ML20212P010
| ML20212P010 | |
| Person / Time | |
|---|---|
| Issue date: | 01/01/1987 |
| From: | Matt Young NRC |
| To: | Martin D NRC |
| References | |
| REF-WM-58 NUDOCS 8703130246 | |
| Download: ML20212P010 (6) | |
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WM-58/MY/12/16/867 UE,
NOTE T0: Dan E. Martin, Section Leader dranium Recovery Projects Section FROM:
Michael Young, Hydrogeologist Uranium Reccvery Projects Sectiun
SUBJECT:
SHIPROCK, NEW MEXICO SITE TRIP REPORT On Thursday, December 11, 1986, I visited the Shiprock, NM UMTRA Project Site and attended a meeting to discuss ground-water contamination issues. 00E, TAC and Navajo Nation representatives were also present. NRC staff and Navajo representatives have, in the past, expressed concern that ground-water cuality was not adequately characterized in the vicinity of Shiprock. Thus, discussing ground-water contamination issues in light of the Shiprock Surveillance and Maintenance Plan (SMP) was the prinary purpose of this trip.
On Friday, December 17, 1986, I also attended a meeting on the special infiltration study initiated by the TAC. This meeting was organized to brief NRC and Colorado Geological Survey staff on the progress of this study and to discuss ways in which the results could be more useful to the UMTRA Program.
Enclosed is a copy of my trip report for Shiprock and the meeting on the infiltration study. A roll of slide film was taken during the visit to Shiprock and is now being processed.
I will be happy to discuss further the results of this visit at your convenience.
%S%y Michael Young, Hydrogeologist Uranium Recovery Projects Section
Enclosure:
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SHIPROCK TRIP RPT/MY/WM-58 1-I.
SUBJECT:
UMTRAP Site Visit and Tecinical Meeting DATE:
December 11, 19E6 LOCATIONS:
Shiprock, NM PARTICIPANTS:
NRC TAC DOE NAVAJO NATION BIA M. Young J. Brinkman D. Leske Masud Zaman Jim Analla P. Longmire Stanley Pollock D. Miller Tommy K. Begay, Jr.
Carol Boughton Perry Chanley PURPOSE:
wells in the vicinity of the tailings pile; 2) ground-water sampling of
- 1) Discuss the latest laboratory results from resolve concerns of inadequate characterization of ground-water quality; and 3) discuss where additional monitoring could be performed to fully characterize the site.
A.
INITIAL MEETING The initial technical meeting was scheduled to discuss the results of recent ground-wate'r analyses, performed to address concerns that ground-water quality was inadequately characterized. NRC staff members and Navajo representatives have commented that the northern end of the floodplain area, south of the San Juan River, is likely contaminated.
Further, areas in the alluvial terrace and floodplain area north of the San Juan River, may or may not be contaminated, but since these areas have not been fully characterized, this possibility can not be addressed.
The laboratory results discussed during the meeting were consistent with past results. The central area of the floodplain is highly contaminated with nitrate, sulfate and total dissolved solids. The contaminant levels appear to decrease in all directions away from the central area, where a raffinate pond was previously located. However, swampy conditions on the
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- SHIPROCV, TRIP RPT/MY/WM-58 northwestern edge of the floodplain has prevented any ground-water nonitoring. Therefore, determining the leading edge of the contaminant plume has not been possible.
The TAC representatives, recognizing that these gaps of information will further delay the SMP dccument, were receptive to suggestions of
. additional trenitoring locations.
In summary, these locations and purposes include the floodplain area northwest of the tailings pile to characterize the extent of downgradient contamination; the extreme eastern edge of the floodplain to characterize upgradient contamination; surface water samples from the San Juan River to assess potential impacts of seepage on surface-water quality; and possible locations west and south of Bob Lee Wash to characteri7e probable contamination caused by leakage from the raffinate pond.
Although a timetable for this additional monitoring work was not finalized, the TAC representatives mentioned that expediency was desired.
It was also generally agreed that publishing a final SMP, contingent upon resolution of ground-water concerns, would not really serve a purpose.
Therefore, it appears that the publishing date for the SMP may be pushed back.
B.
SITE VISIT Dave Miller (TAC /D0E) conducted the on-site tour because of his familiarity of the site and monitoring locations. During the tcur, the staff observed the following aspects of the site with respect to ground-water monitoring:
The northern area of the floodplain is very swampy, vegetated, and separated by a five-foot wide canal that traverses the floodplain.
Moving a drilling rig into this area will be very difficult.
In view of this, the TAC will try wellpoint installation.
Bob Lee Wash is continuously recharged from an open artesian well located west of the wash. The discharge rate, according to Mr.
Zaman, is greater than 200 gallons per minute.
I mentioned that closing this well may greatly facilitate natural clean-up; removing this recharge source may result in depletion of the ground-water mound on the floodplain and increase natural restoration rates. Mr.
Zaman replied that he will try to close the well.
s SHIPROCK TRIP RPT/MY/WM-58 The extreme eastern edge of the floodplain was unmonitored and appeared dry enough for movement of drilling equipment. Mr. Zaman and I both mentioned that monitoring this area (east of wells 608 and 609) should provide more representative background water quality data.
Two monitoring wells were recently drilled en the terrace area just north of the tailings pile. The owner of these wells was unclear because well completion differs with the TAC's standard procedure (i.e., no steel surface casing). Mr. Miller stated that the TAC would try to determine the owner, and the possibility of irodifying the well completion specifications so that the well can be employed in a future monitoring progran.
We looked at the infiltration gallery and discussed the possibility of cross-river contamination north of the San Juan River. Recent water quality results from ground water north of the river indicate that levels of sulfate and TDS in domestic wells decrease in an easterly direction away from the gallery. This may be due simply to residual ground-water trapped in sediments during fluvial deposition and thus unrelated to the tailings. Additional monitoring should address this uncertainty.
Several surface-water sampling points were generally agreed upon.
Each location will contain two points, one south and one north of the San Juan River. Results will be used to determine the degree of seepage water mixing in the San Juan River.
The overall purpose of the trip was fulfilled. Uncharacterized areas will be monitored to determine the extent of contamination caused by the tailings. Furthermore, future monitoring should substantiate recent conclusions that ground water north of the San Juan River is unaffected by the tailings. The TAC and DOE representatives agreed that ground-water monitoring is necessary at Shiprock and that the revised SMP will reflect this agreement. The-issue of using institutional control or ground-water restoration to protect future ground-water users was not resolved due to lack of information on natural clean-up rates. Mr. Zaman remarked that institutional control may not be an acceptable measure for ensuring public health because of the potential need of this water for his people.
It was unclear how this issue could be resolved but everyone at the meeting agreed that results from future monitoring should be factored into the decision-making.
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SHIPROCK TRIP RPT/MY/WM-58.
II.
SUBJECT:
Technical Meeting on Special Infiltration Study DATE:
December 1E, 1986 LOCATION: Albuquerque, NM PARTICIPANTS:
NRC TAC State of Colorado M. Young J. Brinkman W. Wright B. Deutsch B. Keshian G. Rice Joanne Hilton Susan Colarullo PURPOSE:
Attend technical meeting on progress and results of the TAC's infiltration study and provide input for potential improvements.
Representing NRC as the technical representative for this study, I attended an overview meeting on the objectives and progress of this study. Briefly, the objectives of the study are: 1) define extreme climatological events that may be experienced over the next 1000 years, 2) study the impacts of these events on the long-term moisture content of the radon barrier, and subsequent impacts on water flux through the tailings and radon exhalation, and 3) address the issue of exfiltration (upward movement of water) caused by evapotranspiration and capillarity. This study was initiated in mid-October and should be completed by mid-February. The TAC has contracted two researchers to review the study, provide ideas, and legitimize the results. They are: Dr. Daniel Hillel (University of Mass.) and Daniel Stevens (Daniel Stevens and Associates). DOE has asked Glendon Gee (PNL) to also provide technical support.
I Ms. Hilton presented preliminary results of the climatological portion of l
l the study. The TAC has contacted five climatological centers to request l
information on future weather patterns. Although four of the five centers agreed that the southwestern United States would be drier in the future, l
all agreed that influence from the " greenhouse effect" will overshadow past weather patterns, making any predictions subject to error.
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t SHIPROCK TRIP RPT/MY/WM-58 5-Berg Keshian discussed how his computer program, S0ILMOIST, simulated percolation through the radon barrier and tailings material. Briefly, the program incorporates hydraulic relatierships of the radon barrier, tailings material and foundation soil, and climatological data to simulate percolation rates and volumes of flux. Preliminary results, presented by Mr. Rice, indicate that intermittent rainfall events cause higher flux-rates than continuous rainfall. This is caused by the increased influence of capillary potential on ground water during intermittent rainfall.
These results are being validated against results from the TRUST model.
Mr. Keshian provided me with a draft Users Manual for S0ILMOIST.
The TAC is using the Tuba City and Gunnison UMTRA Sites as test sites for the study, which is scheduled to enc in February with a final technical meeting and presentation.
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