S OUTHERN ENVIRONMENTAL LAW CENTER

Transcription

1 S OUTHERN ENVIRONMENTAL LAW CENTER Telephone DEMONBREUN STREET, SUITE 205 NASHVILLE, TN Facsimile Steve Goins, Director Jamie Woods, Environmental Specialist Division of Remediation Tennessee Department of Environment and Conservation William R. Snodgrass TN Tower 312 Rosa L. Parks Ave., 14th Floor Nashville, TN Via to and Re: Inadequacy of TVA Allen Fossil Plant Remedial Investigation Work Plan Proposal re: Allen Combined Cycle Production Wells Dear Mr. Goins and Mr. Woods: We are writing to express our concern regarding the Tennessee Valley Authority (TVA) s proposal to begin operating its groundwater production wells at the Allen Combined Cycle Plant without complying with the terms of the remedial investigation (RI) required by Tennessee Department of Environment and Conservation (TDEC). We are particularly concerned that TVA s work plan does not comply with the terms of the RI intended to ensure that TVA s use of the production wells does not contaminate the City of Memphis s drinking water source, the Memphis Sand Aquifer. TDEC requested the RI after discovering extremely high levels of arsenic and lead in new groundwater monitoring wells at the East Pond, an active coal ash impoundment at the Allen Fossil Plant. After calls to revoke TVA s production well permits from concerned citizens and political leaders, including State Senator Lee Harris, TDEC announced that it had obtained TVA s agreement not to use the production wells without TDEC s permission prior to the conclusion of the RI. 1 Nevertheless, the RI work plan TVA submitted to TDEC on September 15, appears to contemplate operating the wells after performing only a perfunctory investigation that does not answer the crucial question of whether operating the production wells 1 Tom Charlier, TVA will limit use of cooling wells, pending probe, Memphis Commercial Appeal (August 24, 2017), 2 Stantec, on behalf of TVA, TVA Allen Fossil Plant Remedial Investigation Work Plan (September 15, 2017) ( RI Work Plan ). Charlottesville Chapel Hill Atlanta Asheville Birmingham Charleston Nashville Richmond Washington, DC

2 SELC Comments on Allen Remedial Investigation Work Plan Appendix E Page 2 may pull arsenic and other contaminants from the ash pond groundwater into the Memphis Sand Aquifer. 3 One of the required elements of the RI is Completion of a three-dimensional groundwater flow and transport model for the Site to evaluate groundwater flow and contamination migration in the Fluvial Aquifer under current conditions, as well as future conditions that may develop as a result of pumping from the Memphis Sand Aquifer. 4 TDEC stated that it was expediting review of the work plan for the RI in order to facilitate completion of the field investigation, so that Site characterization, and specifically aquifer characterization, is completed prior to the start-up and operation of the Memphis Sand Aquifer production wells. 5 To satisfy the three-dimensional groundwater flow and transport model requirement of the RI, TVA retained the United States Geological Survey (USGS) and the University of Memphis Center for Applied Earth Science and Engineering Research (UM). As explained in the attached technical comments provided by Global Environmental LLC, neither USGS nor UM believe that the three-dimensional model required by TDEC can be completed prior to TVA s scheduled start-up of the production wells in December Rather than delaying operation of the production wells, however, USGS and UM appear to contemplate TVA operating the production wells after running a single 24-hour pump test. 7 The 24-hour pump test proposed by USGS and UM on behalf of TVA will provide only a limited snapshot of the complex hydrogeology at the Allen Fossil Plant and Combined Cycle Plant sites, and will not reflect important factors such the influence of the rise and fall of the Mississippi River and the cumulative effect of days, months, and years of sustained aquifer drawdown by the production wells. 8 It is unacceptable to simply monitor the groundwater for future evidence of contamination, as TVA, USGS, and UM appear to be proposing to do, 9 because the monitoring will detect the contamination only after it has already caused the damage TDEC seeks to prevent by requiring the RI. TVA s proposal in the RI work plan is contrary to the plain terms of the RI as defined by TDEC, and appears to be contrary to TVA s purported agreement not to operate the wells until TDEC has determined it is safe to do so. For all of these reasons, the RI work plan undermines any assurance that TVA plans to prioritize the health of Memphis residents who rely on the Memphis Sand Aquifer for drinking water over its own interest in operating the production wells. 3 See Global Environmental, LLC, Letter to Steve Goins from Mark Quarles re: Preliminary Evaluation, Remedial Investigation Work Plan, Appendix E and Addendum () (hereinafter Global Report, attached to this letter). 4 Letter from Steve Goins, TDEC Director of Remediation Division, to Winifred Nannette Brodie, P.G., TVA Remediation Specialist, Re: TVA Allen Fossil Plant (79-735), Remedial Site Investigation Request 1 (July 18, 2017). 5 Id See Global Report 2-3; see also RI Work Plan RI Work Plan Global Report RI Work Plan, 319.

3 SELC Comments on Allen Remedial Investigation Work Plan Appendix E Page 3 To fulfill its obligation to protect the public health, TDEC should not countenance TVA s attempt to circumvent the requirements of the RI. Please clarify as soon as possible whether TDEC has or will authorize TVA to implement the RI work plan as proposed, or will require TVA to conduct its investigation in a manner that ensures the protection of the City of Memphis s primary drinking water source. Sincerely, Amanda Garcia Staff Attorney Cc: Chuck Head, chuck.head@tn.gov Joseph Sanders, joseph.sanders@tn.gov

4 Steve Goins, Director Division of Remediation Tennessee Department of Environment and Conservation William R. Snodgrass TN Tower 312 Rosa L. Parks Ave., 14 th Floor Nashville, TN RE: Preliminary Evaluation Remedial Investigation Work Plan, Appendix E and Addendum TVA Allen Fossil Plant, Memphis, Tennessee Dear Mr. Goins: On behalf of the Southern Environmental Law Center, Global Environmental, LLC has performed an initial evaluation of the revised Remedial Investigation Work Plan ( Work Plan ) dated September 15, 2017 and provided by TVA to the Tennessee Department of Environment and Conservation (TDEC) pursuant to TDEC s July 18, 2017 letter to TVA. TDEC required the remedial investigation after TVA reported high concentrations of arsenic, lead, and fluoride in groundwater monitoring wells at the Allen Fossil Plant site. This letter provides my preliminary evaluation of Appendix E of the Work Plan, which describes proposed investigative activities by a collaboration of the United States Geologic Survey ( USGS ) and the University of Memphis ( UM ) Center for Applied Earth Science and Engineering Research ( Appendix E Study ). The Appendix E Study centers around planned Memphis Sand Aquifer process water withdrawal wells associated with combined cycle natural gas power plant that is being built by TVA south of the Allen Fossil Plant. In summary and in my professional opinion, the USGS-UM proposed investigative approach falls short of providing reasonable certainty prior to startup of the combined cycle plant that the wells that TVA drilled into the Memphis Sand Aquifer will not pull contaminated groundwater from the Allen Fossil Plant deeper into the Memphis Sand Aquifer. The 24-hour pump test proposed in Appendix E cannot be relied upon to accurately predict the conditions and risks associated with long-term operation of the Memphis Sand Aquifer water supply wells. Such a test will only demonstrate a snap shot of conditions on that day. Such a basic, one-day test cannot possibly demonstrate the very complicated hydrogeologic conditions caused by large fluctuations in shallow groundwater elevations, reversal of groundwater flow directions due to connectivity with the Mississippi River, or cones of depression that will likely be created over time with pumping. For these reasons, the pump test will not give the public assurance that the Memphis Sand Aquifer is afforded protection over the life of the combine cycle plant operation. In addition, the conceptual groundwater model that USGS-UM proposes to initially develop will not meet TDEC s requirement to develop a comprehensive three-dimensional model prior to plant startup. PO Box 58302, Nashville, Tennessee

5 BACKGROUND Groundwater contamination of the shallow alluvial aquifer occurs in wells adjacent to a coal combustion waste disposal area at the Allen Fossil Plant. For example, TVA reported concentrations of arsenic in 2016 and / or 2017 that exceeded the EPA and state drinking water criterium (10 parts per billion) in up to six (6) wells that are located near a surface impoundment called the East Ash Pond. See TDEC July 11, High arsenic concentrations in the groundwater of that area are not however, a new occurrence. TVA previously reported that concentrations of arsenic in groundwater from another nearby well (well P-6 ) have exceeded the safe drinking water standard since at least 2010 (see TVA September 28-29, 2016, page 60). As a result, TVA has known about high concentrations of arsenic in this area for at least the last 7 years. In response to the presence and concentrations of metals in the groundwater adjacent to the East Ash Pond at the Allen Fossil Plant, TDEC required in its July 18, 2017 letter than TVA complete a Remedial Investigation (RI) for the characterization of the Site to identify the source of the groundwater contamination; determine the horizontal and vertical extent of groundwater contamination; characterize the shallow fluvial / alluvial aquifer with a network of progressively deeper monitoring wells; and complete a three-dimensional groundwater flow and transport model for the Allen Plant Site under current conditions and various scenarios of groundwater withdrawal. Specifically, TDEC requires that TVA complete a three-dimensional groundwater flow and transport model for the Site to evaluate groundwater flow and contaminant migration in the Fluvial Aquifer under current conditions, as well as future conditions that may develop as a result of pumping from the Memphis Sand Aquifer. The Appendix E Study is proposed to address this last requirement. PRELIMINARY EVALUATION AND CONCLUSIONS TVA contracted with USGS-UM to assist in meeting the investigative activities required by TDEC. The USGS-UM team outlined their approach in their proposal (see Appendix E of the Stantec Work Plan) and stated the primary objectives of their study were to collect information to better define the hydrologic conditions at the site and to later refine the conceptual model of the hydrogeology of the area surrounding the combined cycle (CC) plant and to develop an improved framework for simulation of groundwater flow. The team planned to meet those objectives by evaluating the following: The short-term potential for hydraulic connections between the shallow Mississippi River Alluvial Aquifer and the deeper Memphis Sand Aquifer used locally for potable water supply. The baseline and on-going groundwater data after the combined cycle plant becomes operational. The USGS-UM team determined that the groundwater flow and solute transport model required by TDEC cannot be completed before the Allen combined cycle gas plant becomes operational in calendar year USGS-UM identified several data gaps that need to be addressed before the model required by TDEC can be satisfactorily completed. USGS-UM determined that the following data gaps exist: The recent TVA-collected geologic and hydrologic data are needed to update the current conceptual model. The current Mississippi Embayment Regional Aquifer Study (MERAS) area model does not address localized effects of pumping from the Memphis Sand Aquifer in enough detail to address PO Box 58302, Nashville, Tennessee

6 potential for interaction with shallow (water-table) aquifers or to conduct solute transport simulations at scale of interest. Limited temporal and spatial water-level data are available in the Allen Fossil Plant area. Potential pathways for contaminant transport are not well defined. Despite these data gaps, the USGS-UM team proposed an approach to refine the current conceptual model of the site by conducting an initial set of action items in order to evaluate the potential shortterm effects of groundwater withdrawal from the Memphis Sand Aquifer and to establish a network of monitoring wells for long-term monitoring after startup of the combined cycle plant and operation of the withdrawal wells. In summary and in my professional opinion, the USGS-UM proposed investigative approach falls short of providing reasonable certainty prior to startup of the combined cycle plant that the wells that TVA drilled into the Memphis Sand Aquifer will not pull contaminated groundwater from the Allen Fossil Plant deeper into the Memphis Sand Aquifer. As the USGS-UM admits, their work will only result in refinement of a conceptual model. Even with completion of the proposed USGS-UM approach, significant unknowns and risks will remain undefined prior to startup of the combined cycle plant. Consider these conclusions: The USGS-UM team did not conclude if the proposed remedial investigation by Stantec on behalf of TVA will fill all of the data gaps that it identified to provide enough detail to develop a meaningful three-dimensional groundwater flow and transport model. The USGS-UM proposal simply attempts to refine an existing conceptual model based upon a very limited amount of data that will not even be collected and reported prior to plant startup. The conceptual groundwater model that USGS-UM will initially develop will not meet TDEC s requirement to develop a comprehensive three-dimensional model prior to plant startup. The proposed 24-hour pump test cannot be relied upon to accurately predict the conditions and risks associated with long-term operation of the Memphis Sand Aquifer water supply wells. As such, the usefulness of the short-term test will be limited. Such a test will only demonstrate a snap shot of conditions on that day. Such a basic, one-day test cannot possibly demonstrate, as examples, the very complicated hydrogeologic conditions caused by large fluctuations in shallow groundwater elevations; reversal of groundwater flow directions due to connectivity with the Mississippi River; or cones of depression that will likely be created over time with pumping. The USGS-UM reliance instead on groundwater monitoring wells long-term after plant startup to determine if contaminants are reaching the Memphis Sand Aquifer is a risky approach because contamination migration can occur at any time in the future. Sampling will only indicate unintended migration after it has already occurred and with potential dire consequences. I appreciate the opportunity to provide this preliminary evaluation of the Remedial Investigation Work Plan and the proposed USGS-UM team approach. If you have any questions, please contact me at or markquarles@comcast.net. Sincerely, Mark Quarles, P.G. Principal Scientist PO Box 58302, Nashville, Tennessee