLs) or dense non-aqueous phase liquids (DNAPLs) with a product level interface probe before the initial sampling round. Low flow sampling may be an inappropriate method for sampling ground water with non-aqueous phase liquids (NAPLs). Procedures for the collection of LNAPL and DNAPL samples are not addressed in this Procedure.

Measurement and Cleaning of the Flow-Throuah-Cell Transparent flow-through cells are preferred, because they allow field personnel to watch for particulate build-up within the cell. This build-up may affect indicator field parameter values measured within the cell and may also cause an under-estimation of turbidity values measured after the cell. If the cell needs to be cleaned during purging operations, continue pumping and disconnect cell for cleaning, then reconnect after cleaning, and continue monitoring activities.

Additional Control of Discharee Flow During purging and sampling, the tubing should remain filled with water to minimize possible changes in water chemistry upon contact with the atmosphere.

It is recommended that 1/4 -inch or 3/8-inch (inside diameter) tubing be used to help insure that the sample tubing remains water filled. If the pump tubing is not completely filled to the sampling point. use one of the following procedures to collect samples: (1) add clamp, connector or valve to constrict sampling end of tubing; (2) insert small diameter tubing into water filled portion of pump tubing allowing the end to protrude beyond the end of the pump tubing, collect sample from small diameter tubing: (3)collect non-VOC samples first, then increase flow rate slightly until the water completely fills the tubing. collect VOC sample and record new drawdown, flow rate and new indicator field parameter values on Attachment B.

Connecticut Yankee Decommissioning Project Health Physics Procedure SEP 2 9 20D3 24265-000-GPP-GGGR-R5300-003 Page 24 of 24 6.0 BASIS 6.1 "Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM)" (NUREG-1575) recommends that as part of the decommissioning process, a suitable monitoring well network be set up to sample ground water for possible contamination.

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