ML14071A159

5: Fact Sheet for NPDES Permit WA002515-1, Columbia Generating Station

ML14071A159
Person / Time
Site:	Columbia
Issue date:	01/15/2014
From:	State of WA, Energy Facility Site Evaluation Council
To:	Office of Nuclear Reactor Regulation
Lyon C
References
TAC MF3501
Download: ML14071A159 (70)

Text

Fact Sheet for NPDES Permit WA002515-1 Columbia Generating Station January 15, 2014 Purpose of this fact sheet This fact sheet explains and documents the decisions the Energy Facility Site Evaluation Council (EFSEC) made in drafting the proposed National Pollutant Discharge Elimination System (NPDES) permit for Columbia Generating Station.

This fact sheet complies with Section 463-76-034 of the Washington Administrative Code (WAC), which requires EFSEC to prepare a draft permit and accompanying fact sheet for public evaluation before issuing an NPDES permit.

EFSEC makes the draft permit and fact sheet available for public review and comment at least thirty (30) days before issuing the final permit. Copies of the fact sheet and draft permit for Columbia Generating Station, NPDES permit WA002515-1, are available for public review and comment from February 3, 2014 until March 14, 2014. For more details on preparing and filing comments about these documents, please see Appendix A - Public Involvement Information.

Energy Northwest reviewed the draft permit and fact sheet for factual accuracy. EFSEC corrected any errors or omissions regarding the facilitys location, history, discharges, or receiving water prior to publishing this draft fact sheet for public notice.

After the public comment period closes, EFSEC will summarize substantive comments and provide responses to them. EFSEC will include the summary and responses to comments in this fact sheet as Appendix E - Response to Comments, and publish it when issuing the final NPDES permit. EFSEC will not revise the rest of the fact sheet, but the full document will become part of the legal history contained in the facilitys permit file.

Summary Energy Northwest operates a nuclear-fueled steam electric power generation plant that discharges to the Columbia River and to ground water. EFSEC issued the current permit for this facility on May 25, 2006. The current permit contains a compliance schedule requiring a number of activities that informed permit reissuance including; a ground water study, an effluent mixing study, and visual inspection of Outfall 001. Energy Northwest also replaced the main steam condenser in 2011, removing a source of copper from discharges to Outfall 001.

Effluent limits for pH, flow, total residual halogen, polychlorinated biphenyl compounds (PCBs),

and priority pollutants contained in chemicals added for cooling system maintenance are unchanged from the permit issued in 2006. EFSEC updated effluent limits for temperature and copper based on the effluent mixing study. Technology-based limits were added for chromium and zinc. The proposed permit includes a schedule of activities to address temperature monitoring and compliance with ground water quality standards.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 2 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Table of Contents I.

Introduction............................................................................................................ 5 II.

Background Information....................................................................................... 6 A.

Facility description................................................................................................ 7 History................................................................................................................................ 7 Industrial Processes............................................................................................................. 8 Wastewater Treatment processes........................................................................................ 8 Solid wastes...................................................................................................................... 12 Sanitary wastes................................................................................................................. 12 Discharge outfalls............................................................................................................. 13 B.

Description of the receiving water..................................................................... 15 C.

Wastewater characterization............................................................................. 16 D.

Summary of compliance with previous permit issued May 25, 2006............. 18 E.

State environmental policy act (SEPA) compliance........................................ 19 III.

Proposed Permit Limits........................................................................................ 19 A.

Technology-based effluent limits....................................................................... 20 Total Residual Halogen.................................................................................................... 20 Cooling Water Intake Structures....................................................................................... 21 B.

Surface water quality-based effluent limits...................................................... 25 Numerical criteria for the protection of aquatic life and recreation.................................. 25 Numerical criteria for the protection of human health...................................................... 25 Narrative criteria............................................................................................................... 25 Antidegradation................................................................................................................ 26 Mixing zones..................................................................................................................... 26 C.

Designated uses and surface water quality criteria......................................... 31 D.

Water quality impairments................................................................................ 32 E.

Evaluation of surface water quality-based effluent limits for numeric criteria

............................................................................................................................... 32 Reasonable Potential Analysis.......................................................................................... 36 F.

Human health...................................................................................................... 37 G.

Sediment quality.................................................................................................. 38 H.

Groundwater quality limits................................................................................ 38 I.

Whole effluent toxicity........................................................................................ 39 J.

Comparison of effluent limits with previous permit issued May 25, 2006.... 40 Temperature...................................................................................................................... 40 Copper............................................................................................................................... 41 Chromium and Zinc.......................................................................................................... 41 IV.

Monitoring Requirements.................................................................................... 42

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 3 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 A.

Lab accreditation................................................................................................ 43 B.

Effluent limits which are near detection or quantitation levels...................... 46 V.

Other Permit Conditions...................................................................................... 46 A.

Reporting and record keeping........................................................................... 46 B.

Non routine and unanticipated discharges....................................................... 46 C.

Spill plan.............................................................................................................. 46 D.

Solid waste control plan..................................................................................... 47 E.

Outfall evaluation................................................................................................ 47 F.

Operation and maintenance manual................................................................. 47 G.

Stormwater pollution prevention plan.............................................................. 47 Best Management Practices (BMPs)................................................................................ 47 Ecology-Approved Stormwater Management Manuals.................................................... 48 Operational Source Control BMPs................................................................................... 48 Structural Source Control BMPs...................................................................................... 48 Treatment BMPs............................................................................................................... 49 Volume/Flow Control BMPs............................................................................................ 49 H.

Compliance schedule.......................................................................................... 49 I.

General conditions.............................................................................................. 50 VI.

Permit Issuance Procedures................................................................................ 50 A.

Permit modifications........................................................................................... 50 B.

Proposed permit Issuance.................................................................................. 50 VII.

REFERENCES FOR TEXT AND APPENDICES............................................ 51 Appendix A--Public Involvement Information........................................................................... 53 Appendix B--Appeals of the NPDES Permit............................................................................... 57 Appendix C--Glossary.................................................................................................................. 58 Appendix D--Technical Calculations.......................................................................................... 66 Appendix E--Response to Comments.......................................................................................... 70 Table 1 General Facility Information............................................................................................ 6 Table 3 Wastewater Characterization - Outfall 001.................................................................... 16 Table 4 Wastewater Characterization - Outfall 002.................................................................... 17 Table 5 Technology-based Limits............................................................................................... 20 Table 6 Critical Conditions Used to Model the Discharge.......................................................... 28 Table 7 Freshwater Aquatic Life Uses and Associated Criteria.................................................. 31

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 4 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Table 9 Dilution Factors (DF)...................................................................................................... 34 Table 10 Comparison of Previous and Proposed Effluent Limits............................................... 40 Table 11 Accredited Parameters.................................................................................................. 43 Figure 1 Facility Location Map...................................................................................................... 7 Figure 2 Columbia Generating Station Flow Diagram................................................................... 9 Figure 3 Columbia Generating Station Regulatory Mixing Zone................................................ 33 Figure 4 Dilution Necessary to Meet Criteria at Edge of Mixing Zone....................................... 37

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 5 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 I.

Introduction The Federal Clean Water Act (FCWA, 1972, and later amendments in 1977, 1981, and 1987) established water quality goals for the navigable (surface) waters of the United States. One mechanism for achieving the goals of the Clean Water Act is the National Pollutant Discharge Elimination System (NPDES), administered by the federal Environmental Protection Agency (EPA). The EPA authorized the state of Washington to manage the NPDES permit program in our state. Our state legislature accepted the delegation and assigned the power and duty for conducting NPDES permitting and enforcement to the Department of Ecology (Ecology) and the Energy Facility Site Evaluation Council (EFSEC). The Legislature defined EFSEC's authority and obligations for the wastewater discharge permit program in 90.48 RCW (Revised Code of Washington).

The following regulations apply to industrial NPDES permits:

Procedures EFSEC follows for issuing NPDES permits (chapter 463-76 WAC)

Water quality criteria for surface waters (chapter 173-201A WAC)

Water quality criteria for ground waters (chapter 173-200 WAC)

Whole effluent toxicity testing and limits (chapter 173-205 WAC)

Sediment management standards (chapter 173-204 WAC)

Submission of plans and reports for construction of wastewater facilities (chapter 173-240 WAC)

These rules require any industrial facility owner/operator to obtain an NPDES permit before discharging wastewater to state waters. They also help define the basis for limits on each discharge and for performance requirements imposed by the permit.

Under the NPDES permit program and in response to a complete and accepted permit application, EFSEC must prepare a draft permit and accompanying fact sheet, and make them available for public review before final issuance. EFSEC must also publish an announcement (public notice) telling people where they can read the draft permit, and where to send their comments, during a period of thirty days (WAC 463-76-041). (See Appendix A-Public Involvement Information for more detail about the public notice and comment procedures).

After the public comment period ends, EFSEC may make changes to the draft NPDES permit in response to comment(s). EFSEC will summarize the responses to comments and any changes to the permit in Appendix E.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 6 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 II.

Background Information Table 1 General Facility Information Facility Information Applicant:

Energy Northwest Facility Name and Address Columbia Generating Station P.O. Box 968 (Mail Drop PE20)

Richland, WA 99352 Contact at Facility Name: Brad C. Barfuss Telephone #: 509-377-4541 Responsible Official Name: Dale K. Atkinson

Title:

Vice President, Employee Development/Corporate Services Address: P.O. Box 968 (Mail Drop PE03), Richland, WA 99352-0968 Telephone #: 509-377-4302 Industry Type Electric Services Categorical Industry 40 CFR Part 423 Steam Electric Power Generating Point Source Category Type of Treatment Cooling, disinfection, neutralization (blowdown)

Filtration, ion exchange (processed radwaste water)

SIC Codes 4911 NAIC Codes 221113 Facility Location (NAD83/WGS84 reference datum)

Latitude: 46.47170 Longitude: 119.33280 Discharge Waterbody Names and Locations (NAD83/WGS84 reference datum)

Outfall 001 - Columbia River (river mile 351.75)

Latitude: 46.47139 Longitude: 119.26250 Outfall 002 - Ground Water Latitude: 46.47389 Longitude: 119.32861 Permit Status Renewal Date of Previous Permit May 25, 2006

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 7 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Permit Status Application for Permit Renewal Submittal Date November 24, 2010 Date of Council Acceptance of Application December 29, 2010 Inspection Status Date of Last Non-sampling Inspection Date November 8, 2012 Figure 1 Facility Location Map This image is from the Ecologys Facility/Site Database (http://www.ecy.wa.gov/fs/). The Columbia Generating Station is on the left side of the image with the Columbia River approximately three miles east and shown at the right border.

A. Facility description History The Columbia Generating Station (CGS) is a 1,170-megawatt boiling water reactor that uses nuclear fission to produce heat. It is owned and operated by Energy Northwest and located on the U.S. Department of Energy (USDOE) Hanford Site in Benton County about 12 miles north of Richland, Washington. CGS employs about 1,100 people and produces electricity 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> a day, 7 days a week when in operation. The reactor is shut down approximately every Columbia Generating Station Outfall 001 Outfall 002 River Pumphouse

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 8 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 two years for maintenance. It produces eight to nine billion kilowatt-hours of electricity annually, representing four percent of the power consumed in the northwest.

The 1,089 acre site includes several buildings and structures located three miles west of the Columbia River. Construction of the plant began in 1973. The Nuclear Regulatory Commission (NRC) issued an operating license in 1983 and the first electricity was produced in May of 1984. In May 2012, NRC issued a renewed operating license to Energy Northwest which expires 12/20/2043.

Energy Northwest replaced the main steam condenser during a 2011 refueling outage. The admiralty brass condenser tubes were replaced with titanium to reduce copper content in reactor feed water and blowdown, reduce radiation exposure, and improve operational efficiencies.

The Columbia Generating Station permit qualifies as a U.S. Environmental Protection Agency (EPA) major permit.

Industrial Processes The Columbia Generating Stations (CGS) Standard Industrial Classification (SIC) Code is 4911, Electric Services. The North American Industry Classification System (NAICS) Code is 221113, Nuclear Electric Power Generation. The facility is subject to EPA Categorical Pretreatment Standards 40 Code of Federal Regulations (CFR) Part 423 Steam Electric Power Generating Point Source Category.

The main activity at the site is production of commercial electric power from nuclear energy.

The boiling water type nuclear reactor uses light water as the moderator and enriched uranium in pellet form as the nuclear fuel. Demineralized water passes around zirconium tubes containing the reactor fuel in the core and is converted to steam at about 70 atmospheres (1000 psi). The electrical generator is turned by a steam powered turbine converting thermal energy to mechanical energy and ultimately to electrical energy.

The primary use for the process water is non-contact cooling water. Flow is recirculated through six mechanical draft cooling towers where heat is rejected to the atmosphere.

Evaporation, drift, and blowdown losses are replenished from the Columbia River. Energy Northwest also produces potable water and water for use in the reactor on-site.

This NPDES permit covers discharges of pollutants not otherwise covered by Council Resolution or other authority, such as the NRC, in any wastewater discharges to waters of the state.

Wastewater Treatment processes Several separate internal waste streams and their respective treatment systems discharge to two outfalls. The fact sheet describes each process below, organized by outfall. Energy Northwest submitted a flow diagram with the permit application that illustrates wastewater flows at the Columbia Generating Station. Shown here as Figure 2.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 9 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Figure 2 Columbia Generating Station Flow Diagram Discharges to Outfall 001 (Columbia River at river mile 351.75) include:

Circulating cooling water blowdown - The major waste stream, in terms of volume, is the blowdown from the non-contact circulating cooling water system which cools the steam condenser and associated machinery. This water is circulated at approximately 600,000 gallons per minute (gpm), cooled by the evaporative process in six mechanical draft cooling towers, and recycled.

The cooling tower evaporation and drift losses average 13,500 gpm. Even with replenishment of these losses with new water, the evaporation concentrates the dissolved solids in the circulation water to the point that salts would cause excessive deposition in the system, impeding efficiency. To limit the build-up of mineral salts to tolerable levels, a small portion (typically <5%) of the water is released to Outfall 001 as blowdown. The blowdown discharge is nearly continuous with a maximum flow rate of 6,500 gpm and an average between 2,850 gpm at five cycles of recirculation and 850 gpm at 12 cycles. The permit application reports an average flow of 1,695 gpm.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 10 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Energy Northwest adds chemicals to inhibit deposition of solids and to limit corrosion and biological growth in the system. Sulfuric acid is added to maintain pH. A polyphosphate blend is used for corrosion inhibition in mild steel and a phosphonate copolymer to minimize scale formation. Sodium tolytriazole is added separately for copper alloy corrosion control. Microbiocidal treatment is provided with sodium hypochlorite and sodium bromide two to three times per week. Blowdown is terminated during biocide treatment to allow halogen residual to decay. The discharge contains heat, residuals from treatment additives, constituents from the intake Columbia River water (concentrated by evaporation), and system corrosion products.

Periodically the main condenser becomes scaled. This reduces plant efficiency to the point that chemical cleaning of the main condenser is necessary. During cleaning, blowdown is stopped and a cleaning agent is added to the circulating water system.

At the completion of the cleaning process, if any permit condition is not met, circulating water is pumped to a storage location using temporary pumps and piping.

During this pumping process, the concentration of constituents in the circulating water is reduced by the addition of makeup water from the river. When the circulating water meets all conditions for the discharge, blowdown to the river is initiated. After the condenser cleaning process is completed, the stored water will be treated (if necessary) to meet discharge requirements, then discharged. Any sediment from the cleaning process is analyzed and disposed of in accordance with the facilitys solid waste control plan.

Energy Northwest replaced the main condenser in September 2011. The admiralty brass condenser tubes were replaced with titanium, removing a significant source of copper from this discharge.

Service water system blowdown - The service water system is a separate non-contact cooling water supply and distribution system that serves two purposes: cooling the reactor in the event of malfunction of the regular cooling system, and removing residual heat from the reactor during reactor shutdown periods. The closed-loop system contains approximately twelve million gallons of water in two interconnected basins with an evaporative spray cooling system.

Microbial growth is controlled with periodic batch additions of 50% hydrogen peroxide and Busan 77. The service water is also treated with sodium silicate for corrosion inhibition. Blowdown of this system is conducted infrequently to reduce concentrations of sulfur, chloride, suspended solids or to drain a basin for maintenance. Discharge may reach 4,000 gpm when it occurs and was last reported in April 2013. The discharge contains concentrated minerals, other constituents of the makeup water, and some material corrosion and wear products. Refer to Section II.A.

Discharge Outfalls below for further detail on this discharge.

Radioactive wastewater treatment system effluent - This is treated wastewater from the primary water system (reactor water for steam production) that Energy Northwest must occasionally discharge when the inventory becomes excessive or when the quality in terms of organic content does not meet specifications. The primary water (produced on site), is very pure (conductivity generally less than 0.2

µmho/cm) but still has the potential for some radioactive contamination. For this

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 11 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 reason, it is filtered and treated through an ion exchange process to reduce radioactive impurities prior to discharge.

The facility discharges this wastewater in batches (15,000 gallons at up to 190 gpm),

only after assurance that NRC-dictated radioactivity discharge limits are met. The facilitys water management practices make this an infrequent discharge, last occurring September 19, 1998.

Discharges to Outfall 002 (evaporation/leach pond) include:

Wastewater from potable water production system - This system processes either river or well water through multimedia filtration with flocculent assistance. The wastewater is filter backwash and amounts to 15,000-25,000 gallons in volume two or three times per week. It contains the removed impurities and the flocculent.

Wastewater from demineralized water treatment system - This system produces water for the reactor steam cycle from the potable water supply. The wastewater is composed of instrument flush water and reverse osmosis reject water. The estimated average discharge is 17,000 gallons per day. It contains natural impurities removed in the treatment process.

Stormwater from plant building roof drains - The estimated annual average of this discharge is 1,800 gallons per day. Stormwater runoff from other parts of the site, including building roofs and paved areas, is routed to dry wells or enters the soil directly. The facility does not generate runoff that EFSEC would consider as associated with industrial activity and it does not discharge stormwater to surface waters.

Wastewater from drains in General Services and Diesel-Generator Buildings - The General Services Building sump drain collects water from equipment drains and area floor drains. Water sources directed to the sump include HVAC units, intake air washers, pump and valve leakage, demineralized water storage tank overflows, and floor washings. A level switch activates the sump pump and causes the collected water to discharge through Outfall 002. A discharge of 3,000 gallons occurs infrequently, two to three times per year.

The Diesel-Generator Building floor drains are connected directly to the discharge pipe to Outfall 002. Among the few sources of discharge to these floor drains are the diesel engine cooling jackets from which approximately 3,800 gallons of water treated with a nitrite-based corrosion inhibitor are drained about once a year.

Wastewater from Turbine Generator Building sumps - Three non-radioactive sumps in the Turbine Generator Building collect wastewater from equipment leakage, washing, and maintenance activities (such as condenser drainage). These sumps could previously be routed to Outfall 002 via the storm drainage system after sampling verified it contained no detectable radioactivity. The normal alignment of these sumps is to the radioactive wastewater treatment system that discharges to Outfall 001 as necessary. They are no longer physically connected to the storm drainage system discharging to Outfall 002.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 12 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Stormwater and/or deluge testing water from the transformer yard -Stormwater and deluge testing water currently discharge to ground. A proposed transformer yard oil collection system would collect stormwater and deluge testing water immediately around each transformer and discharge directly to the evaporative ponds once constructed..

Stormwater discharges:

Underground injection control (UIC) wells - Stormwater runoff from parking lots, support building, and other impervious surfaces are discharged to multiple UIC wells at the facility. The UIC wells are registered with the Department of Ecology (Ecology). The proposed permit requires development and implementation of a stormwater pollution prevention plan (SWPPP) to address these discharges.

Specifically, the SWPPP will be used to address the facilities requirement to meet the nonendangerment standard under Chapter 173-218-090. The SWPPP will also address other miscellaneous discharges to ground that may or may not discharge directly to a UIC well including: fire protection system flushing and flow-rate tests, maintenance, and minor construction discharges. Discharges to ground not addressed in the SWPPP may be addressed through S8. Non-routine and unanticipated discharges of the proposed permit.

Solid wastes Several waste streams from the facility are addressed in the Solid Waste Control Plan.

General refuse, scrap metal, metal and polyurethane drums, and worn vehicle and equipment tires are recycled or disposed of off-site. Demolition and construction debris are primarily disposed of at the City of Richland Municipal Landfill. Energy Northwest can also dispose of some waste in the onsite inert waste landfill. Used oil and hydraulic fluid is collected in drums until recyclable quantities are accumulated and transported off-site for recycling.

Petroleum contaminated soils are land-farmed at the City of Richland Municipal Landfill or transported to a hazardous waste landfill off-site.

Cooling system sediments from the cooling tower decks and basins are collected approximately annually and placed in a disposal cell south of the towers. Sediments are periodically removed from the service water spray ponds and disposed of in the cooling tower sediment disposal cells.

Council Resolution or other authority such as the Nuclear Regulatory Commission regulates the handling, treatment, storage, disposal and release of dangerous and radioactive wastes.

The scope of the proposed permit does not include these activities beyond the requirement in S5.A to follow the procedures in the most current resolution pertaining to the disposal of sediments from the cooling water system and double-lined impoundment.

Sanitary wastes Sanitary waste from the facility is piped to a treatment system located approximately 1/2 mile to the southeast. The facility uses aeration lagoons and facultative stabilization ponds to treat sanitary waste. Discharge of treated wastewater to ground is covered by Council Resolution No. 300, available here: http://www.efsec.wa.gov/FILES/resolutions/300.pdf. It is not covered by this permit, and will not be addressed further in this fact sheet.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 13 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Discharge outfalls The treated and disinfected effluent flows into either the Columbia River or ground water through two outfalls:

Outfall 001 discharges to the Columbia River at river mile 351.75. At minimum regulated flow (36,000 cfs), a buried 18 inch pipe emerges at the outfall approximately 175 feet from the west shoreline and at a depth of seven feet. The slot-nozzle outfall is aligned perpendicular to the river flow, is 8 inches high, 32 inches wide, and extends upward from the river bed at a 15º angle. Energy Northwest evaluated the discharge structure in October 2006 and determined that it was in its original configuration and functioning as designed.

Outfall 002 discharges through a concrete weir to an unlined channel that empties into a small infiltrating pond located approximately 1500 feet northeast of the plant. The proposed permit requires installation of a double-lined evaporation pond in place of the infiltrating pond.

Previous permits and the 2006 permit authorized discharge of filter backwash associated with cleaning of the standby service water ponds to Outfall 003, a surface depression about 500 feet south of the service water ponds. The proposed permit does not authorize discharges to Outfall 003.

Energy Northwest removed sediment from the service water ponds in March 2013. Divers removed sediment by vacuuming the bottom of the ponds using a closed-loop system that filtered and returned excess water to the ponds. Sediment was disposed of in designated disposal cells per EFSEC Resolution 299, which authorizes the disposal of sediment removed from the ponds and the cooling towers. The sediments may contain very low levels of radionuclides from the Columbia River, from the surrounding soil, and from the plant. For this reason, EFSEC works closely with the Washington State Department of Health (WDOH) in addressing these sediments.

The following April 2013 communication from WDOH staff summarizes the factors considered in both removing authorization to discharge to Outfall 003, and continued authorization of discharges from the service water ponds to Outfall 001:

Columbia Generating Station, CGS, has two service water ponds that are available to cool the plant during emergencies and may be used as coolant during routine maintenance outages. The ponds are open, and as such, trap windblown particulates which settle onto the pond floor. Safety parameters require that the sediments in the pond not exceed a specific depth so occasionally Energy Northwest must remove sediments from the service water ponds. In the past this has been accomplished using divers who vacuum the ponds of sediment and by filtering the water to remove the suspended sediments. The sediments have a chance to contain very low levels of fallout radionuclides from the Columbia River, from the surrounding soil, and from the plant itself.

Sediment with radioactive contaminants from the plant is, by definition, considered low level waste. Because the concentrations are very low, the plant requested approval for alternate disposal of the sediments vs. sending the material to an approved low level

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 14 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 waste site. EFSEC Resolution 299 authorizes sediment from cooling water systems to be disposed into designated cells within the boundary of CGS and sets limits for radionuclide concentrations allowed in these cells based on current Hanford clean-up limits. Proper disposal of cooling tower sediments was the original purpose of Resolution 299. Upon plant closure, the final disposition of the material in these cells will be determined.

Energy Northwest is in the process of cleaning the sediment from the service water ponds. Divers have removed sediment by vacuuming the bottom of the ponds and this sediment is being disposed of per EFSEC Resolution 299 into the disposal cells. The plan was then to remove remaining sediment by filtration and backflush the filters onto the ground. The [current] NPDES permit issued by [EFSEC, WA002515-1] allows discharge of filter backwash onto the ground at a location named Outfall 003. However, the sediment within the backwash is not authorized to be placed onto the ground per EFSEC Resolution 299.

Energy Northwest has now revised its plan to remove suspended sediment in the service water ponds and has proposed to address water quality within the service water ponds by bleeding the water in the ponds into the circulating coolant water loop ('bleed and feed' process). Department of Health approves this proposal. The facility will bleed the service water into the circulating coolant water line coming from the condenser to the cooling towers. Water in the cooling towers is largely evaporated, sediments accumulate on the floors of the towers and is removed and disposed of per Resolution 299. Some of the water does return to the circulatory water pumphouse where Columbia River water is added. Occasionally service water is extracted here and discharged to the Columbia River via the monitored pathway.

The Department of Health determines the new proposal is acceptable and protective of public health and the environment for the following reasons:

1. Sediments will be disposed of via approved means (EFSEC Resolution 299)

2. Removal of suspended sediments in water will be accomplished within the normal operations of the plant. The Facility Safety Analysis Report (Chapter 9, auxiliary systems) allows for occasional release of pond water through monitored discharge line to maintain water quality in the standby service water ponds.

3. Water quality within the ponds is monitored routinely and history shows no radioactive contamination in the water above detection limits. Routine plant operations require the facility to collect monthly grab samples of service pond and analyze them for radioactive contaminants at the same detection levels required for environmental samples.

4. The service water discharge is monitored for radioactive contamination through laboratory analysis of monthly samples collected via a flow proportional sampler.

The Department of Health provides independent analysis of this monthly sample.

Stormwater runoff flows to over 100 underground injection control (UIC) wells located throughout the site. These UIC wells (and additional wells operated by Energy Northwest) are registered with Ecology under Site Number 31957. More information is available on

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 15 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Ecologys web page here: https://fortress.wa.gov/ecy/uicsearch. Specific wells authorized to receive stormwater runoff in the proposed permit are identified in the facilitys permit application.

B. Description of the receiving water Columbia Generating Station discharges to the Columbia River at river mile 351.75, and to ground water near the plant. Other nearby point source outfalls are limited by the surrounding 586 square mile Hanford Site. Significant nearby non-point sources of pollutants include discharges from agricultural areas to the east and north along the Columbia River. Nearby drinking water intakes include one for the facility approximately 700 feet upstream and those of the Cities of Richland and Pasco located approximately 12 miles downstream to the south.Section II.E of this fact sheet describes receiving waterbody impairments.

The ambient background data used for this permit includes the following from Energy Northwest Columbia Generating Station Effluent Mixing Study, June 2008:

Table 2 Ambient Background Data Parameter Value Used Temperature (highest annual 1-DADMax) 22 oC pH (geometric mean) 7.9 standard units Turbidity 0.698 NTU Hardness 61 mg/L as Ca/Mg Alkalinity 62 mg/L as CaCO3 Conductivity 126 µS/cm Ammonia 0.037 mg/L Nitrate 0.104 mg/L SO4 9.9 mg/L Lead 0.1 µg/L Copper 0.3 µg/L Chromium 0.3 µg/L Zinc 0.9 µg/L Manganese 3.1 µg/L Magnesium 4.8 mg/L

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 16 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Table 2 Ambient Background Data Parameter Value Used Fluorine 0.063 mg/L Chloride 1.0 mg/L Magnesium 4.8 mg/L C. Wastewater characterization Outfall 001 Energy Northwest reported the concentration of pollutants in the discharge in the permit application and in discharge monitoring reports. The tabulated data represents the quality of the wastewater effluent discharged from 2007 to 2013. The wastewater effluent is characterized as follows:

Table 3 Wastewater Characterization - Outfall 001 Parameter Units

1. of Samples Average Value Maximum Value Biochemical Oxygen Demand (BOD5) mg/L 1

Not Applicable (NA)

<2.0 Chemical Oxygen Demand mg/L 3

27.3 37 Total Suspended Solids (TSS) mg/L 36 11.8 33 Total Organic Carbon (TOC) mg/L 3

11.7 13 Ammonia (as N) mg/L 36 0.077 0.220 Total Residual Halogen mg/L 1000 NA

<0.11 Hardness mg/L 3

737 748 Antimony

µg/L 3

2.4 3.51 Copper, Total

µg/L 16 13.3 21.0 Chromium, Total

µg/L 38 1.093 2.8 Zinc, Total

µg/L 38 22.54 41 Lead, Total

µg/L 3

0.4 0.74 Arsenic, Total

µg/L 3

6.12 6.80

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 17 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Table 3 Wastewater Characterization - Outfall 001 Parameter Units

1. of Samples Average Value Maximum Value Selenium, Total

µg/L 3

1.86 1.94 Bromoform

µg/L 3

1.14 1.43 Mercury

µg/L 3

0.0031 0.00578 Nickel

µg/L 3

3.3 3.65 Asbestos 106 fibers/L 1

NA

<0.19 1 Halogenated waste streams are batch-released and not discharged until total residual halogen concentration complies with the effluent limit of 0.1 mg/L Parameter Units

1. of Samples Maximum Monthly Geometric Mean Maximum Weekly Geometric Mean Total Coliforms col/100 mL 1

NA 122.3 Fecal Coliforms col/100 mL 1

NA 6.8 Parameter Units

1. of Samples Minimum Value Maximum Value pH standard units Continuous 6.8 8.7 Outfall 002 Energy Northwest reported the concentration of pollutants in the discharge in the permit application and in discharge monitoring reports. The tabulated data represents the quality of the wastewater effluent discharged from 2007 to 2010. The wastewater effluent is characterized as follows:

Table 4 Wastewater Characterization - Outfall 002 Parameter Units

1. of Samples Average Value Maximum Value Flow MGD 1000 0.051 1.52 Fluoride mg/L 11 0.12 0.18 Nitrate mg/L 11 0.57 3.8

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 18 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Table 4 Wastewater Characterization - Outfall 002 Parameter Units

1. of Samples Average Value Maximum Value Nitrite mg/L 11 0.06 0.25 Gross Beta Radioactivity pCi/L 36 1.98 19.7 Sulfate mg/L 11 20.1 31 Barium, Total

µg/L 2

73 81 Iron, Total

µg/L 11 240 490 Manganese, Total

µg/L 11 13.6 280 Nickel

µg/L 11 250 410 Chromium, Total

µg/L 10 100 520 Copper, Total

µg/L 11 7

17 Zinc, Total

µg/L 10 0.0418 0.12 Lead, Total

µg/L 11

.4 1.3 Bis(2-ethylhexyl)phthalate

µg/L 3

1.04 1.62 Chloroform

µg/L 3

1.7 4.10 Chloride 1 mg/L 13 8.7 9.5 Total dissolved solids 1 mg/L 13 396.2 480 1 Chloride and Total dissolved solids data is from January 2011 through February 2012 as reported in Energy Northwest Columbia Generation Station Groundwater Quality Study Report, May 2012.

Parameter Units

1. of Samples Minimum Value Maximum Value pH standard units 10 7.2 8.3 D. Summary of compliance with previous permit issued May 25, 2006 The previous permit placed effluent limits on temperature, flow, total residual halogen, pH, copper, polychlorinated biphenyl compounds (PCBs), and the 126 priority pollutants (40 CFR 423 Appendix A) contained in chemicals added for cooling tower maintenance, except chromium and zinc.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 19 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Columbia Generating Station has complied with the effluent limits and permit conditions throughout the duration of the permit issued on May 25, 2006. EFSEC assessed compliance based on its review of the facilitys information, discharge monitoring reports (DMRs), and on inspections.

E. State environmental policy act (SEPA) compliance State law exempts the issuance, reissuance or modification of any wastewater discharge permit from the SEPA process as long as the permit contains conditions that are no less stringent than federal and state rules and regulations (RCW 43.21C.0383). The exemption applies only to existing discharges, not to new discharges. The Columbia Generating Station is an existing facility.

III. Proposed Permit Limits Federal and state regulations require that effluent limits in an NPDES permit must be either technology-or water quality-based.

• Technology-based limits are based upon the treatment methods available to treat specific pollutants. Technology-based limits are set by the EPA and published as a regulation, or EFSEC develops the limit on a case-by-case basis (40 CFR 125.3, and chapter 173-220 WAC).

• Water quality-based limits are calculated so that the effluent will comply with the Surface Water Quality Standards (chapter 173-201A WAC), Ground Water Standards (chapter 173-200 WAC), Sediment Quality Standards (chapter 173-204 WAC), or the National Toxics Rule (40 CFR 131.36).

• EFSEC must apply the most stringent of these limits to each parameter of concern. These limits are described below.

The limits in this permit reflect information received in the application and from supporting reports (engineering, hydrogeology, etc.). EFSEC evaluated the permit application and determined the limits needed to comply with the rules adopted by the state of Washington.

EFSEC does not develop effluent limits for all reported pollutants. Some pollutants are not treatable at the concentrations reported, are not controllable at the source, are not listed in regulation, and do not have a reasonable potential to cause a water quality violation.

EFSEC does not usually develop limits for pollutants not reported in the permit application but may be present in the discharge. The permit does not authorize discharge of the non-reported pollutants. During the five-year permit term, the facilitys effluent discharge conditions may change from those conditions reported in the permit application. The facility must notify EFSEC if significant changes occur in any constituent [40 CFR 122.42(a)]. Until EFSEC modifies the permit to reflect additional discharge of pollutants, a permitted facility could be violating its permit.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 20 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 A. Technology-based effluent limits EFSEC must ensure that facilities provide all known, available, and reasonable methods of prevention, control, and treatment (AKART) when it issues a permit. Technology-based effluent limitations for steam electric power generation are detailed in 40 CFR 423.

Applicable standards for Columbia Generating Station are best available technology economically achievable (BAT) standards in 40 CFR 423.13.

The following limits for total residual halogen, polychlorinated biphenyl compounds (PCBs),

and priority pollutants are based on 40 CRF 423.13. Limits for chromium, zinc, pH, and flow are based on demonstrated performance at the facility. Limits for chromium and zinc are discussed further in Section III.J.

Table 5 Technology-based Limits Parameter Average Monthly Limit Maximum Daily Limit Flow 5.6 million gallons/day (mgd) 9.4 mgd Total Residual Halogen Not applicable 0.1 milligrams/liter (mg/L)

Chromium (Total) 8.2 µg/L 16.4 µg/L Zinc (Total) 53 µg/L 107 µg/L Polychlorinated biphenyl compounds (PCBs)

No discharge No discharge The 126 priority pollutants (40 CFR 423 Appendix A) contained in chemicals added for cooling tower maintenance, except chromium and zinc No detectable amount No detectable amount Parameter Daily Minimum Daily Maximum pH 6.5 standard units 9.0 standard units Total Residual Halogen BAT effluent limits at 40 CFR 423.13(d)(1) for free available chlorine are, maximum concentration 0.5 mg/L and average 0.2 mg/L. In addition, neither free available chlorine nor total residual chlorine may be discharged from any unit for more than two hours in one day unless the utility can demonstrate to the State that the units in a particular location cannot operate at or below this level of chlorination.

The 1995 permit fact sheet documents that in March 1975, Energy Northwest requested and received a waiver of the two hour limitation, stating that it was not appropriate for recirculating water cooling systems. EFSEC later approved the use of bromine as well as chlorine biocides at the facility. Bromine has the same limit and is tested by the same procedure as chlorine. Therefore the 2006 permit includes the following limit:

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 21 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 There shall be no discharge of cooling water from Outfall 001 during biofouling treatments nor until the concentration of total residual halogens is less than 0.1 mg/L for at least 15 minutes.

The proposed permit modifies this limit to address discharges via gravity flow from the over three mile long discharge pipe that may continue even after the circulating water is isolated from the discharge pipe. The facility requested this change during entity review. EFSEC believes the proposed limit is equivalent to the current limit in preventing discharge of total residual halogen concentrations greater than or equal to 0.1 mg/L.

The circulating water blowdown valves must be closed during biofouling treatments and remain closed until the concentration of total residual halogen is less than 0.1 mg/L for at least 15 minutes.

Cooling Water Intake Structures EFSEC must ensure the location, design, construction, and capacity of cooling water intake structures reflect the best technology available for minimizing adverse environmental impact, per CWA § 316(b), 33 U.S.C. §1326(b), and 40 CFR 401.14. EPA has not promulgated final rules to establish best technology available (BTA) standards applicable to Columbia Generating Station. Until applicable BTA standards are available, 40 CFR 125.90(b) requires a case-by-case, best professional judgment (BPJ) determination of requirements.

Ecologys Permit Writers Manual provides general factors to be considered for BPJ determinations including; the appropriate technology for the category or class of the point source, and any unique factors relating to the facility. CWA § 316(b) provides specific factors for consideration including: location, design, construction, capacity, and identification of BTA for minimizing adverse environmental impact.

In addition, EPA promulgated BTA standards for new facilities at 40 CFR Subpart I in 2001, and has proposed rules for existing facilities at 40 CFR Subpart J. EFSEC considered both current rules for new facilities, even though these are not applicable to the existing Columbia Generating Station (CGS), and proposed rules for existing facilities in evaluating appropriate technology applicable to CGS. EFSEC considered correspondence from EPA, National Marine Fisheries Service (NMFS), U.S. Nuclear Regulatory Commission (NRC), and Energy Northwest in evaluating factors unique to the facility.

Location, design, and construction CGS withdraws water from the Columbia River through two 42-inch diameter inlets perforated with 3/8 inch diameter holes, each approximately 20 feet long and placed parallel to river flow approximately 350 feet offshore at low water. Water flows by gravity to the River Pumphouse.

The intake structures for CGS were designed and constructed in the late 1970s. Energy Northwest provided design and construction documents and correspondence from that time period. Correspondence documents that alternatives were considered and the final intake design was selected to minimize adverse environmental impact, specifically:

This intake was selected to minimize the impact of the make-up water withdrawal from the Columbia River, with particular emphasis on salmonid fry. Two characteristics of this

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 22 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 intake minimize fish entrainment. First, the intake location is well offshore where the number of downstream salmonid fry are expected to be relatively small. Second, the low intake approach velocities near the perforated pipe are on the order of 0.2 - 0.4 feet per second (fps).

Correspondence specific to construction indicate that the Army Corps of Engineers conditioned construction of the intakes to minimize environmental impact. Energy Northwest conducts periodic visual inspection of the intakes and has found no evidence of adverse impacts.

Capacity The term capacity is not defined in the CWA or current EPA regulations. In the 1976 Final CWA § 316(b) regulations, EPA proposed defining capacity as the maximum withdrawal rate of water through the cooling water intake structure. 41 Fed. Reg. 17390 (April 26, 1976) (proposed 40 C.F.R. § 402.11(e)). The preamble to the regulations explained that

[the] relative magnitude of flow withdrawn for cooling was one of the key factors to consider in evaluating the adverse impact from a cooling water intake structure.

CGSs average intake is approximately 20 million gallons per day (MGD) with the majority used exclusively for cooling in a closed cycle recirculating system. 40 CFR Subpart I rules for new facilities, and proposed rules for existing facilities, each set or propose BTA standards to minimize impingement and entrainment of all life stages of fish and shellfish.

Impingement occurs when fish or shellfish become entrapped on the outer part of intake screens and entrainment occurs when fish or shellfish pass through the screens and into the cooling water system.

Intake velocity is a primary factor for impingement standards with 0.5 fps identified as the maximum design intake velocity allowed by 40 CFR Subpart I. This intake velocity is also cited in the proposed existing facilities rule. Preliminary information indicates Columbia Generating Stations intake velocities are below this threshold. As indicated above, early design documents report intake velocities of 0.2 to 0.4 fps.

Entrainment standards proposed for existing facilities are either a case-by-case determination or reduction of intake flow to a level commensurate with a closed cycle recirculating system.

Columbia Generating Station already operates a closed cycle recirculating system. Energy Northwest staff provided documentation that no entrainment was observed during initial monitoring where small mesh nets designed to collect salmonid fry were placed over the intake pipes in the pump-well of the River Pumphouse. Energy Northwest also provided documentation of fish impingement surveys conducted in the late 1970s and early 1980s. No evidence of impingement was found during any of the surveys.

Economic Considerations EPA has interpreted CWA § 316(b) to authorize consideration of the cost of the technological options for cooling water intake structure improvements when making determinations of what constitutes BTA for minimizing adverse environmental impacts.

First, cost is considered in terms of whether an option is economically practicable. This can be understood as part of meeting the availability component of BTA. Second, EPA also considers costs by determining whether or not the cost of the BTA requirements would be

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 23 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 wholly disproportionate to the environmental benefit to be gained. This comparison is not a cost/benefit analysis; rather, it is a particular type of consideration of costs that EPA has determined, and the courts have upheld, is consistent with Congressional intent under CWA

§ 316(b).

EFSEC reviewed several recent permits for facilities where 40 CFR 125.90(b) is applicable.

Cost analyses reviewed often evaluated the capital costs of implementing technology options considered in the analysis, as well as some evaluation of environmental benefit. Capital costs are the direct monetary cost to the facility of implementing a particular technology. The benefit is often expressed as a reduction in volume of species either impinged or entrained in the facilities evaluated if one technology option or another is selected. This benefit can be from improved stocks of commercially valuable species or indirect social benefit.

EFSEC has found no evidence of impingement or entrainment of species from the intake structures at CGS. Therefore, no monetary or indirect social benefit can be calculated as no cost is currently incurred. Capital costs were not evaluated because no practicable technology options could be identified that would provide further minimization of adverse environmental impacts.

Best Technology Available The location, design, construction, and capacity of the cooling water intake structures at CGS were clearly chosen with the intent to provide the best technology available at the time to their construction to minimize adverse environmental impacts. EFSEC must re-evaluate these factors with each renewal of the facilitys NPDES permit. Much of the evaluation for the proposed permit is detailed above. EFSEC evaluated additional information for one specific factor, design of the intake structures.

In May 2012, the National Marine Fisheries Service (NMFS) advised EFSEC of the presence of federally protected species of steelhead and salmon in the vicinity of the intake structures.

NMFS referenced 50 CFR 223.203(b)(9) and Juvenile Fish Screen Criteria as applicable guidance on water intake systems designed to minimize adverse effects to anadromous fish. The referenced guidance document, Anadromous Salmonid Passage Facility Design, July 2011, also states:

Existing facilities may not adhere to the criteria and guidelines listed in this document.

However, that does not mean these facilities must be modified specifically for compliance with this document. The intention of these criteria and guidelines is to ensure future compliance in the context of major upgrades and new designs of fish passage facilities.

EFSEC considered these criteria and determined that, at a minimum, Energy Northwest would be required to replace the existing screens with screens containing smaller diameter (3/32 inch) perforations if the guidance were applicable to existing facilities. As a nuclear facility, modification to the intake structures would require a review of NRC safety requirements for any potential conflicts. EPAs proposed rule for existing facilities acknowledges this with a provision specific to nuclear facilities allowing for a site-specific determination of BTA that would not conflict with NRC safety requirements.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 24 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 NRC provided further information for EFSECs consideration in a December 2011 response letter to NMFS concerns on the potential take of listed species. In the letter, NRC cites three observations that led their staff to conclude in a biological assessment that the cooling system may affect, but is not likely to adversely affect both Upper Columbia River spring Chinook salmon and Upper Columbia River steelhead:

Juvenile Upper Columbia River spring Chinook are too large to be entrained into the cooling system at the time they migrate through the Hanford Reach.

Since 2006, no evidence of Upper Columbia River steelhead spawning has been observed in the Hanford Reach, and historically, steelhead fry in the Hanford Reach do not emerge until they are about 1 inch long and tend to seek cover after emergence.

Columbia Generating Station entrainment studies in 1979-1980 and 1985 collected no life stage of Upper Columbia River steelhead.

NMFS indicated in a June 2012 letter to NRC that it did not concur with NRCs determination of not likely to adversely affect ESA listed species. However, no additional information was provided. NMFS again referenced the July 2011 design guidance. EFSEC has determined that this guidance is not applicable to CGS, an existing facility, based on the applicability statement in the document itself and the absence of information indicating impingement or entrainment of listed species from the intake structures.

In February 2013, EPA requested review of a preliminary draft permit and fact sheet, which EFSEC provided in July 2013. Both EPA and NMFS provided extensive comments on the preliminary draft, which documented EFSECs best professional judgment determination that the existing cooling water intakes represent best technology available. The following requests were included in the respective comment letters:

NMFS - EFSEC should revise the proposed permit to include a requirement for Energy Northwest to work in cooperation with NMFS, the Washington State Department of Fish and Wildlife, and NRC to develop and implement a design for the intake screening system that meets NMFS juvenile fish screening criteria within two years of permit issuance.

EPA - The EPA contends that it is appropriate after 30 years since completion of the original studies of impingement and entrainment, that new studies be designed and implemented to evaluate fully the environmental impact of the CWIS. Additionally, the permit should require facility planning to evaluate the magnitude and cost of CWIS modifications needed to meet the requirements of section 316(b) and address the concerns expressed by NOAA. Studies undertaken during this permit cycle will inform whether additional actions are needed to minimizing adverse environmental impact and will support the BPJ determination for BTA. Alternately, the permittee may choose to proceed directly to the CWIS modifications to meet the objectives as described by NOAA Conclusions NMFS comments on the preliminary draft provide expert opinion that risk of impingement and entrainment to endangered species can be lowered with modification of the existing intakes in accordance with their July 2011 guidance. In response, Energy Northwest provided

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 25 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 expert opinion supporting the existing intakes as best technology available (Energy Northwest, 2013). EFSEC must consider both opinions in the context of its authorities under the CWA and federal rule for minimizing adverse environmental impact. No adverse environmental impact has been demonstrated. If it were, this must be considered along with the other factors evaluated above during BPJ analysis. EFSEC believes it has appropriately considered the potential risks identified by NMFS and EPA in the context of the BPJ analysis and its authorities under the CWA.

EFSECs best professional judgment determination is that the existing cooling water system intakes location, design, construction, and capacity represent the best technology available for minimizing adverse environmental impact and comply with CWA Section 316(b).

EFSEC will reevaluate this determination when final rules applicable to the facility are issued and may modify this proposed permit on the basis of new information. Any modifications will be implemented in accordance with the requirements of WAC 463 041, WAC 463-76-042, and WAC 463-76-043.

B. Surface water quality-based effluent limits The Washington State surface water quality standards (chapter 173-201A WAC) are designed to protect existing water quality and preserve the beneficial uses of Washington's surface waters. Waste discharge permits must include conditions that ensure the discharge will meet the surface water quality standards (WAC 173-201A-510). Water quality-based effluent limits may be based on an individual waste load allocation or on a waste load allocation developed during a basin wide total maximum daily load study (TMDL).

Numerical criteria for the protection of aquatic life and recreation Numerical water quality criteria are listed in the water quality standards for surface waters (chapter 173-201A WAC). They specify the maximum levels of pollutants allowed in receiving water to protect aquatic life and recreation in and on the water. EFSEC uses numerical criteria along with chemical and physical data for the wastewater and receiving water to derive the effluent limits in the discharge permit. When surface water quality-based limits are more stringent or potentially more stringent than technology-based limits, the discharge must meet the water quality-based limits.

Numerical criteria for the protection of human health The U.S. EPA has published 91 numeric water quality criteria for the protection of human health that are applicable to dischargers in Washington State (EPA, 1992). These criteria are designed to protect humans from exposure to pollutants linked to cancer and other diseases, based on consuming fish and shellfish and drinking contaminated surface waters. The water quality standards also include radionuclide criteria to protect humans from the effects of radioactive substances.

Narrative criteria Narrative water quality criteria (e.g., WAC 173-201A-240(1); 2006) limit the toxic, radioactive, or other deleterious material concentrations that the facility may discharge to levels below those which have the potential to:

Adversely affect designated water uses.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 26 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Cause acute or chronic toxicity to biota.

Impair aesthetic values.

Adversely affect human health.

Narrative criteria protect the specific designated uses of all fresh waters (WAC 173-201A-200, 2006) and of all marine waters (WAC 173-201A-210, 2006) in the state of Washington.

Antidegradation Description--The purpose of Washington's Antidegradation Policy (WAC 173-201A-300-330; 2006) is to:

Restore and maintain the highest possible quality of the surface waters of Washington.

Describe situations under which water quality may be lowered from its current condition.

Apply to human activities that are likely to have an impact on the water quality of surface water.

Ensure that all human activities likely to contribute to a lowering of water quality, at a minimum, apply all known, available, and reasonable methods of prevention, control, and treatment (AKART).

Apply three tiers of protection (described below) for surface waters of the state.

Tier I ensures existing and designated uses are maintained and protected and applies to all waters and all sources of pollutions. Tier II ensures that waters of a higher quality than the criteria assigned are not degraded unless such lowering of water quality is necessary and in the overriding public interest. Tier II applies only to a specific list of polluting activities.

Tier III prevents the degradation of waters formally listed as "outstanding resource waters,"

and applies to all sources of pollution.

A facility must prepare a Tier II analysis when all three of the following conditions are met:

The facility is planning a new or expanded action.

EFSEC regulates or authorizes the action.

The action has the potential to cause measurable degradation to existing water quality at the edge of a chronic mixing zone.

Facility Specific Requirements--This facility must meet Tier I requirements.

Dischargers must maintain and protect existing and designated uses. EFSEC must not allow any degradation that will interfere with, or become injurious to, existing or designated uses, except as provided for in chapter 173-201A WAC.

EFSECs analysis described in this section of the fact sheet demonstrates that the proposed permit conditions will protect existing and designated uses of the receiving water.

Mixing zones A mixing zone is the defined area in the receiving water surrounding the discharge port(s),

where wastewater mixes with receiving water. Within mixing zones the pollutant

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 27 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 concentrations may exceed water quality numeric standards, so long as the discharge doesnt interfere with designated uses of the receiving water body (for example, recreation, water supply, and aquatic life and wildlife habitat, etc.) The pollutant concentrations outside of the mixing zones must meet water quality numeric standards.

State and federal rules allow mixing zones because the concentrations and effects of most pollutants diminish rapidly after discharge, due to dilution. EFSEC defines mixing zone sizes to limit the amount of time any exposure to the end-of-pipe discharge could harm water quality, plants, or fish.

The states water quality standards allow EFSEC to authorize mixing zones for the facilitys permitted wastewater discharges only if those discharges already receive all known, available, and reasonable methods of prevention, control, and treatment (AKART). Mixing zones typically require compliance with water quality criteria within a specified distance from the point of discharge and must not use more than 25% of the available width of the water body for dilution [WAC 173-201A-400 (7)(a)(ii-iii)].

EFSEC uses modeling to estimate the amount of mixing within the mixing zone. Through modeling EFSEC determines the potential for violating the water quality standards at the edge of the mixing zone and derives any necessary effluent limits. Steady-state models are the most frequently used tools for conducting mixing zone analyses. EFSEC chooses values for each effluent and for receiving water variables that correspond to the time period when the most critical condition is likely to occur (see Ecologys Permit Writers Manual). Each critical condition parameter, by itself, has a low probability of occurrence and the resulting dilution factor is conservative. The term reasonable worst-case applies to these values.

The mixing zone analysis produces a numerical value called a dilution factor (DF). A dilution factor represents the amount of mixing of effluent and receiving water that occurs at the boundary of the mixing zone. For example, a dilution factor of 10 means the effluent is 10% and the receiving water is 90% of the total volume of water at the boundary of the mixing zone. EFSEC uses dilution factors with the water quality criteria to calculate reasonable potentials and effluent limits. Water quality standards include both aquatic life-based criteria and human health-based criteria. The former are applied at both the acute and chronic mixing zone boundaries; the latter are applied only at the chronic boundary. The concentration of pollutants at the boundaries of any of these mixing zones may not exceed the numerical criteria for that zone.

Each aquatic life acute criterion is based on the assumption that organisms are not exposed to that concentration for more than one hour and more often than one exposure in three years.

Each aquatic life chronic criterion is based on the assumption that organisms are not exposed to that concentration for more than four consecutive days and more often than once in three years.

The two types of human health-based water quality criteria distinguish between those pollutants linked to non-cancer effects (non-carcinogenic) and those linked to cancer effects (carcinogenic). The human health-based water quality criteria incorporate several exposure and risk assumptions. These assumptions include:

A 70-year lifetime of daily exposures.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 28 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 An ingestion rate for fish or shellfish measured in kg/day.

An ingestion rate of two liters/day for drinking water.

A one-in-one-million cancer risk for carcinogenic chemicals.

This permit authorizes a small acute mixing zone, surrounded by a chronic mixing zone around the point of discharge (WAC 173-201A-400). The water quality standards impose certain conditions before allowing the discharger a mixing zone:

1. EFSEC must specify both the allowed size and location in a permit.

The proposed permit specifies the size and location of the allowed mixing zone (as specified below).

2. The facility must fully apply all known, available, and reasonable methods of prevention, control and treatment (AKART) to its discharge.

EFSEC has determined that the treatment provided at Columbia Generating Station meets the requirements of AKART (see Technology-based Limits).

3. EFSEC must consider critical discharge conditions.

Surface water quality-based limits are derived for the water bodys critical condition (the receiving water and waste discharge condition with the highest potential for adverse impact on the aquatic biota, human health, and existing or designated waterbody uses). The critical discharge condition is often pollutant-specific or waterbody-specific.

Critical discharge conditions are those conditions that result in reduced dilution or increased effect of the pollutant. Factors affecting dilution include the depth of water, the density stratification in the water column, the currents, and the rate of discharge. Density stratification is determined by the salinity and temperature of the receiving water.

Temperatures are warmer in the surface waters in summer. Therefore, density stratification is generally greatest during the summer months. Density stratification affects how far up in the water column a freshwater plume may rise. The rate of mixing is greatest when an effluent is rising. The effluent stops rising when the mixed effluent is the same density as the surrounding water. After the effluent stops rising, the rate of mixing is much more gradual.

Water depth can affect dilution when a plume might rise to the surface when there is little or no stratification. Ecologys Permit Writers Manual describes additional guidance on criteria/design conditions for determining dilution factors. The manual can be obtained from Ecologys website at: https://fortress.wa.gov/ecy/publications/SummaryPages/92109.html.

Table 6 Critical Conditions Used to Model the Discharge Critical Condition Value The seven-day-average low river flow with a recurrence interval of ten years (7Q10) 52,700 cubic feet per second (cfs)

River depth at the 7Q10 period 8.5 feet River velocity 5.35 ft per second

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 29 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Table 6 Critical Conditions Used to Model the Discharge Critical Condition Value Manning roughness coefficient 0.02 Channel width 1,400 feet Maximum average monthly effluent flow for chronic and human health non-carcinogen 4.3 MGD Annual average flow for human health carcinogen 2.4 MGD Maximum daily flow for acute mixing zone 5.9 million gallons per day (MGD) 1-DAD MAX Effluent temperature 29.6 degrees C EFSEC obtained ambient data at critical conditions in the vicinity of the outfall from the permit application, DMRs, and the Energy Northwest Columbia Generating Station Effluent Mixing Study conducted in 2008.

4. Supporting information must clearly indicate the mixing zone would not:

Have a reasonable potential to cause the loss of sensitive or important habitat.

Substantially interfere with the existing or characteristic uses.

Result in damage to the ecosystem.

Adversely affect public health.

Ecology established Washington State water quality criteria for toxic chemicals using EPA criteria. EPA developed the criteria using toxicity tests with numerous organisms and set the criteria to generally protect the species tested and to fully protect all commercially and recreationally important species.

EPA sets acute criteria for toxic chemicals assuming organisms are exposed to the pollutant at the criteria concentration for one hour. EPA sets chronic standards assuming organisms are exposed to the pollutant at the criteria concentration for four days. Dilution modeling under critical conditions generally shows that both acute and chronic criteria concentrations are reached within minutes of discharge.

The discharge plume does not impact drifting and non-strong swimming organisms because they cannot stay in the plume close to the outfall long enough to be affected. Strong swimming fish could maintain a position within the plume, but they can also avoid the discharge by swimming away. Mixing zones generally do not affect benthic organisms (bottom dwellers) because the buoyant plume rises in the water column. EFSEC has additionally determined that the effluent will not exceed 33 degrees C for more than two seconds after discharge; and that the temperature of the water will not create lethal conditions or blockages to fish migration.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 30 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 EFSEC evaluates the cumulative toxicity of an effluent by testing the discharge with whole effluent toxicity (WET) testing.

EFSEC reviewed the above information, the specific information on the characteristics of the discharge, the receiving water characteristics and the discharge location. Based on this review, EFSEC concluded that the discharge does not have a reasonable potential to cause the loss of sensitive or important habitat, substantially interfere with existing or characteristics uses, result in damage to the ecosystem, or adversely affect public health if the permit limits are met.

5. The discharge/receiving water mixture must not exceed water quality criteria outside the boundary of a mixing zone.

EFSEC conducted a reasonable potential analysis, using procedures established by the EPA and by Ecology, for each pollutant and concluded the discharge/receiving water mixture will not violate water quality criteria outside the boundary of the mixing zone if permit limits are met.

6. The size of the mixing zone and the concentrations of the pollutants must be minimized.

At any given time, the effluent plume uses only a portion of the acute and chronic mixing zone, which minimizes the volume of water involved in mixing. The plume mixes as it rises through the water column therefore much of the receiving water volume at lower depths in the mixing zone is not mixed with discharge. Similarly, because the discharge may stop rising at some depth due to density stratification, waters above that depth will not mix with the discharge. EFSEC determined it is impractical to specify in the permit the actual, much more limited volume in which the dilution occurs as the plume rises and moves with the current.

EFSEC minimizes the size of mixing zones by requiring dischargers to install diffusers when they are appropriate to the discharge and the specific receiving waterbody. When a diffuser is installed, the discharge is more completely mixed with the receiving water in a shorter time. EFSEC also minimizes the size of the mixing zone (in the form of the dilution factor) using design criteria with a low probability of occurrence. For example, EFSEC uses the expected 95th percentile pollutant concentration, the 90th percentile background concentration, the centerline dilution factor, and the lowest flow occurring once in every ten years to perform the reasonable potential analysis.

Because of the above reasons, EFSEC has effectively minimized the size of the mixing zone authorized in the proposed permit.

7. Maximum size of mixing zone.

The authorized mixing zone does not exceed the maximum size restriction.

8. Acute mixing zone.

The discharge/receiving water mixture must comply with acute criteria as near to the point of discharge as practicably attainable.

EFSEC determined the acute criteria will be met at 10% of the distance of the chronic mixing zone at the ten year low flow.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 31 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 The pollutant concentration, duration, and frequency of exposure to the discharge will not create a barrier to migration or translocation of indigenous organisms to a degree that has the potential to cause damage to the ecosystem.

As described above, the toxicity of any pollutant depends upon the exposure, the pollutant concentration, and the time the organism is exposed to that concentration. Authorizing a limited acute mixing zone for this discharge assures that it will not create a barrier to migration. The effluent from this discharge will rise as it enters the receiving water, assuring that the rising effluent will not cause translocation of indigenous organisms near the point of discharge (below the rising effluent).

Comply with size restrictions.

The mixing zone authorized for this discharge complies with the size restrictions published in chapter 173-201A WAC.

9. Overlap of Mixing Zones.

This mixing zone does not overlap another mixing zone.

C. Designated uses and surface water quality criteria Applicable designated uses and surface water quality criteria are defined in chapter 173-201A WAC. In addition, the U.S. EPA set human health criteria for toxic pollutants (EPA 1992). The table included below summarizes the criteria applicable to this facilitys discharge.

Aquatic Life Uses are designated based on the presence of, or the intent to provide protection for the key uses. All indigenous fish and non-fish aquatic species must be protected in waters of the state in addition to the key species. The Aquatic Life Uses for this receiving water are identified below.

Table 7 Freshwater Aquatic Life Uses and Associated Criteria Salmonid Spawning, Rearing, and Migration Temperature Criteria DMax1 20°C (68°F)

Temperature must not exceed a 1-DMax of 20.0º C due to human activities. When natural conditions exceed a 1-DMax of 20.0 C, no temperature increase will be allowed which will raise the receiving water temperature by greater than 0.3 C; nor shall such temperature increases, at any time, exceed t = 34/(T + 9).

Dissolved Oxygen Criteria - Lowest 1-Day Minimum 8.0 mg/L Turbidity Criteria 5 NTU over background when the background is 50 NTU or less; or A 10 percent increase in turbidity when the background turbidity is more than 50 NTU.

Total Dissolved Gas Criteria Total dissolved gas must not exceed 110 percent of saturation at any point of sample collection.

pH Criteria The pH must measure within the range of 6.5 to 8.5 with a human-caused variation within the above range of less than 0.5 units.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 32 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 1WAC 172-201A-602 establishes a special condition for the Columbia River in the vicinity of Columbia Generating Station Outfall 001.

The recreational uses for this receiving water are identified below.

Table 8 Recreational Uses and Associated Criteria Recreational Use Criteria Primary Contact Recreation Fecal coliform organism levels must not exceed a geometric mean value of 100 colonies /100 mL, with not more than 10 percent of all samples (or any single sample when less than ten sample points exist) obtained for calculating the geometric mean value exceeding 200 colonies /100 mL.

The water supply uses are domestic, agricultural, industrial, and stock watering.

The miscellaneous freshwater uses are wildlife habitat, harvesting, commerce and navigation, boating, and aesthetics.

D. Water quality impairments The Columbia River is listed on the current 303(d) and is impaired for dioxin and total dissolved gas. Ecology has completed a Total Maximum Daily Load (TMDL) Analysis for dioxin (https://fortress.wa.gov/ecy/publications/SummaryPages/0910058.html) and total dissolved gas (https://fortress.wa.gov/ecy/publications/summarypages/0403002.html).

Ecology has not documented temperature impairment in the receiving water in the vicinity of the outfall however Ecology considers the entire Columbia River impaired for temperature.

EPA has prepared a draft TMDL for temperature. However, EPA has delayed issuance pending discussion and information exchanges.

E. Evaluation of surface water quality-based effluent limits for numeric criteria Pollutants in an effluent may affect the aquatic environment near the point of discharge (near-field) or at a considerable distance from the point of discharge (far-field). Toxic pollutants, for example, are near-field pollutants; their adverse effects diminish rapidly with mixing in the receiving water. Conversely, a pollutant such as biological oxygen demand (BOD) is a far-field pollutant whose adverse effect occurs away from the discharge even after dilution has occurred. Thus, the method of calculating surface water quality-based effluent limits varies with the point at which the pollutant has its maximum effect.

With technology-based controls (AKART), predicted pollutant concentrations in the discharge exceed water quality criteria. EFSEC therefore authorizes a mixing zone in accordance with the geometric configuration, flow restriction, and other restrictions imposed on mixing zones by chapter 173-201A WAC.

The diffuser at Outfall 001 is a single port structure aligned perpendicular to the river flow, is 8 inches in height, 32 inches wide, and extends upward from the river bed at a 15º angle. The diffuser depth is 8.5 feet at critical condition flow. EFSEC obtained this information from the Energy Northwest Columbia Generating Station Effluent Mixing Study, June 2008.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 33 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Figure 3 Columbia Generating Station Regulatory Mixing Zone Chronic Mixing Zone--WAC 173-201A-400(7)(a) specifies that mixing zones must not extend in a downstream direction from the discharge ports for a distance greater than 300 feet plus the depth of water over the discharge ports or extend upstream for a distance of over 100 feet, not utilize greater than 25% of the flow, and not occupy greater than 25% of the width of the water body.

The horizontal distance of the chronic mixing zone is 308 feet. The mixing zone extends from the top of the discharge port to the water surface.

Acute Mixing Zone--WAC 173-201A-400(8)(a) specifies that in rivers and streams a zone where acute toxics criteria may be exceeded must not extend beyond 10% of the distance towards the upstream and downstream boundaries of the chronic zone, not use greater than 2.5% of the flow and not occupy greater than 25% of the width of the water body.

The horizontal distance of the acute mixing zone is 31 feet. The mixing zone extends from the top of the discharge port to the water surface. The dilution factor is based on this distance.

EFSEC determined the dilution factors that occur within these zones at the critical condition based on review of the Energy Northwest Columbia Generating Station Effluent Mixing Study, June 2008. Ecologys Permit Writers Manual gives critical flow conditions for human health criteria as the harmonic mean flow for carcinogens and 30Q5 for non-carcinogens.

The study did not evaluate these conditions. Therefore, EFSEC used dilution factors determined for aquatic life criteria as conservative estimates for human health criteria.

Plan View - not to scale 7Q10 flow = 52,700 cfs River width = 1,400 ft.

Outfall port is 8 inches high and 32 inches wide Located approximately 175 feet from bank at a depth of 8.5 feet at the critical conditions.

Dilution Zone = 308 feet Acute Zone = 31 feet Width of plume = 20 feet Max. = 100 ft.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 34 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 The study used the CORMIX Hydrodynamic Mixing Zone Model (CORMIX1 - Version 5.0). Energy Northwest also conducted an in-situ tracer study using forward looking infrared (FLIR) technology focusing on temperature as a dilution tracer. The dilution factors are listed below.

Table 9 Dilution Factors (DF)

Criteria Acute Chronic Aquatic Life 9

93 Human Health, Carcinogen Not evaluated, therefore 93 was used Human Health, Non-carcinogen Not evaluated, therefore 93 was used EFSEC determined the impacts of pH, turbidity, ammonia, chlorine, chromium, copper, zinc, and temperature as described below, using the dilution factors in the above table. The derivation of surface water quality-based limits also takes into account the variability of pollutant concentrations in both the effluent and the receiving water.

pH--EFSEC modeled the impact of the effluent pH on the receiving water using the calculations from EPA, 1988, and the chronic dilution factor tabulated above. Appendix D includes the model results.

EFSEC predicts no violation of the pH criteria under critical conditions. Therefore, the proposed permit includes technology-based effluent limits for pH. Because the facility has demonstrated it can meet previous permit limits of 6.5 to 9.0, the proposed permit includes the technology-based effluent limits for pH of a pH range of 6.5 to 9.0 on the basis of best professional judgment (BPJ).

Turbidity--EFSEC evaluated the impact of turbidity based on the range of turbidity in the effluent and turbidity of the receiving water. Based on visual observation of the facilitys effluent, EFSEC expects no violations of the turbidity criteria outside the designated mixing zone.

Toxic Pollutants--Federal regulations (40 CFR 122.44) require EFSEC to place limits in NPDES permits on toxic chemicals in an effluent whenever there is a reasonable potential for those chemicals to exceed the surface water quality criteria. EFSEC does not exempt facilities with technology-based effluent limits from meeting the surface water quality standards.

The following toxic pollutants are present in the discharge: ammonia, chlorine, chromium, copper, bromoform, zinc, antimony, arsenic, lead, mercury, nickel, and selenium. EFSEC conducted a reasonable potential analysis (See Appendix D) on these parameters to determine whether it would require effluent limits in this permit.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 35 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Ammonia's toxicity depends on that portion which is available in the unionized form. The amount of unionized ammonia depends on the temperature and pH in the receiving freshwater. To evaluate ammonia toxicity, EFSEC used the available receiving water information for the effluent mixing study and Ecology spreadsheet tools.

Valid ambient background data were available for ammonia, chlorine, chromium, copper, lead, and zinc (See Table 2). EFSEC used all applicable data to evaluate reasonable potential for this discharge to cause a violation of water quality standards.

EFSEC determined that ammonia, chlorine, chromium, copper, bromoform, zinc, antimony, arsenic, lead, mercury, nickel, and selenium pose no reasonable potential to exceed the water quality criteria at the critical condition using procedures given in EPA, 1991 (Appendix D) and as described above. EFSECs determination assumes that this facility meets the other effluent limits of this permit.

Temperature--The state temperature standards (WAC 173-201A-200-210 and 600-612) include multiple elements:

Annual summer maximum threshold criteria (June 15 to September 15)

Supplemental spawning and rearing season criteria (September 15 to June 15)

Incremental warming restrictions Protections against acute effects EFSEC evaluates each criterion independently to determine reasonable potential and derive permit limits.

Annual summer maximum and supplementary spawning/rearing criteria Each water body has an annual maximum temperature criterion [WAC 173-201A-200(1)(c),

210(1)(c), and Table 602]. These threshold criteria (e.g., 12, 16, 17.5, 20°C) protect specific categories of aquatic life by controlling the effect of human actions on summer temperatures.

Some waters have an additional threshold criterion to protect the spawning and incubation of salmonids (9°C for char and 13°C for salmon and trout) [WAC 173-201A-602, Table 602].

These criteria apply during specific date-windows.

The threshold criteria apply at the edge of the chronic mixing zone. Criteria for most fresh waters are expressed as the highest 7-Day average of daily maximum temperature (7-DADMax). The 7-DADMax temperature is the arithmetic average of seven consecutive measures of daily maximum temperatures. Criteria for marine waters and some fresh waters are expressed as the highest 1-Day annual maximum temperature (1-DMax).

Incremental warming criteria The water quality standards limit the amount of warming human sources can cause under specific situations [WAC 173-201A-200(1)(c)(i)-(ii), 210(1)(c)(i)-(ii)]. The incremental warming criteria apply at the edge of the chronic mixing zone.

At locations and times when background temperatures are cooler than the assigned threshold criterion, point sources are permitted to warm the water by only a defined increment. These

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 36 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 increments are permitted only to the extent doing so does not cause temperatures to exceed either the annual maximum or supplemental spawning criteria.

At locations and times when a threshold criterion is being exceeded due to natural conditions, all human sources, considered cumulatively, must not warm the water more than 0.3°C above the naturally warm condition.

When Ecology has not yet completed a TMDL, our policy allows each point source to warm water at the edge of the chronic mixing zone by 0.3°C. This is true regardless of the background temperature and even if doing so would cause the temperature at the edge of a standard mixing zone to exceed the numeric threshold criteria. Allowing a 0.3°C warming for each point source is reasonable and protective where the dilution factor is based on 25%

or less of the critical flow. This is because the fully mixed effect on temperature will only be a fraction of the 0.3°C cumulative allowance (0.075°C or less) for all human sources combined.

Protections for temperature acute effects Instantaneous lethality to passing fish: The upper 99th percentile daily maximum effluent temperature must not exceed 33°C, unless a dilution analysis indicates ambient temperatures will not exceed 33°C two seconds after discharge.

General lethality and migration blockage: Measurable (0.3°C) increases in temperature at the edge of a chronic mixing zone are not allowed when the receiving water temperature exceeds either a 1DMax of 23°C or a 7DADMax of 22°C.

Lethality to incubating fish: Human actions must not cause a measurable (0.3°C) warming above 17.5°C at locations where eggs are incubating.

Reasonable Potential Analysis Annual summer maximum and incremental warming criteria: EFSEC calculated the reasonable potential for the discharge to exceed the annual summer maximum and the incremental warming criteria at the edge of the chronic mixing zone during critical conditions. No reasonable potential exists to exceed the temperature criterion where:

(Criterion + 0.3) > [Criterion + (Teffluent95 - Criterion)/DF]

The figure below graphically portrays the above equation and shows the conditions when a permit limit will apply.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 37 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Figure 4 Dilution Necessary to Meet Criteria at Edge of Mixing Zone Columbia Generating Station Outfall 001 data input to the above equation yields the following:

(20 + 0.3) > [20 + (34.9 - 20)/93] or 20.3 > 20.2 Therefore, the proposed permit does not include a temperature limit. The permit requires additional monitoring of effluent temperatures. EFSEC will reevaluate the reasonable potential during the next permit renewal.

Instantaneous lethality to passing fish: Near-field dilution analysis demonstrates that the plume temperature is less than 33°C two seconds after discharge. EFSEC calculated the plume temperature two seconds after discharge using the equations shown in Appendix D.

The results demonstrate there is no reasonable potential for instantaneous lethality to passing fish.

F. Human health Washingtons water quality standards include 91 numeric human health-based criteria that EFSEC must consider when writing NPDES permits. These criteria were established in 1992 by the U.S. EPA in its National Toxics Rule (40 CFR 131.36). The National Toxics Rule allows states to use mixing zones to evaluate whether discharges comply with human health criteria.

EFSEC determined the effluent may contain chemicals of concern for human health, based on the facilitys status as an EPA major discharger, and data or information indicating the discharge contains regulated chemicals.

EFSEC evaluated the discharge's potential to violate the water quality standards as required by 40 CFR 122.44(d) by following the procedures published in the Technical Support Document for Water Quality-Based Toxics Control (EPA/505/2-90-001) and Ecology's Permit Writer's Manual to make a reasonable potential determination. The evaluation 0

10 20 30 40 50 17 19 21 23 25 27 29 31 33 Minimum Chronic Dilution Factor needed to meet numeric WQ criteria 95th Percentile Effluent Temperature, °C WQ Criteria =

17.5 WQ Criteria = 18 WQ Criteria = 19 WQ Criteria = 20 Calculation based on:

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 38 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 showed that the discharge has no reasonable potential to cause a violation of water quality standards, and an effluent limit is not needed.

G. Sediment quality The aquatic sediment standards (chapter 173-204 WAC) protect aquatic biota and human health. Under these standards EFSEC may require a facility to evaluate the potential for its discharge to cause a violation of sediment standards (WAC 173-204-400). You can obtain additional information about sediments at the Aquatic Lands Cleanup Unit website.

http://www.ecy.wa.gov/programs/tcp/smu/sediment.html Through a review of the discharger characteristics and of the effluent characteristics, EFSEC determined that this discharge has no reasonable potential to violate the sediment management standards. This determination is based on the low concentrations of TSS in the discharge, and that the velocity of the Columbia River in the vicinity of the outfall inhibits deposition. This was confirmed in the results of an October 2006 outfall evaluation where sediment deposition was found to be minimal if not non-existent downstream of the outfall.

H. Groundwater quality limits The groundwater quality standards (chapter 173-200 WAC) protect beneficial uses of groundwater. Permits issued by EFSEC must not allow violations of those standards (WAC 173-200-100).

Implementation Guidance for the Ground Water Quality Standards (Ecology Publication

1. 96-02) provides guidance for how enforcement limits are determined. The procedure requires a minimum of eight sampling events to establish background. The background monitoring well must be upgradient of the activity and not impacted by facility discharge.

The 2006 permit required Energy Northwest to conduct a groundwater quality study. EFSEC reviewed the Energy Northwest Columbia Generation Station Groundwater Quality Study Report, May 2012 and determined that the upgradient well for Outfall 002 (MW-9) is impacted by facility discharge and cannot be used as an upgradient well for the purposes of determining impacts to groundwater. While discussing options determining compliance with groundwater quality standards, Energy Northwest indicated a commitment to installing a double-lined evaporation pond with leak detection to replace Outfall 002.

The proposed permit includes a compliance schedule for installation of a double lined evaporation pond. Therefore, continued groundwater monitoring to establish limits for Outfall 002 is unnecessary because the facility will no longer discharge to ground following completion of the pond. However, groundwater monitoring to determine the effects of removing this discharge is necessary. The current groundwater mound under Outfall 002 is expected to recede when discharges cease. Outfall 002 monitoring wells are downgradient from Hanford 618-11 burial ground. Contamination from that burial ground may have been pushed around the mound and not detected. When the mound dissipates, contaminants may be detected in MW-9. EFSEC expects continued monitoring to be addressed in the Ground Water Quality Study Quality Assurance Project Plan (QAPP) update required in S7.5 of the proposed permit.

More information about the compliance schedule for groundwater quality activities is presented in Section V.H of this fact sheet.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 39 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 I. Whole effluent toxicity The water quality standards for surface waters forbid discharge of effluent that has the potential to cause toxic effects in the receiving waters. Many toxic pollutants cannot be measured by commonly available detection methods. However, laboratory tests can measure toxicity directly by exposing living organisms to the wastewater and measuring their responses. These tests measure the aggregate toxicity of the whole effluent, so this approach is called whole effluent toxicity (WET) testing. Some WET tests measure acute toxicity and other WET tests measure chronic toxicity.

Acute toxicity tests measure mortality as the significant response to the toxicity of the effluent. Dischargers who monitor their wastewater with acute toxicity tests find early indications of any potential lethal effect of the effluent on organisms in the receiving water.

Chronic toxicity tests measure various sublethal toxic responses, such as reduced growth or reproduction. Chronic toxicity tests often involve either a complete life cycle test on an organism with an extremely short life cycle, or a partial life cycle test during a critical stage of a test organism's life. Some chronic toxicity tests also measure survival.

Laboratories accredited by Ecology for WET testing know how to use the proper WET testing protocols, fulfill the data requirements, and submit results in the correct reporting format. Accredited laboratory staff know how to calculate an NOEC, LC50, EC50, IC25, etc. Ecology gives all accredited labs the most recent version of Ecology Publication No.

WQ-R-95-80, Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria (https://fortress.wa.gov/ecy/publications/SummaryPages/9580.html) which is referenced in the permit. EFSEC recommends that Columbia Generating Station send a copy of the acute or chronic toxicity sections(s) of its NPDES permit to the laboratory.

WET testing conducted during effluent characterization showed no reasonable potential for effluent discharges to cause receiving water acute or chronic toxicity. The proposed permit will not include an acute or chronic WET limit. Columbia Generating Station must retest the effluent before submitting an application for permit renewal.

If this facility makes process or material changes which, in EFSEC's opinion, increase the potential for effluent toxicity, then EFSEC may (in a regulatory order, by permit modification, or in the permit renewal) require the facility to conduct additional effluent characterization. Columbia Generating Station may demonstrate to EFSEC that effluent toxicity has not increased by performing additional WET testing and/or chemical analyses after the process or material changes have been made. EFSEC recommends that the Permittee check with it first to make sure that EFSEC will consider the demonstration adequate to support a decision to not require an additional effluent characterization.

If WET testing conducted for submittal with a permit application fails to meet the performance standards in WAC 173-205-020, EFSEC will assume that effluent toxicity has increased.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 40 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 J. Comparison of effluent limits with previous permit issued May 25, 2006 Table 10 Comparison of Previous and Proposed Effluent Limits Previous Effluent Limits:

Outfall # 001 Proposed Effluent Limits:

Outfall # 001 Parameter Basis of Limit Average Monthly Maximum Daily Average Monthly Maximum Daily Flow (mgd)

Technology 5.6 9.4 5.6 9.4 Temperature Technology Not applicable (NA)

(Note 1)

NA Total Residual Halogen (mg/L)

Technology NA 0.1 NA 0.1 Total Copper (Dec. -

Feb.) (µg/L)

Water Quality 70 108 NA NA Total Copper (Mar. -

Nov.) (µg/L)

Water Quality 223 345 Total Chromium (µg/L)

Technology 8.2 16.4 Total Zinc (µg/L)

Technology 53 107 Polychlorinated biphenyl compounds (PCBs)

Technology No discharge No discharge No discharge No discharge The 126 priority pollutants (40 CFR 423 Appendix A) contained in chemicals added for cooling tower maintenance, except chromium and zinc Technology No detectable amount No detectable amount No detectable amount No detectable amount Parameter Basis of Limit Limit Limit pH Technology Between 6.5 - 9.0 at all times Between 6.5 - 9.0 at all times 1The temperature of the circulating cooling water blowdown shall not exceed, at any time, the lowest temperature of the circulating cooling water, prior to the addition of makeup water, except that the temperature of the blowdown may be less than the temperature of the river.

Temperature EFSEC evaluated the temperature limit from previous permits (see footnote to Table 11) and determined that it is based on an outdated version of federal rule. The 1995 permit fact sheet cites Federal Register, Vol. 39, No. 196 as the basis for the technology-based effluent limit for temperature. A 1974 version of 40 CFR 423.13(l)(1) contained this limitation. However, subsequent amendments to 40 CFR 423.13 removed limitations for temperature in 1982. In addition, previous permits did not contain sufficient monitoring requirements to verify the narrative temperature limit.

The proposed permit removes this technology-based temperature limit. EFSEC does not believe removal of this limit results in less stringent requirements. Temperature monitoring during

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 41 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 previous permit terms and the 2006 permit term occurs just past the isolation valve for the blowdown line. This is identified in Section 5.0 of the Columbia Generating Station NPDES Operations and Maintenance Plan, March 2012, as the lowest temperature point in the circulating cooling water system. In addition, S4.B of the proposed permit prohibits bypass of any portion of the treatment system. If Energy Northwest proposes to relocate the blowdown line withdrawal location to another point in the circulating cooling water system, EFSEC will reevaluate the need for a temperature limit and may modify the permit in accordance with G.3 Permit actions.

EFSEC also evaluated the need for water quality-based limits in Section III.E above and found that no reasonable potential exists to exceed the temperature criterion. EFSEC based the evaluation on data collected at the current temperature monitoring location in the Circulating Pumphouse, adjacent to the cooling towers. The effluent travels over three miles through a vented discharge pipe after passing the existing monitoring location. Therefore, temperatures may not be representative of the actual discharge and are likely to be less than currently reported.

The proposed permit requires Energy Northwest to continue monitoring effluent temperature and to relocate the monitoring device to the facilitys River Pumphouse, adjacent to the actual discharge to the Columbia River. EFSEC will reevaluate the reasonable potential during the next permit renewal.

Copper Copper is not contained in any of the chemicals added for cooling system maintenance and there are no categorical limits for copper in 40 CFR 423. However, the facility detected copper in the discharge in concentrations higher than the receiving water criteria during the previous permit term. A suspected major source was corrosion of the admiralty brass components of the main steam condenser. Energy Northwest replaced the copper condenser tubes in September 2011 with titanium.

The 2006 permit retained interim copper limits from the 1995 permit and required Energy Northwest to conduct an effluent mixing study and, as necessary, propose numeric effluent limits. Mixing study analysis showed no reasonable potential for copper to exceed water quality criteria. This analysis included effluent values for copper observed prior to condenser replacement. Using both pre and post condenser replacement effluent values for copper, EFSEC also determined that copper poses no reasonable potential to exceed the water quality criteria at the critical condition using procedures given in EPA, 1991 (Appendix D).

Federal requirements at CWA 402(o), CWA 303(d)(4), and 40 CFR 122.44(l) prohibit less stringent water-quality effluent limits in renewed or reissued permits, with few exceptions. One exception noted in 40 CFR 122.44(l)(2)(i)(A) is when material and substantial alterations to the facility occur after permit issuance that justify a less stringent limit. EFSEC determined that replacement of the condenser constitutes a material and substantial alteration to the facility. The proposed permit does not include a water quality based effluent limit for copper. It does include continued monthly monitoring for copper. EFSEC will reevaluate the reasonable potential for copper during the next permit renewal.

Chromium and Zinc

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 42 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 The 2006 permit fact sheet described the requirement for inclusion of applicable technology-based effluent limits for chromium and zinc (WAC 173-220-130 and 40 CFR 125.3). However, the permit failed to include limits. EPA has established and promulgated technology-based effluent limit guidelines for steam electric power generating at 40 CFR 423. Applicable standards for Columbia Generating Station are best available technology economically achievable (BAT) standards in 40 CFR 423.13.

40 CFR 122.44(l) prohibits less stringent technology-based effluent limits in renewed or reissued permits, with few exceptions. One exception is if the change would constitute a cause for permit modification or revocation and reissuance under 40 CFR 122.62. EFSEC believes the failure to include applicable technology-based effluent limits for chromium and zinc in the previous permit meets the cause for modification in 40 CFR 122.62(a)(15): To correct technical mistakes, such as errors in calculation, or mistaken interpretations of law made in determining permit conditions.

EFSEC evaluated the applicable BAT standards for chromium, 200 µg/L, and zinc, 1,000 µg/L for inclusion in the proposed permit as required by 40 CFR 125.3. Effluent discharged at these limits would violate applicable water quality criteria for both parameters. EFSEC cannot propose limits that would result in a violation of water quality criteria.

EFSEC determined that both chromium and zinc pose no reasonable potential to exceed the water quality criteria at the critical condition using procedures given in EPA, 1991 (Appendix D). EFSEC used total chromium effluent values in the analysis as a conservative substitute for hexavalent chromium, the most restrictive applicable water quality criteria.

Because EFSEC cannot include the BAT standards, the proposed permit incorporates average monthly and daily maximum limits based on best professional judgment. EFSEC elected not to use the procedures to calculate performance-based limits because many of the samples contained no detectable chromium which complicates the analysis. Instead, EFSEC used procedures given in EPA, 1991 (Appendix D) to calculate effluent limits where water quality standards are met at end-of-pipe. Monitoring data from the facility demonstrates that it is capable of consistently meeting the proposed limits without an allowance for mixing. Therefore, EFSEC is imposing these limits as technology-based limits in lieu of the BAT standards. Although calculated using the techniques for human health criteria permit limits, EFSEC is imposing these limits based on its best professional judgment. The limits are not water quality-based limits.

IV. Monitoring Requirements EFSEC requires monitoring, recording, and reporting (WAC 173-220-210 and 40 CFR 122.41) to verify that the treatment process is functioning correctly and that the discharge complies with the permits effluent limits.

If a facility uses a contract laboratory to monitor wastewater, it must ensure that the laboratory uses the methods and meets or exceeds the method detection levels required by the permit. The permit describes when facilities may use alternative methods. It also describes what to do in certain situations when the laboratory encounters matrix effects. When a facility uses an alternative method as allowed by the permit, it must report the test method, DL, and QL on the discharge monitoring report or in the required report.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 43 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 The monitoring schedule is detailed in the proposed permit under Special Condition S.2.

Specified monitoring frequencies take into account the quantity and variability of the discharge, the treatment method, past compliance, significance of pollutants, and cost of monitoring.

Monitoring of cooling tower blowdown for the 126 priority pollutants (40 CFR 423 Appendix A) contained in chemicals added for cooling tower maintenance, except chromium and zinc is required annually unless the Permittee provides engineering calculations which demonstrate that the regulated pollutants are not detectable in the final discharge by the analytical methods in 40 CFR part 136.

Previous permits did not require annual monitoring. The 1995 permit fact sheet states, The permit will not require monitoring for priority pollutants because there has been no detection of these pollutants associated with chemicals used for cooling tower maintenance. However, 40 CFR 423.13(d)(3) requires engineering calculations if monitoring is not required. Therefore the proposed permit requires either annual monitoring or submittal of engineering calculations.

A. Lab accreditation EFSEC requires that facilities must use a laboratory registered or accredited under the provisions of chapter 173-50 WAC, Accreditation of Environmental Laboratories, to prepare all monitoring data (with the exception of certain parameters). Ecology accredited the laboratory at this facility for:

Table 11 Accredited Parameters General Chemistry Parameter Name Analyte Code Method Description NELAC Code Matrix Nitrate as N 1810 EPA 300.0_2.1_1993 10053200 Drinking Water (D)

Chloride 1575 EPA 300.0_2.1_1993 10053200 Non-Potable Water (N)

Fluoride 1730 EPA 300.0_2.1_1993 10053200 N

Nitrate 1805 EPA 300.0_2.1_1993 10053200 N

Nitrite 1835 EPA 300.0_2.1_1993 10053200 N

Sulfate 2000 EPA 300.0_2.1_1993 10053200 N

Chemical Oxygen Demand (COD) 1565 EPA 410.4_2_1993 10077404 N

Turbidity 2055 SM 2130 B-01 20048219 N

Alkalinity 1505 SM 2320 B-97 20045607 N

Specific Conductance 1610 SM 2510 B-97 20048606 N

Solids, Total Dissolved 1955 SM 2540 C-97 20050402 N

Solids, Total Suspended 1960 SM 2540 D-97 20051201 N

Chromium VI 1045 SM 3500-Cr D-90 20067009 N

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 44 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Table 11 Accredited Parameters General Chemistry Parameter Name Analyte Code Method Description NELAC Code Matrix pH 1900 SM 4500-H+ B-00 20105219 N

Ammonia 1515 SM 4500-NH3 D-97 20109404 N

Orthophosphate 1870 SM 4500-P E-99 20124214 N

Phosphorus, total 1910 SM 4500-P E-99 20124214 N

Total Organic Carbon 2040 SM 5310 B-00 20137819 N

Chlorine (Residual), Total 1940 SM 4500-Cl D-00 20080108 D

Chlorine (Residual), Total 1940 SM 4500-Cl G-00 20081612 D

Chlorine (Residual), Total 1940 SM 4500-Cl D-00 20080108 N

Chlorine (Residual), Total 1940 SM 4500-Cl G-00 20081612 N

Microbiology Parameter Name Analyte Code Method Description NELAC Code Matrix Total Coli/Ecoli - detect WA6020 SM 9223 B Colilert 20212208 D

Metals Parameter Name Analyte Code Method Description NELAC Code Matrix Copper 1055 EPA 200.8_5.4_1994 10014605 D

Lead 1075 EPA 200.8_5.4_1994 10014605 D

Aluminum 1000 EPA 200.8_5.4_1994 10014605 N

Antimony 1005 EPA 200.8_5.4_1994 10014605 N

Arsenic 1010 EPA 200.8_5.4_1994 10014605 N

Barium 1015 EPA 200.8_5.4_1994 10014605 N

Beryllium 1020 EPA 200.8_5.4_1994 10014605 N

Boron 1025 EPA 200.8_5.4_1994 10014605 N

Cadmium 1030 EPA 200.8_5.4_1994 10014605 N

Calcium 1035 EPA 200.8_5.4_1994 10014605 N

Chromium 1040 EPA 200.8_5.4_1994 10014605 N

Cobalt 1050 EPA 200.8_5.4_1994 10014605 N

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 45 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Metals Parameter Name Analyte Code Method Description NELAC Code Matrix Copper 1055 EPA 200.8_5.4_1994 10014605 N

Iron 1070 EPA 200.8_5.4_1994 10014605 N

Lead 1075 EPA 200.8_5.4_1994 10014605 N

Magnesium 1085 EPA 200.8_5.4_1994 10014605 N

Manganese 1090 EPA 200.8_5.4_1994 10014605 N

Mercury 1095 EPA 200.8_5.4_1994 10014605 N

Molybdenum 1100 EPA 200.8_5.4_1994 10014605 N

Nickel 1105 EPA 200.8_5.4_1994 10014605 N

Potassium 1125 EPA 200.8_5.4_1994 10014605 N

Selenium 1140 EPA 200.8_5.4_1994 10014605 N

Silver 1150 EPA 200.8_5.4_1994 10014605 N

Sodium 1155 EPA 200.8_5.4_1994 10014605 N

Thallium 1165 EPA 200.8_5.4_1994 10014605 N

Tin 1175 EPA 200.8_5.4_1994 10014605 N

Titanium 1180 EPA 200.8_5.4_1994 10014605 N

Vanadium 1185 EPA 200.8_5.4_1994 10014605 N

Zinc 1190 EPA 200.8_5.4_1994 10014605 N

Radiochemistry Parameter Name Analyte Code Method Description NELAC Code Matrix Gross Alpha 2830 SM 7110 B 20156201 N

Gross Beta 2840 SM 7110 B 20156201 N

Cesium-134 2800 SM 7120 B 20160207 N

Cesium-137 2805 SM 7120 B 20160207 N

Gamma Emitters WA3000 SM 7120 B 20160207 N

Tritium 3030 SM 7500-3H B 20160809 N

Cesium-134 2800 SM 7120 B 20160207 Solid and Chemical Materials (S)

Cesium-137 2805 SM 7120 B 20160207 S

Gamma Emitters WA3000 SM 7120 B 20160207 S

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 46 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 B. Effluent limits which are near detection or quantitation levels The water quality-based effluent concentration limits for chromium are near the limits of current analytical methods to detect or accurately quantify. The method detection level (MDL) also known as detection level (DL) is the minimum concentration of a pollutant that a laboratory can measure and report with a 99 percent confidence that its concentration is greater than zero (as determined by a specific laboratory method). The quantitation level (QL) is the level at which a laboratory can reliably report concentrations with a specified level of error. Estimated concentrations are the values between the DL and the QL. EFSEC requires permitted facilities to report estimated concentrations. When reporting maximum daily effluent concentrations, EFSEC requires the facility to report less than X where X is the required detection level if the measured effluent concentration falls below the detection level.

V. Other Permit Conditions A. Reporting and record keeping EFSEC based Special Condition S3 on its authority to specify any appropriate reporting and record keeping requirements to prevent and control waste discharges (WAC 173-220-210).

B. Non routine and unanticipated discharges Occasionally, this facility may generate wastewater which was not characterized in the permit application because it is not a routine discharge and was not anticipated at the time of application. These wastes typically consist of waters used to pressure-test storage tanks or fire water systems or of leaks from drinking water systems.

The permit authorizes non-routine and unanticipated discharges under certain conditions.

The facility must characterize these waste waters for pollutants and examine the opportunities for reuse. Depending on the nature and extent of pollutants in this wastewater and on any opportunities for reuse, EFSEC may:

Authorize the facility to discharge the wastewater.

Require the facility to treat the wastewater.

Require the facility to reuse the wastewater.

C. Spill plan This facility stores a quantity of chemicals on-site that have the potential to cause water pollution if accidentally released. EFSEC can require a facility to develop best management plans to prevent this accidental release [Section 402(a)(1) of the Federal Water Pollution Control Act (FWPCA) and RCW 90.48.080].

Columbia Generating Station developed a plan for preventing the accidental release of pollutants to state waters and for minimizing damages if such a spill occurs. The 2006 permit referred to the plan as a Best Management Practices (BMP) Plan, while the proposed permit uses the more descriptive term of Spill Control Plan. The proposed permit requires the facility to update this plan and submit it to EFSEC.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 47 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 D. Solid waste control plan Columbia Generating Station could cause pollution of the waters of the state through inappropriate disposal of solid waste or through the release of leachate from solid waste.

This proposed permit requires this facility to update the approved solid waste control plan designed to prevent solid waste from causing pollution of waters of the state. The facility must submit the updated plan to EFSEC for approval (RCW 90.48.080). You can obtain an Ecology guidance document, which describes how to develop a Solid Waste Control Plan, at:

http://www.ecy.wa.gov/pubs/0710024.pdf E. Outfall evaluation The proposed permit requires Columbia Generating Station to conduct an outfall inspection and submit a report detailing the findings of that inspection (Special Condition S11. Outfall evaluation). The inspection must evaluate the physical condition of the discharge pipe and diffusers, and evaluate the extent of sediment accumulations in the vicinity of the outfall.

F. Operation and maintenance manual EFSEC requires industries to take all reasonable steps to properly operate and maintain their wastewater treatment system in accordance with state and federal regulations [40 CFR 122.41(e) and WAC 173-220-150 (1)(g)]. The facility will prepare and submit an operation and maintenance manual as required by state regulation for the construction of wastewater treatment facilities (WAC 173-240-150). Implementation of the procedures in the operation and maintenance manual ensures the facilitys compliance with the terms and limits in the permit.

G. Stormwater pollution prevention plan In accordance with 40 CFR 122.44(k) and 40 CFR 122.44 (s), the proposed permit includes requirements for the development and implementation of a SWPPP along with BMPs to minimize or prevent the discharge of pollutants to waters of the state. BMPs constitute Best Conventional Pollutant Control Technology (BCT) and Best Available Technology Economically Achievable (BAT) for stormwater discharges. EFSEC has determined that Columbia Generating Station must develop a SWPPP and implement adequate BMPs in order to meet the requirements of all known, available, and reasonable methods of prevention, control, and treatment (AKART). A SWPPP requires a facility to implement actions necessary to manage stormwater to comply with the states requirement under chapter 90.48 RCW to protect the beneficial uses of waters of the state.

The SWPPP must identify potential sources of stormwater contamination from industrial activities and identify how it plans to mange those sources of contamination to prevent or minimize contamination of stormwater. Columbia Generating Station must continuously review and revise the SWPPP as necessary to assure that stormwater discharges do not degrade water quality. It must retain the SWPPP on-site or within reasonable access to the site and available for review by EFSEC.

Best Management Practices (BMPs)

BMPs are the actions identified in the SWPPP to manage, prevent contamination of, and treat stormwater. BMPs include schedules of activities, prohibitions of practices, maintenance

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 48 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 procedures, and other physical, structural and/or managerial practices to prevent or reduce the pollution of waters of the state. BMPs also include treatment systems, operating procedures, and practices used to control plant site runoff, spillage or leaks, sludge or waste disposal, and drainage from raw material storage. Columbia Generating Station must ensure that its SWPPP includes the operational and structural source control BMPs listed as applicable in Ecologys stormwater management manuals. Many of these applicable BMPs are sector-specific or activity-specific, and are not required at facilities engaged in other industrial sectors or activities.

Ecology-Approved Stormwater Management Manuals Consistent with RCW 90.48.555 (5) and (6), the proposed permit requires the facility to implement BMPs contained in the Stormwater Management Manual for Eastern Washington (2004 edition), or any revisions thereof, or practices that are demonstrably equivalent to practices contained in stormwater technical manuals approved by Ecology. This should ensure that BMPs will prevent violations of state water quality standards, and satisfy the state AKART requirements and the federal technology-based treatment requirements under 40 CFR part 125.3. The SWPPP must document that the BMPs selected provide an equivalent level of pollution prevention, compared to the applicable Stormwater Management Manuals, including: The technical basis for the selection for all stormwater BMPs (scientific, technical studies, and/or modeling) which support the performance claims for the BMPs selected.

An assessment of how the BMPs will satisfy AKART requirements and the applicable technology-based treatment requirements under 40 CFR part 125.3.

Operational Source Control BMPs Operational source control BMPs include a schedule of activities, prohibition of practices, maintenance procedures, employee training, good housekeeping, and other managerial practices to prevent or reduce the pollution of waters of the state. These activities do not require construction of pollution control devices but are very important components of a successful SWPPP. Employee training, for instance, is critical to achieving timely and consistent spill response. Pollution prevention is likely to fail if the employees do not understand the importance and objectives of BMPs. Prohibitions might include eliminating outdoor repair work on equipment and certainly would include the elimination of intentional draining of crankcase oil on the ground. Good housekeeping and maintenance schedules help prevent incidents that could result in the release of pollutants. Operational BMPs represent a cost-effective way to control pollutants and protect the environment. The SWPPP must identify all the operational BMPs and how and where they are implemented. For example, the SWPPP must identify what training will consist of, when training will take place, and who is responsible to assure that employee training happens.

Structural Source Control BMPs Structural source control BMPs include physical, structural, or mechanical devices or facilities intended to prevent pollutants from entering stormwater. Examples of source control BMPs include erosion control practices, maintenance of stormwater facilities (e.g.,

cleaning out sediment traps), construction of roofs over storage and working areas, and direction of equipment wash water and similar discharges to the sanitary sewer or a dead end

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 49 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 sump. Structural source control BMPs likely include a capital investment but are cost effective compared to cleaning up pollutants after they have entered stormwater.

Treatment BMPs Operational and structural source control BMPs are designed to prevent pollutants from entering stormwater. However, even with an aggressive and successful program, stormwater may still require treatment to achieve compliance with water quality standards. Treatment BMPs remove pollutants from stormwater. Examples of treatment BMPs are detention ponds, oil/water separators, biofiltration, and constructed wetlands.

Volume/Flow Control BMPs EFSEC recognizes the need to include specific BMP requirements for stormwater runoff quantity control to protect beneficial water uses, including fish habitat. New facilities and existing facilities undergoing redevelopment must implement the requirements for peak runoff rate and volume control identified by chapter 2 in the Eastern Washington SWMM.

Chapter 6 in the Eastern Washington SWMM lists BMPs to accomplish rate and volume control. Chapter 2 (Core Elements for New Development and Redevelopment) in the Eastern Washington SWMM contains the minimum technical requirements for facilities east of the Cascades. Although not required to implement these BMPs, controlling rate and volume of stormwater discharge maintains the health of the watershed. Existing facilities should identify control measures that they can implement over time to reduce the impact of uncontrolled release of stormwater.

H. Compliance schedule The proposed permit includes a compliance schedule primarily to address the facilitys discharges to ground. It also requires relocation of the facilitys temperature monitoring location to the River Pumphouse, adjacent to the Columbia River. Discharge currently travels over three miles through a vented pipe after temperature monitoring and before reaching the River. Temperature from the new location will be more representative of the actual discharge.

The 2006 permit required Energy Northwest to complete a groundwater quality study, which was conducted between October 2007 and October 2010. Energy Northwest submitted the groundwater quality study (Energy Northwest Columbia Generation Station Groundwater Quality Study Report, May 2012) with the permit renewal application. They also proposed replacing Outfall 002 with a double-lined evaporation pond with leak detection. EFSEC considered the studys findings, Energy Northwests proposal, and past permit documentation to determine appropriate requirements to assure compliance with groundwater quality standards for Outfall 002.

The groundwater quality standards (Chapter 173-200 WAC) and permitting regulations (Chapter 173-216 WAC) require that all known, available, and reasonable methods of prevention, control, and treatment (AKART) are applied to discharges. Energy Northwest submitted an engineering report for construction of a double-lined impoundment on June 15, 2013. The compliance schedule in the proposed permit requires submittal of an Operation and Maintenance (O&M) Manual for the double-lined impoundment, and construction of the

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 50 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 impoundment. EFSEC has determined that construction and proper O&M of the double-lined impoundment constitutes AKART for discharges to Outfall 002.

The groundwater study also identified significant ground water mounding around the facilitys cooling towers, near Outfall 003. Outfall 003 has not received a discharge since 2003, indicating that the mounding is the result of an unintentional discharge. The mounding impacted the upstream monitoring wells for Outfall 003 and enforcement limits could not be determined. The proposed permit does not authorize discharge to Outfall 003 for reasons addressed further in Section II.A of this fact sheet. Because discharges are no longer authorized, continued groundwater monitoring to establish enforcement limits for Outfall 003 is unnecessary. However, continued groundwater monitoring is required to address the mounding observed in the study.

The proposed permit includes requirements for an AKART analysis of the unintentional discharge indicated by the mounding observed around the facilitys cooling towers. The analysis, documented in an engineering report prepared in accordance with Chapter 173-240 WAC, must be submitted with the permit renewal application.

In addition, the proposed permit includes a requirement to update the facilitys Ground Water Quality Study Quality Assurance Project Plan (QAPP). An initial update is required to reflect changes based on the results of studies and the plans and requirements for Outfalls 002 and 003. A second update is required to reflect the findings of the engineering report required for the mounding observed around the cooling towers.

I. General conditions EFSEC bases the standardized General Conditions on state and federal law and regulations.

They are included in all individual industrial NPDES permits issued by EFSEC.

VI. Permit Issuance Procedures A. Permit modifications EFSEC may modify this permit to impose numerical limits, if necessary to comply with water quality standards for surface waters, with sediment quality standards, or with water quality standards for groundwaters, after obtaining new information from sources such as inspections, effluent monitoring, outfall studies, and effluent mixing studies.

EFSEC may also modify this permit to comply with new or amended state or federal regulations.

B. Proposed permit Issuance This proposed permit includes all statutory requirements for EFSEC to authorize a wastewater discharge. The permit includes limits and conditions to protect human health and aquatic life, and the beneficial uses of waters of the state of Washington. EFSEC proposes to issue this permit for a term of 5 years.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 51 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 VII. REFERENCES FOR TEXT AND APPENDICES Energy Northwest 2013. Why Cylindrical Screens in Flowing Water Impinge and Entrain Few Fish and Its Importance for the Columbia Generation Stations Intake, Discussion Paper for Meeting Between Energy Northwest and National Marine Fisheries Service, November 13, 2013, November 7, 2013. (Prepared by Charles C. Coutant, Ph.D.)

2012. Energy Northwest Columbia Generation Station Groundwater Quality Study Report, May 2012. (Prepared by Freestone Environmental Services, Inc.)

2008. Energy Northwest Columbia Generation Station Effluent Mixing Study, June 2008.

1980. Preoperational Environmental Monitoring Studies Near WNP 1,2 and 4 August 1978 Through March 1980, June 1980. (Prepared by Beak Consultants Incorporated)

Environmental Protection Agency (EPA) 1992. National Toxics Rule. Federal Register, V. 57, No. 246, Tuesday, December 22, 1992.

1991. Technical Support Document for Water Quality-based Toxics Control. EPA/505/2 001.

1988. Technical Guidance on Supplementary Stream Design Conditions for Steady State Modeling. USEPA Office of Water, Washington, D.C.

1985. Water Quality Assessment: A Screening Procedure for Toxic and Conventional Pollutants in Surface and Ground Water. EPA/600/6-85/002a.

1983. Water Quality Standards Handbook. USEPA Office of Water, Washington, D.C.

National Marine Fisheries Service 2012. Letter, Columbia Generating Station - Pending Application for NPDES permit renewal, May 7, 2012.

Tsivoglou, E.C., and J.R. Wallace.

1972. Characterization of Stream Reaeration Capacity. EPA-R3-72-012. (Cited in EPA 1985 op.cit.)

United States Nuclear Regulatory Commission 2011. Letter, Response to Letter of Non-concurrence on Biological Assessment for Proposed License Renewal of Columbia Generating Station (TAC No. ME3121; NMFS Consultation No. F/NWR/2011/05286), December 20, 2011.

Washington State Department of Ecology.

December 2011. Permit Writers Manual. Publication Number 92-109 (https://fortress.wa.gov/ecy/publications/SummaryPages/92109.html)

Laws and Regulations( http://www.ecy.wa.gov/laws-rules/index.html)

Permit and Wastewater Related Information (http://www.ecy.wa.gov/programs/wq/permits/guidance.html )

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 52 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 February 2007. Focus Sheet on Solid Waste Control Plan, Developing a Solid Waste Control Plan for Industrial Wastewater Discharge Permittees, Publication Number 07-10-024. http://www.ecy.wa.gov/pubs/0710024.pdf Wright, R.M., and A.J. McDonnell.

1979. In-stream Deoxygenation Rate Prediction. Journal Environmental Engineering Division, ASCE. 105(EE2). (Cited in EPA 1985 op.cit.)

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 53 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Appendix A--Public Involvement Information EFSEC proposes to reissue a permit to Energy Northwests Columbia Generating Station. The permit includes wastewater discharge limits and other conditions. This fact sheet describes the facility and EFSECs reasons for requiring permit conditions.

EFSEC placed a Public Notice of Application on February 3, 2014 and February 10, 2014 in Tri-City Herald to inform the public about the submitted application and to invite comment on the reissuance of this permit.

EFSEC will place a Public Notice of Draft on February 3, 2014 and February 10, 2014 in Tri-City Herald to inform the public and to invite comment on the proposed draft National Pollutant Discharge Elimination System permit and fact sheet.

The notice:

Tells where copies of the draft Permit and Fact Sheet are available for public evaluation (a local public library, the closest Regional or Field Office, posted on our website).

Offers to provide the documents in an alternate format to accommodate special needs.

Urges people to submit their comments, in writing, before the end of the Comment Period Tells how to request a public hearing of comments about the proposed NPDES permit.

Explains the next step(s) in the permitting process.

STATE OF WASHINGTON ENERGY FACILITY SITE EVALUATION COUNCIL PO Box 43172 Olympia, Washington 98504-3172 PUBLIC NOTICE OF APPLICATION PUBLIC NOTICE AND PUBLIC HEARING To receive public comments for the PROPOSED NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES) PERMIT REISSUANCE For the ENERGY NORTHWEST COLUMBIA GENERATING STATION

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 54 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Application for Reissuance In accordance with the provisions of Chapter 80.50 and 90.48 of the Revised Code of Washington; Chapters 463 and 173 of the Washington Administrative Code; and the Federal Water Pollution Control Act as amended; NOTICE is hereby given that the Washington State Energy Facility Site Evaluation Council (EFSEC or Council) has received an application from Energy Northwest, P.O. Box 968, Richland, Washington, 99352-0968, for reissuance of NPDES Permit No. WA-002515-1, for the Columbia Generating Station.

NPDES Permit No. WA-002515-1 is a wastewater discharge permit for Energy Northwests Columbia Generating Station located on the U.S. Department of Energys Hanford Site. The Columbia Generating Station is a boiling water nuclear power reactor that has been in commercial operation since 1984. The plant discharges to the Columbia River at Outfall 001.

This reissuance also authorizes discharges to ground of process wastewater at Outfall 002 until the completion of Energy Northwests evaporation pond, which is anticipated to occur by July, 2014. The draft permit also removes Energy Northwests authorization to discharge process wastewater to ground from Outfall 003.

Tentative Determination to Reissue Permit A tentative determination has been made to reissue NPDES Permit No. WA-002515-1, for Energy Northwests Columbia Generating Station (formerly WNP-2) for a period of five years beginning from the date of final adoption, subject to appropriate changes or adjustments as may result from public comments, the public hearing record, or the U.S. Environmental Protection Agency (EPA) review. Pursuant to Council regulation, the tentative determination is based on a draft permit that sets forth the following: 1) proposed effluent limitations; 2) schedules of compliance; and 3) other terms and special conditions. Details about this determination are contained in a fact sheet describing the permit conditions and any changes proposed for this facility.

Public Participation The purpose of this notice is to inform the public and interested agencies that an application, fact sheet and draft permit are available for review. This notice also serves as an announcement of a public hearing to receive written and oral comments. The public hearing will be held at 1:30 p.m., Thursday, March 6, 2014.

Copies of Application, Fact Sheet and Draft Permit Available The application, draft permit and fact sheet may be viewed at the EFSEC website:

http://www.efsec.wa.gov/Columbia%20Generating%20Station/NPDES%202014.shtml.

Copies of the application, fact sheet and draft permit are on file in the Council Office, located at the Utilities and Transportation Commission, 1300 S. Evergreen Park Dr. S.W., Olympia, Washington 98504, and are available for inspection and copying by any interested member of the public. Review of the documents can be arranged by calling EFSEC at 360-664-1345. Copies will also be mailed to persons or agencies upon request.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 55 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Comments Invited The Council invites interested persons to submit written comments concerning the tentative determination to reissue the permit. Written comments should be mailed to:

Energy Facility Site Evaluation Council Attention: Jim La Spina P.O. Box 43172 Olympia, WA 98504-3172 Comments may also be submitted by email at efsec@utc.wa.gov.

The Council will consider all written comments submitted during the comment period in formulating its final determination. The Councils response to all significant comments will be available upon request. All comments must be received by EFSEC no later than 5 pm on March 14, 2014.

Public Hearing NOTICE IS HEREBY GIVEN that a hearing in this matter will be held at 1:30 p.m., Thursday, March 6, 2014, in Room 206 at the Utilities and Transportation Commission, 1300 S. Evergreen Park Dr. S.W., Olympia, Washington. The hearing will be conducted in accordance with the states Administrative Procedures Act, Chapter 34.05 Revised Code of Washington.

Council Action After the public hearing and after the close of the comment period, the Council will consider the information before it and reach a decision on reissuing the permit in such form as it considers appropriate.

Washington State Energy Facility Site Evaluation Council By

/s/

Stephen Posner Interim EFSEC Manager Dated at Olympia, Washington this 3rd day of February, 2014.

You may obtain further information from EFSEC by telephone, 360-956-2121, or by writing to the address listed below.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 56 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Energy Facility Site Evaluation Council P.O. Box 43172 Olympia, WA 98504-3172

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 57 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Appendix B--Appeals of the NPDES Permit This NPDES permit is subject to judicial review pursuant to WAC 463-76-063 and the Administrative Procedure Act, Chapter 34.05 RCW. The Administrative Procedure Act can be found on-line at http://apps.leg.wa.gov/rcw/default.aspx?cite=34.05.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 58 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Appendix C--Glossary 1-DMax or 1-day maximum temperature -- The highest water temperature reached on any given day. This measure can be obtained using calibrated maximum/minimum thermometers or continuous monitoring probes having sampling intervals of thirty minutes or less.

7-DADMax or 7-day average of the daily maximum temperatures -- The arithmetic average of seven consecutive measures of daily maximum temperatures. The 7-DADMax for any individual day is calculated by averaging that day's daily maximum temperature with the daily maximum temperatures of the three days prior and the three days after that date.

Acute toxicity --The lethal effect of a compound on an organism that occurs in a short time period, usually 48 to 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br />.

AKART -- The acronym for all known, available, and reasonable methods of prevention, control and treatment. AKART is a technology-based approach to limiting pollutants from wastewater discharges, which requires an engineering judgment and an economic judgment.

AKART must be applied to all wastes and contaminants prior to entry into waters of the state in accordance with RCW 90.48.010 and 520, WAC 173-200-030(2)(c)(ii), and WAC 173-216-110(1)(a).

Alternate point of compliance -- An alternative location in the groundwater from the point of compliance where compliance with the groundwater standards is measured. It may be established in the groundwater at locations some distance from the discharge source, up to, but not exceeding the property boundary and is determined on a site specific basis following an AKART analysis. An early warning value must be used when an alternate point is established. An alternate point of compliance must be determined and approved in accordance with WAC 173-200-060(2).

Ambient water quality -- The existing environmental condition of the water in a receiving water body.

Ammonia -- Ammonia is produced by the breakdown of nitrogenous materials in wastewater.

Ammonia is toxic to aquatic organisms, exerts an oxygen demand, and contributes to eutrophication. It also increases the amount of chlorine needed to disinfect wastewater.

Annual average design flow (AADF -- average of the daily flow volumes anticipated to occur over a calendar year.

Average monthly (intermittent) discharge limit-- The average of the measured values obtained over a calendar months time taking into account zero discharge days.

Average monthly discharge limit -- The average of the measured values obtained over a calendar month's time.

Background water quality -- The concentrations of chemical, physical, biological or radiological constituents or other characteristics in or of groundwater at a particular point in time upgradient of an activity that has not been affected by that activity, [WAC 173-200-020(3)]. Background water quality for any parameter is statistically defined as the 95% upper tolerance interval with a 95% confidence based on at least eight hydraulically upgradient water quality samples. The eight samples are collected over a period of at least one year, with no more than one sample collected during any month in a single calendar year.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 59 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Best management practices (BMPs) -- Schedules of activities, prohibitions of practices, maintenance procedures, and other physical, structural and/or managerial practices to prevent or reduce the pollution of waters of the state. BMPs include treatment systems, operating procedures, and practices to control: plant site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw material storage. BMPs may be further categorized as operational, source control, erosion and sediment control, and treatment BMPs.

BOD5 -- Determining the five-day Biochemical Oxygen Demand of an effluent is an indirect way of measuring the quantity of organic material present in an effluent that is utilized by bacteria. The BOD5 is used in modeling to measure the reduction of dissolved oxygen in receiving waters after effluent is discharged. Stress caused by reduced dissolved oxygen levels makes organisms less competitive and less able to sustain their species in the aquatic environment. Although BOD5 is not a specific compound, it is defined as a conventional pollutant under the federal Clean Water Act.

Bypass -- The intentional diversion of waste streams from any portion of a treatment facility.

Categorical pretreatment standards -- National pretreatment standards specifying quantities or concentrations of pollutants or pollutant properties, which may be discharged to a POTW by existing or new industrial users in specific industrial subcategories.

Chlorine -- A chemical used to disinfect wastewaters of pathogens harmful to human health. It is also extremely toxic to aquatic life.

Chronic toxicity -- The effect of a compound on an organism over a relatively long time, often 1/10 of an organism's lifespan or more. Chronic toxicity can measure survival, reproduction or growth rates, or other parameters to measure the toxic effects of a compound or combination of compounds.

Clean water act (CWA -- The federal Water Pollution Control Act enacted by Public Law 92-500, as amended by Public Laws95-217, 95-576,96-483, 97-117; USC 1251 et seq.

Compliance inspection-without sampling -- A site visit for the purpose of determining the compliance of a facility with the terms and conditions of its permit or with applicable statutes and regulations.

Compliance inspection-with sampling -- A site visit for the purpose of determining the compliance of a facility with the terms and conditions of its permit or with applicable statutes and regulations. In addition it includes as a minimum, sampling and analysis for all parameters with limits in the permit to ascertain compliance with those limits; and, for municipal facilities, sampling of influent to ascertain compliance with the 85 percent removal requirement. EFSEC may conduct additional sampling.

Composite sample -- A mixture of grab samples collected at the same sampling point at different times, formed either by continuous sampling or by mixing discrete samples. May be "time-composite" (collected at constant time intervals) or "flow-proportional" (collected either as a constant sample volume at time intervals proportional to stream flow, or collected by increasing the volume of each aliquot as the flow increased while maintaining a constant time interval between the aliquots).

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 60 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Construction activity -- Clearing, grading, excavation, and any other activity, which disturbs the surface of the land. Such activities may include road building; construction of residential houses, office buildings, or industrial buildings; and demolition activity.

Continuous monitoring -- Uninterrupted, unless otherwise noted in the permit.

Critical condition -- The time during which the combination of receiving water and waste discharge conditions have the highest potential for causing toxicity in the receiving water environment. This situation usually occurs when the flow within a water body is low, thus, its ability to dilute effluent is reduced.

Date of receipt - This is defined in RCW 43.21B.001(2) as five business days after the date of mailing; or the date of actual receipt, when the actual receipt date can be proven by a preponderance of the evidence. The recipient's sworn affidavit or declaration indicating the date of receipt, which is unchallenged by the agency, constitutes sufficient evidence of actual receipt. The date of actual receipt, however, may not exceed forty-five days from the date of mailing.

Detection limit -- The minimum concentration of a substance that can be measured and reported with 99 percent confidence that the pollutant concentration is above zero and is determined from analysis of a sample in a given matrix containing the pollutant.

Dilution factor (DF) -- A measure of the amount of mixing of effluent and receiving water that occurs at the boundary of the mixing zone. Expressed as the inverse of the percent effluent fraction, for example, a dilution factor of 10 means the effluent comprises 10% by volume and the receiving water 90%.

Distribution uniformity -- The uniformity of infiltration (or application in the case of sprinkle or trickle irrigation) throughout the field expressed as a percent relating to the average depth infiltrated in the lowest one-quarter of the area to the average depth of water infiltrated.

Early warning value -- The concentration of a pollutant set in accordance with WAC 173-200-070 that is a percentage of an enforcement limit. It may be established in the effluent, groundwater, surface water, the vadose zone or within the treatment process. This value acts as a trigger to detect and respond to increasing contaminant concentrations prior to the degradation of a beneficial use.

Enforcement limit -- The concentration assigned to a contaminant in the groundwater at the point of compliance for the purpose of regulation, [WAC 173-200-020(11)]. This limit assures that a groundwater criterion will not be exceeded and that background water quality will be protected.

Engineering report -- A document that thoroughly examines the engineering and administrative aspects of a particular domestic or industrial wastewater facility. The report must contain the appropriate information required in WAC 173-240-060 or 173-240-130.

Fecal coliform bacteria -- Fecal coliform bacteria are used as indicators of pathogenic bacteria in the effluent that are harmful to humans. Pathogenic bacteria in wastewater discharges are controlled by disinfecting the wastewater. The presence of high numbers of fecal coliform bacteria in a water body can indicate the recent release of untreated wastewater and/or the presence of animal feces.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 61 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Grab sample -- A single sample or measurement taken at a specific time or over as short a period of time as is feasible.

Groundwater -- Water in a saturated zone or stratum beneath the surface of land or below a surface water body.

Industrial user -- A discharger of wastewater to the sanitary sewer that is not sanitary wastewater or is not equivalent to sanitary wastewater in character.

Industrial wastewater -- Water or liquid-carried waste from industrial or commercial processes, as distinct from domestic wastewater. These wastes may result from any process or activity of industry, manufacture, trade or business; from the development of any natural resource; or from animal operations such as feed lots, poultry houses, or dairies. The term includes contaminated storm water and, also, leachate from solid waste facilities.

Interference -- A discharge which, alone or in conjunction with a discharge or discharges from other sources, both:

• Inhibits or disrupts the POTW, its treatment processes or operations, or its sludge processes, use or disposal; and

• Therefore is a cause of a violation of any requirement of the POTW's NPDES permit (including an increase in the magnitude or duration of a violation) or of the prevention of sewage sludge use or disposal in compliance with the following statutory provisions and regulations or permits issued thereunder (or more stringent State or local regulations):

Section 405 of the Clean Water Act, the Solid Waste Disposal Act (SWDA) (including title II, more commonly referred to as the Resource Conservation and Recovery Act (RCRA), and including State regulations contained in any State sludge management plan prepared pursuant to subtitle D of the SWDA), sludge regulations appearing in 40 CFR Part 507, the Clean Air Act, the Toxic Substances Control Act, and the Marine Protection, Research and Sanctuaries Act.

Local limits -- Specific prohibitions or limits on pollutants or pollutant parameters developed by a POTW.

Major facility -- A facility discharging to surface water with an EPA rating score of > 80 points based on such factors as flow volume, toxic pollutant potential, and public health impact.

Maximum daily discharge limit -- The highest allowable daily discharge of a pollutant measured during a calendar day or any 24-hour period that reasonably represents the calendar day for purposes of sampling. The daily discharge is calculated as the average measurement of the pollutant over the day.

Maximum day design flow (MDDF) -- The largest volume of flow anticipated to occur during a one-day period, expressed as a daily average.

Maximum month design flow (MMDF) -- The largest volume of flow anticipated to occur during a continuous 30-day period, expressed as a daily average.

Maximum week design flow (MWDF) -- The largest volume of flow anticipated to occur during a continuous 7-day period, expressed as a daily average.

Method detection level (MDL) -- See Method Detection Level.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 62 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Minor facility -- A facility discharging to surface water with an EPA rating score of < 80 points based on such factors as flow volume, toxic pollutant potential, and public health impact.

Mixing zone -- An area that surrounds an effluent discharge within which water quality criteria may be exceeded. The permit specifies the area of the authorized mixing zone that EFSEC defines following procedures outlined in state regulations (chapter 173-201A WAC).

National pollutant discharge elimination system (NPDES) -- The NPDES (Section 402 of the Clean Water Act) is the federal wastewater permitting system for discharges to navigable waters of the United States. Many states, including the state of Washington, have been delegated the authority to issue these permits. NPDES permits issued by Washington State permit writers are joint NPDES/State permits issued under both state and federal laws.

pH -- The pH of a liquid measures its acidity or alkalinity. It is the negative logarithm of the hydrogen ion concentration. A pH of 7 is defined as neutral and large variations above or below this value are considered harmful to most aquatic life.

Pass-through -- A discharge which exits the POTW into waters of the State in quantities or concentrations which, alone or in conjunction with a discharge or discharges from other sources, is a cause of a violation of any requirement of the POTW's NPDES permit (including an increase in the magnitude or duration of a violation), or which is a cause of a violation of State water quality standards.

Peak hour design flow (PHDF) -- The largest volume of flow anticipated to occur during a one-hour period, expressed as a daily or hourly average.

Peak instantaneous design flow (PIDF) -- The maximum anticipated instantaneous flow.

Point of compliance -- The location in the groundwater where the enforcement limit must not be exceeded and a facility must comply with the Ground Water Quality Standards. EFSEC determines this limit on a site-specific basis. EFSEC locates the point of compliance in the groundwater as near and directly downgradient from the pollutant source as technically, hydrogeologically, and geographically feasible, unless it approves an alternative point of compliance.

Potential significant industrial user (PSIU) --A potential significant industrial user is defined as an Industrial User that does not meet the criteria for a Significant Industrial User, but which discharges wastewater meeting one or more of the following criteria:

a. Exceeds 0.5 % of treatment plant design capacity criteria and discharges <25,000 gallons per day or;

b. Is a member of a group of similar industrial users which, taken together, have the potential to cause pass through or interference at the POTW (e.g. facilities which develop photographic film or paper, and car washes).

Ecology may determine that a discharger initially classified as a potential significant industrial user should be managed as a significant industrial user.

Quantitation level (QL) -- Also known as Minimum Level of Quantitation (ML) - The lowest level at which the entire analytical system must give a recognizable signal and acceptable calibration point for the analyte. It is equivalent to the concentration of the lowest calibration standard, assuming that the lab has used all method-specified sample weights, volumes, and

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 63 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 cleanup procedures. The QL is calculated by multiplying the MDL by 3.18 and rounding the result to the number nearest to (1,2,or 5) x 10n, where n is an integer. (64 FR 30417).

ALSO GIVEN AS:

The smallest detectable concentration of analyte greater than the Detection Limit (DL) where the accuracy (precision & bias) achieves the objectives of the intended purpose. (Report of the Federal Advisory Committee on Detection and Quantitation Approaches and Uses in Clean Water Act Programs Submitted to the US Environmental Protection Agency December 2007).

Reasonable potential -- A reasonable potential to cause a water quality violation, or loss of sensitive and/or important habitat.

Responsible corporate officer -- A president, secretary, treasurer, or vice-president of the corporation in charge of a principal business function, or any other person who performs similar policy-or decision-making functions for the corporation, or the manager of one or more manufacturing, production, or operating facilities employing more than 250 persons or have gross annual sales or expenditures exceeding $25 million (in second quarter 1980 dollars), if authority to sign documents has been assigned or delegated to the manager in accordance with corporate procedures (40 CFR 122.22).

Significant industrial user (SIU) --

1) All industrial users subject to Categorical Pretreatment Standards under 40 CFR 403.6 and 40 CFR Chapter I, Subchapter N and;

2) Any other industrial user that: discharges an average of 25,000 gallons per day or more of process wastewater to the POTW (excluding sanitary, noncontact cooling, and boiler blow-down wastewater); contributes a process wastestream that makes up 5 percent or more of the average dry weather hydraulic or organic capacity of the POTW treatment plant; or is designated as such by the Control Authority* on the basis that the industrial user has a reasonable potential for adversely affecting the POTW's operation or for violating any pretreatment standard or requirement [in accordance with 40 CFR 403.8(f)(6)].

Upon finding that the industrial user meeting the criteria in paragraph 2, above, has no reasonable potential for adversely affecting the POTW's operation or for violating any pretreatment standard or requirement, the Control Authority* may at any time, on its own initiative or in response to a petition received from an industrial user or POTW, and in accordance with 40 CFR 403.8(f)(6), determine that such industrial user is not a significant industrial user.

• The term "Control Authority" refers to the Washington State Department of Ecology in the case of non-delegated POTWs or to the POTW in the case of delegated POTWs.

Slug discharge -- Any discharge of a non-routine, episodic nature, including but not limited to an accidental spill or a non-customary batch discharge to the POTW. This may include any pollutant released at a flow rate that may cause interference or pass through with the POTW or in any way violate the permit conditions or the POTWs regulations and local limits.

Soil scientist -- An individual who is registered as a Certified or Registered Professional Soil Scientist or as a Certified Professional Soil Specialist by the American Registry of Certified Professionals in Agronomy, Crops, and Soils or by the National Society of Consulting

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 64 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Scientists or who has the credentials for membership. Minimum requirements for eligibility are: possession of a baccalaureate, masters, or doctorate degree from a U.S. or Canadian institution with a minimum of 30 semester hours or 45 quarter hours professional core courses in agronomy, crops or soils, and have 5,3,or 1 years, respectively, of professional experience working in the area of agronomy, crops, or soils.

Solid waste -- All putrescible and non-putrescible solid and semisolid wastes including, but not limited to, garbage, rubbish, ashes, industrial wastes, swill, sewage sludge, demolition and construction wastes, abandoned vehicles or parts thereof, contaminated soils and contaminated dredged material, and recyclable materials.

Soluble BOD5 -- Determining the soluble fraction of Biochemical Oxygen Demand of an effluent is an indirect way of measuring the quantity of soluble organic material present in an effluent that is utilized by bacteria. Although the soluble BOD5 test is not specifically described in Standard Methods, filtering the raw sample through at least a 1.2 um filter prior to running the standard BOD5 test is sufficient to remove the particulate organic fraction.

State waters -- Lakes, rivers, ponds, streams, inland waters, underground waters, salt waters, and all other surface waters and watercourses within the jurisdiction of the state of Washington.

Stormwater--That portion of precipitation that does not naturally percolate into the ground or evaporate, but flows via overland flow, interflow, pipes, and other features of a storm water drainage system into a defined surface water body, or a constructed infiltration facility.

Technology-based effluent limit -- A permit limit based on the ability of a treatment method to reduce the pollutant.

Total coliform bacteria--A microbiological test, which detects and enumerates the total coliform group of bacteria in water samples.

Total dissolved solids--That portion of total solids in water or wastewater that passes through a specific filter.

Total maximum daily load (TMDL) --A determination of the amount of pollutant that a water body can receive and still meet water quality standards.

Total suspended solids (TSS) -- Total suspended solids is the particulate material in an effluent.

Large quantities of TSS discharged to a receiving water may result in solids accumulation.

Apart from any toxic effects attributable to substances leached out by water, suspended solids may kill fish, shellfish, and other aquatic organisms by causing abrasive injuries and by clogging the gills and respiratory passages of various aquatic fauna. Indirectly, suspended solids can screen out light and can promote and maintain the development of noxious conditions through oxygen depletion.

Upset -- An exceptional incident in which there is unintentional and temporary noncompliance with technology-based permit effluent limits because of factors beyond the reasonable control of the Permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, lack of preventative maintenance, or careless or improper operation.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 65 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Water quality-based effluent limit -- A limit imposed on the concentration of an effluent parameter to prevent the concentration of that parameter from exceeding its water quality criterion after discharge into receiving waters.

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 66 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Appendix D--Technical Calculations Several of the Excel spreadsheet tools used to evaluate a dischargers ability to meet Washington State water quality standards can be found on Ecologys webpage at:

http://www.ecy.wa.gov/programs/wq/permits/guidance.html.

Reasonable Potential Analysis: Ecologys PermitCalc Workbook determines reasonable potential (to violate the aquatic life and human health water quality standards) and calculates effluent limits. The process and formulas for determining reasonable potential and effluent limits in this Workbook are taken directly from the Technical Support Document for Water Quality-based Toxics Control, (EPA 505/2 001). The adjustment for autocorrelation is from EPA (1996a), and EPA (1996b).

Dilution Factors:

Acute Chronic Facility 9

93 Water Body Type 93 Rec. Water Hardness 93 AMMONIA, Criteria as Total NH3 CHLORINE (Total Residual) 7782505 CHROMIUM(HEX) 18540299 COPPER - 744058 6M Hardness dependent ZINC-7440666 13M hardness dependent BROMOFORM 75252 5V ANTIMONY (INORGANIC) 744036 1M ARSENIC (dissolved) 7440382 2M LEAD - 7439921 7M Dependent on hardness MERCURY 7439976 8M NICKEL - 7440020 9M -

Dependent on hardness SELENIUM 7782492 10M 22 1000 38 16 38 3

3 3

3 3

3 3

0.6 0

0.551 0.274 0.381 0.6 0.6 0.6 0.6 0.6 0.6 0.6 106 100 2.32 19.5 33.94 1.43 3.51 6.8 0.74 0.0058 3.65 1.94 13.5 37 0

1.4 0.9 2.3 0

0.1 0

0 0

0.3 0

0 0

0 0

Acute 6,766 19 15 10.681 75.286 360 37.556 2.1 931.69 20 Chronic 942 11 10 7.4404 68.748 190 1.4635 0.012 103.47 5

1300 4.3 14 0.14 610 170 Acute 0.982 0.996 0.996 1

0.466 0.85 0.998 Chronic 0.962 0.996 0.996 1

0.466 0.997 N

N N

N N

Y N

Y N

N N

N Aquatic Life Reasonable Potential 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 s

0.555 0.000 0.515 0.269 0.368 0.555 0.555 0.555 0.555 0.555 0.555 0.555 Pn 0.873 0.997 0.924 0.829 0.924 0.368 0.368 0.368 0.368 0.368 0.368 0.368 1.00 1.00 1.00 1.21 1.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 Acute 45 11.111 1.498 3.401 5.800 0.477 1.170 2.266 0.204 0.002 1.214 0.647 Chronic 38 1.075 1.409 1.142 2.639 0.046 0.113 0.219 0.110 0.000 0.117 0.063 NO NO NO NO NO n/a n/a NO NO NO NO NO 532.6 135.3 154.2 936.8 0.0 0.0 3240.0 447.3 1.8 8402.0 180.0 Human Health Reasonable Potential s

0.555 0

0.5149 0.2691 0.3682 0.5545 0.5545 0.5545 0.5545 0.5545 0.5545 0.5545 Pn 0.873 0.997 0.924 0.829 0.924 0.368 0.368 0.368 0.368 0.368 0.368 0.368 0.532 1

0.4779 0.7742 0.5898 1.2049 1.2049 1.2049 1.2049 1.2049 1.2049 1.2049 93 93 93 93 93 93 93 93 93 93 93 93 0.606 1.0753 0.0119 0.4419 0.2153 1.9E-02 4.5E-02 0.0881 0.0096 7E-05 0.0473 0.0251 n/a n/a n/a NO n/a NO NO n/a n/a NO NO NO Columiba Generating Station Freshwater 61 mg/L Aquatic Life Human Health Non-Carcinogenic Human Health Carcinogenic WQ Criteria for Protection of Human Health, ug/L Multiplier Max concentration (ug/L) at edge of Reasonable Potential? Limit Required?

Pn=(1-confidence level)1/n s2=ln(CV2+1)

Multiplier Dilution Factor Maximum Daily Limit (MDL), ug/L s2=ln(CV2+1)

Pn=(1-confidence level)1/n Effluent percentile value Reasonable Potential Calculation Effluent Data

1. of Samples (n)

Effluent Concentration, ug/L (Max. or 95th Percentile)

Pollutant, CAS No. &

NPDES Application Ref. No.

Aquatic Life Criteria, ug/L Carcinogen?

Water Quality Criteria Coeff of Variation (Cv)

Calculated 50th percentile Effluent Conc. (when n>10)

Receiving Water Data 90th Percentile Conc., ug/L Geo Mean, ug/L Metal Criteria Translator, decimal Max Conc. at edge of Chronic Zone, ug/L Reasonable Potential? Limit Required?

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 67 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014

@ Acute Boundary

@ Chronic Boundary

1. Dilution Factor at Mixing Zone Boundary 9

93

2. Ambient/Upstream/Background Conditions Temperature (deg C):

22.00 22.00 pH:

7.90 7.90 Alkalinity (mg CaCO3/L):

62.00 62.00

3. Effluent Characteristics Temperature (deg C):

34.90 34.90 pH:

8.22 8.22 Alkalinity (mg CaCO3/L):

120.00 120.00

1. Ionization Constants Upstream/Background pKa:

6.37 6.37 Effluent pKa:

6.30 6.30

2. Ionization Fractions Upstream/Background Ionization Fraction:

0.97 0.97 Effluent Ionization Fraction:

0.99 0.99

3. Total Inorganic Carbon Upstream/Background Total Inorganic Carbon (mg CaCO3/L):

64 64 Effluent Total Inorganic Carbon (mg CaCO3/L):

121 121

4. Condtions at Mixing Zone Boundary Temperature (deg C):

23.43 22.14 Alkalinity (mg CaCO3/L):

68.44 62.62 Total Inorganic Carbon (mg CaCO3/L):

70.23 64.44 pKa:

6.36 6.37 pH at Mixing Zone Boundary:

7.94 7.90 INPUT OUTPUT RESULTS p

p g

(

Supplementary Stream Design Conditions for Steady State Modeling. USEPA Office of Water, Washington D.C.)

Calculation of pH of a Mixture of Two Flows

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 68 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Core Summer Critera INPUT July 1-Sept 14

1. Chronic Dilution Factor at Mixing Zone Boundary 93.0

2. 7DADMax Ambient Temperature (T) (Upstream Background 90th percentile) 22.0 °C

3. 7DADMax Effluent Temperature (95th percentile) 34.9 °C

4. Aquatic Life Temperature WQ Criterion in Fresh Water 20.0 °C OUTPUT

5. Temperature at Chronic Mixing Zone Boundary:

22.1 °C

6. Incremental Temperature Increase or decrease:

0.1 °C

7. Maximum Allowable Incremental Temperature Increase:

0.3 °C

8. Maximum Allowable Temperature at Mixing Zone Boundary:

22.3 °C A. If ambient temp is warmer than WQ criterion

9. Does temp fall within this warmer temp range?

YES

10. Temperature Limit if Required:

NO LIMIT B. If ambient temp is cooler than WQ criterion but within 28/(Tamb+7) and within 0.3 °C of the criterion

11. Does temp fall within this incremental temp. range?

12. Temp increase allowed at mixing zone boundary, if required:

C. If ambient temp is cooler than (WQ criterion-0.3) but within 28/(Tamb+7) of the criterion

13. Does temp fall within this Incremental temp. range?

14. Temp increase allowed at mixing zone boundary, if required:

D. If ambient temp is cooler than (WQ criterion - 28/(Tamb+7))

15. Does temp fall within this Incremental temp. range?

16. Temp increase allowed at mixing zone boundary, if required:

RESULTS

17. Do any of the above cells show a temp increase?

NO

18. Temperature Limit if Required?

NO LIMIT Freshwater Temperature Reasonable Potential and Limit Calculation Based on WAC 173-201A-200(1)(c)(i)--(ii) and the Water Quality Program Guidance. All data inputs must meet WQ guidelines. The Water Quality temperature guidance document may be found at:

https://fortress.wa.gov/ecy/publications/summarypages/0610100.html

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 69 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 Instantaneous Lethality to Passing Fish Analysis:

EFSEC evaluated the potential for instantaneous lethality to passing fish using the following equation and data from the Energy Northwest Columbia Generating Station Effluent Mixing Study, June 2008 which study used the CORMIX Hydrodynamic Mixing Zone Model (CORMIX1 - Version 5.0):

T2sec = Tambient90 + (Teffluent99 - Tambient90) / (DF@2seconds).

Where:

T2sec = plume temperature 2-seconds after discharge.

Tambient90 = 90th percentile of annual maximum 1DMax background temperatures.

Teffluent99 = 99th percentile of maximum 1DMax effluent temperatures.

DF@2seconds = centerline dilution factor at 2 seconds plume travel during a 7Q10 period.

EFSEC reviewed the CORMIX1 Prediction File used to determine dilution factors for the proposed permit to determine a value for DF@2seconds. The file predicts the end of the near-field region at 1.25 seconds with a corresponding centerline dilution factor of 3.7. This value was substituted for the DF@2seconds value as follows:

T2sec = 22 + (37.9 - 22) / (3.7).

T2sec = 10.2

Fact Sheet for NPDES Permit WA002515-1Columbia Generating Station Page 70 of 70 DRAFT

[Comments]

Working Draft Date: 1/15/2014 BPJ Determination of Technology-Based Effluent Limits for Chromium and Zinc:

Appendix E--Response to Comments

[EFSEC will complete this section after the public notice of draft period.]

Dilution Factors:

Acute Chronic Facility 1

1 Water Body Type 1

Rec. Water Hardness 1

CHROMIUM(HEX) 18540299 ZINC-7440666 13M hardness dependent Effluent Data 0.551 0.381 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 1.4 2.3 0

0 0

0 0

0 Acute 15 75.286

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A Chronic 10 68.748

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A Acute 0.982 0.996

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A Chronic 0.962 0.996

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A N

N

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A Aquatic Life Limit Calculation 4

4 0.551 0.381 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Acute 15 75.286

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A Chronic 10 68.748

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A Acute 5.1703 34.217

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A Chronic 5.5292 45.11

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A 5.1703 34.217

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A 0.98 1.00

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A 8.2 53.3

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A 16.4 107.0

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A Human Health Limit Calculation 1

1

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A 1

0 0

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. DIV/0! #DIV/0!

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A

1. N/A Comments/Notes:

References:

WAC 173-201A, Technical Support Document for Water Quality-based Toxics Control, US EPA, March 1991, EPA/505/2-90-001, pages 56/99 Dilution Factor Maximum Daily Effluent Limit, ug/L Average Monthly Effluent Limit, ug/L

1. of Compliance Samples Expected per month Maximum Daily Limit (MDL), ug/L Average Monthly Limit (AML), ug/L Metal Translator or 1?

Limiting LTA, ug/L Long Term Averages, ug/L Waste Load Allocations, ug/L Permit Limit Coeff. Var. (CV), decimal LTA Coeff. Var. (CV), decimal

1. of Compliance Samples Expected per month Carcinogen?

Water Quality Criteria Aquatic Life Criteria, ug/L WQ Criteria for Protection of Human Health, ug/L Metal Criteria Translator, decimal Receiving Water Data 90th Percentile Conc., ug/L Geo Mean, ug/L Coeff of Variation (Cv)

Pollutant, CAS No. &

NPDES Application Ref. No.

Aquatic Life and Human Health Limits Calculations 61 mg/L Human Health Non-Carcinogenic Freshwater Human Health Carcinogenic Columiba Generating Station Aquatic Life