ML20112F345

Cimarron Environmental Response Trust - 2019 Groundwater Data Evaluation Update

ML20112F345
Person / Time
Site:	07000925
Issue date:	06/28/2019
From:	Lux J Environmental Properties Management
To:	Davis P, Robert Evans, Kenneth Kalman Document Control Desk, Office of Nuclear Material Safety and Safeguards, State of OK, Dept of Environmental Quality (DEQ)
References
Download: ML20112F345 (3)

Text

9400 Ward Parkway

• Kansas City, MO 64114 Tel: 405-642-5152

• jlux@envpm.com June 28, 2019 Mr. Ken Kalman U.S. Nuclear Regulatory Commission 11555 Rockville Pike Rockville, MD 20852-2738 Mr. Paul Davis Oklahoma Department of Environmental Quality 707 North Robinson Oklahoma City, OK 73101 Mr. Robert Evans U.S. Nuclear Regulatory Commission 1600 East Lamar Blvd; Suite 400 Arlington, TX 76011-4511 Re: Docket No.70-925; License No. SNM-928 Cimarron Environmental Response Trust 2019 Groundwater Data Evaluation Update

Dear Sirs:

Solely as Trustee for the Cimarron Environmental Response Trust (CERT), Environmental Properties Management LLC (EPM) submits herein an update to the 2018 evaluation of the relationship between groundwater elevation or seasonality and contaminant concentration for groundwater at the Cimarron site.

Groundwater from Monitor Well TMW-13 was used to conduct a treatability test in 2013. The concentration of uranium in the groundwater obtained from this monitor well was consistently high, averaging approximately 4,500 picoCuries per liter (pCi/L). When groundwater from the same monitor well was used to conduct a second round of treatability tests in 2015, the concentration of uranium in the groundwater obtained from this monitor well was significantly lower, averaging approximately 630 pCi/L.

This triggered the evaluation of historical uranium concentration data, and it was discovered that concentrations at some locations varied significantly between groundwater sampling events collected in 2013 and 2015. Therefore, an evaluation of groundwater data collected from 2002 through 2016 was performed to determine if the variability in uranium concentration was an artifact of seasonal variation or groundwater levels (i.e., saturated thickness). A potential relationship between uranium and/or nitrate concentrations, and either depth to water (DTW) or season was indicated if graphs of the data showed some degree of correlation between concentration or DTW or season.

Mr. Ken Kalman U.S. Nuclear Regulatory Commission June 28, 2019 Page 2 The 2016 Groundwater Evaluation1 report was submitted to the US Nuclear Regulatory Commission (NRC) and the Oklahoma Department of Environmental Quality (DEQ) on March 6, 2017. The report concluded that there is no indication of a relationship between contaminant concentration and depth to water (DTW) or between seasonality and contaminant concentration exists, except for a potential relationship between uranium and nitrate-nitrite concentrations and DTW at Monitor Well 1393 and uranium concentrations and DTW at Monitor Well T-91.

In 2018, the evaluation was updated to include groundwater data from 2017 quarterly sampling events. The 2018 Groundwater Data Evaluation2 report was submitted to the NRC and the DEQ on March 28, 2018. This report concluded that there is no discernable relationship between contaminant concentration and DTW, or between seasonality and contaminant concentration, with the exception of a potential relationship between uranium and DTW at Monitor Wells 1385, 1393, T-91, and T-100.

The enclosed evaluation includes data from quarterly groundwater monitoring data for the same 45 locations from 2018 quarterly sampling events. It also concludes that there is no discernable relationship between contaminant concentration and DTW, with the exception of a potential relationship between uranium and DTW at Monitor Wells T-91, T-100, 1393, and TMW-13 any relationship is, at best, speculative.

EPM has discontinued the collection and analysis of groundwater samples from these 45 locations for this type of groundwater evaluation. Based on the evidence presented above, there is at best a speculative potential correlation for only one contaminant at only four of the 45 locations sampled. Therefore, the expenditure of funds to continue this sampling and evaluation process is unwarranted.

If there were a consistent correlation between contaminant concentration and depth to water (or seasonal variation), the groundwater remediation plan submitted in Facility Decommissioning Plan - Rev 13 could include provisions for accommodating the anticipated fluctuations in contaminant concentration. Because there is no such consistent correlation, there is no reason to address such fluctuations in the proposed groundwater remediation plan.

1 Burns & McDonnell, March 2017 2 Burns & McDonnell, March 2018 3 Environmental Properties Management LLC, November 2018

Mr. Ken Kalman U.S. Nuclear Regulatory Commission June 28, 2019 Page 3 Please note that a hard copy of this document is being sent to the NRC PDR to be scanned and uploaded to the NRCs public document repository. Should you have any questions or desire clarification, please contact me at (405) 641-5152.

Sincerely, Jeff Lux, P.E.

Project Manager Enclosure cc:

NRC Public Document Room