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HomeMy WebLinkAboutDSHW-2017-009682 - 0901a06880778ec4 DSHW-2017-009682 195 North 1950 West • Salt Lake City, UT Mailing Address: P.O. Box 144880 • Salt Lake City, UT 84114-4880 Telephone (801) 536-0200 • Fax (801) 536-0222 • T.D.D. (801) 536-4284 www.deq.utah.gov Printed on 100% recycled paper State of Utah GARY R. HERBERT Governor SPENCER J. COX Lieutenant Governor Department of Environmental Quality Alan Matheson Executive Director DIVISION OF WASTE MANAGEMENT AND RADIATION CONTROL Scott T. Anderson Director November 14, 2017 Kris Blauer, Manager Environmental Services ATK Launch Systems – Promontory P.O. Box 707 Brigham City, UT 84302-0707 RE: Screening Level Ecological Risk Assessment for Groundwater UTD009081357 Dear Mr. Blauer: The Division of Waste Management and Radiation Control has completed its review of the Screening Level Ecological Risk Assessment (SLERA) for Groundwater at the ATK, Promontory facility. Comments are enclosed. Please provide responses to the comments at your earliest convenience. If you have any questions or would like to arrange a meeting to discuss them, please call Jeff Vandel at (801) 536-0257. Sincerely, Scott T. Anderson, Director Division of Waste Management and Radiation Control STA/JV/km Enclosure: Comments on SLERA c: Lloyd Berentzen, MBA, Health Officer, Bear River Health Department Grant Koford, EHS, Environmental Health Director, Bear River Health Department Moye Lin, USEPA Region 8 Paul Hancock, ATK Launch Systems Page 1 of 5 Division of Waste Management and Radiation Control Comments Screening Level Ecological Risk Assessment for Groundwater ATK Launch Systems – Promontory Facility General Comments: 1. The document focuses on two chemicals of concern (COCs), perchlorate and trichloroethylene, without providing data summaries to support the selection of these two chemicals as COCs. Chemicals of Potential Ecological Concern (COPEC) are selected by comparing the maximum concentrations of chemicals to some media specific ecological screening levels (ESLs) Please clarify why this procedure was not followed and why the focus is only on these two chemicals. It is unknown if more COPECs should have been included without following the accepted selection process. Does the approved solute transport model predict that other COCs (e.g. 1,1 DCE or chloroform) that currently exist up-gradient will impact the springs in the future? 2. A significant amount of surface water data has been collected since the document was completed. As expected, perchlorate concentrations have increased significantly since November 2008. TCE concentrations have also increased. The potential exposure point concentrations will need to be evaluated based on current data. In addition, how do the predicted concentrations from the solute transport model match up to measured data at the springs? What are the current 30-year projected surface water concentrations for the COCs? 3. The step of comparing inorganic chemicals to background levels needs to be fully described in the report and supported by any previous review and agreement by the Division. Furthermore, the document needs to clarify why the available sediment data were not quantitatively evaluated in the SLERA. Also, please screen all the analytical data for each media sampled against screening benchmarks to show that only two COPECs need to be addressed by the SLERA. 4. Section 2.3.1 of the SLERA (bottom of Page 15) states that “the groundwater screening levels used to evaluate the method detection limits (MDLs) were taken from the human health risk assessment and although these MDLs are not based on potential ecological impacts they provided a consistent set against which to evaluate the MDL.” Please show that the analytical data DLs, when screened against media specific ecological benchmarks (Eco SL), indicate that the DLs all fall below their corresponding benchmarks. The SLERA also needs to describe how data will be reviewed to determine if they are of sufficient quantity and quality for use in risk assessment. This process should follow the protocols outlined in the EPA data quality process (EPA, 1992). 5. The SLERA qualitatively assesses inorganic chemical background levels which are not fully defined. The document indicates (see Section 2.3.1) that metal occurrences in groundwater Page 2 of 5 reflect background sources, yet neither the document nor a reference summarizes this information. High arsenic levels are excluded using this line of reasoning even though this decision is not supported by the document (see page 16). Please revise the text to describe the metals background data and how it relates to ecological risk. Specific Comments: 1. Section 2.2.7 Sensitive Species, Page 12. This section states that the American bald eagle is a federally listed threatened species. However, the document should recognize that the Interior Department removed this species from the endangered species list on June 28, 2007. The bald eagle still retains protection under the Migratory Bird Treaty Act and the Bald and Golden Eagle Protection Act (USFWS : http://www.fws.gov/midwest/eagle/). 2. Section 2.3 Data Evaluation and Contaminant Fate and Transport, Page 14. The third bullet states that the high metal levels in groundwater have been “agreed upon” as being attributable to background. The Division acknowledges that high concentrations of metals and TDS have been observed in groundwater at the site. However ATK needs to demonstrate that the high metal concentrations detected in groundwater are consistent with background concentrations. Please delete from the text the statement that high metal levels in groundwater have been agreed upon as being attributable to background. 3. Section 2.3 Data Evaluation and Contaminant Fate and Transport, Page 14. Please include in the text a discussion on metal contamination that exists in groundwater at the site (i.e., hexavalent chromium near M-508). Please discuss if hexavalent chromium contamination could be a potential ecological concern. Is it anticipated that the hexavalent chromium plume could eventually reach the springs? 4. Section 2.3.1 Off-Site Surface Water, Page 17. What are the recalibrated modeled concentrations that will be used to evaluate future exposures at the springs? 5. Section 2.3.1 Off-Site Surface Water, Page 17. Based on data collected since the Spring of 2015, it appears that Shotgun Spring is actually more contaminated than Pipe Spring (Spring 2016 TCE – Pipe Spring 6.1 J ug/L, Shotgun Spring 25.2 ug/L). Please discuss its ecological implications. 6. Section 2.3.3 Biota. Will the Bulrush concentration be adjusted to reflect current and future concentrations of perchlorate in surface water? 7. Section 2.4.1 Fat-whorled Pondsnail Risk Assessment, Pages 19 and 21. The text refers to the toxicity thresholds for perchlorate and trichloroethylene as “criteria.” This term is reserved for US EPA-derived values used as standards associated with water body designated uses. The values presented in the text should be called literature-derived toxicity thresholds which do not have the same scientific rigor as US EPA criteria. Please revise the text accordingly. 8. Section 2.4.1 Fat-whorled Pondsnail Risk Assessment, Pages 19 through 21. The text does not provide a consistent approach to the risk conclusions for each COC. The perchlorate Page 3 of 5 assessment uses future, model-derived EPCs; whereas, the TCE assessment uses current EPCs. The concluding statements on Page 21 then rely on the less conservative future estimates. Please revise the text to consistently present the toxicity threshold comparisons for the measured data, the future conservative EPCs and the future less conservative EPCs to help understand the risk potential associated with each COC. 9. Section 2.4.1 Fat-whorled Pondsnail Risk Assessment, Pages 19 through 21. Currently, the highest concentration of TCE detected in Shotgun Spring is 25.2 ug/L. This concentration was detected in the Spring of 2016. Please evaluate risk using current data and indicate what the modeled concentration for TCE will be at 30 years. 10. Section 2.5 Complete Exposure Pathways, Page 29. An exposure pathway defines the route by which a receptor is exposed to a contaminant. An example includes incidental soil ingestion by burrowing mammals or root uptake of soil contaminants by plants. The information in this section defines only the receptor groups that can be exposed but does not define the exposure pathways as suggested by the section title. The text also indicates that the information was founded on the fate and transport pathways for perchlorate, thereby excluding pathways for TCE. Please rewrite this section to identify the pathways of concern that are attributable to both perchlorate and TCE. 11. Section 2.6 Selection of Endpoints for Ecological Risk, Pages 30 through 34. This section needs to be revised to clearly describe the receptors of concern for the SLERA. The information is not consistently presented and is not carried through in a cohesive manner. For instance, the document refers to a class of potential receptors (i.e., amphibian) but does not explain if this group is important to the Facility or the SLERA process. Please begin this section with a clear, concise summary of the receptors of concern and the level to which they are to be addressed (individual, population and/or community). In addition, please discuss the surrogate target receptors chosen to represent the receptors of concern. 12. Section 2.6.1 Assessment Endpoints, Pages 30 through 32. This section presents the assessment endpoints but does not describe which surrogate receptors are used for each endpoint (i.e., the great blue heron for the “survival, health and reproduction of birds”). The text also provides toxicity profiles for perchlorate and TCE. This information should be discussed either in the ecological effects evaluation (Section 3.0) or the risk characterization (by receptor group) because it does not offer useful information to the endpoints at this stage of the SLERA. Please revise the text to describe the target receptors and confine the toxicity profiles to the appropriate sections. 13. Section 2.6.2 Measurement Endpoint, Pages 33 and 34. A concern with this Section pertains to evaluating the “fat-whorled pond snail” as the only aquatic receptor in the SLERA. It is unclear why other aquatic populations are not included or if this one species can fully describe the potential effects of the COCs to all other aquatic species. Please revise the text to better assess other aquatic groups, such as fish, invertebrates and plants. 14. Section 3.0 Screening Level Ecological Effects Evaluation, Pages 36 through 40. An effects evaluation should describe the methods for estimating ecological effects. At the SLERA level, these methods consist of dividing the EPCs (represented by the maximum concentration) by literature-derived screening benchmarks or TRVs to produce Hazard Quotients (HQs). The TRVs are chosen for each surrogate receptor and are derived from US Page 4 of 5 EPA guidance sources (such as the EcoSSLs) to represent “No Observed Adverse Effect” thresholds. “Lowest Observed Adverse Effects” thresholds are used in a baseline ecological risk assessment (BERA). This section needs to be revised to clearly describe the effects evaluation methods applied to the SLERA. 15. Section 4.0 Screening Level Exposure Estimate, Pages 40 through 45. This Section does not describe how exposure to the aquatic receptors of concern is quantified. Sections 2.6.1 and 2.6.2 identify the fat-whorled pond snail as the receptor of concern. This section needs to discuss how exposure is evaluated for this species. Please revise the text to include this information. 16. Section 4.0 Screening Level Exposure Estimate, Pages 40 through 45. The wildlife receptor dose calculations could not be verified based on the available information. Section 4.0 suggests that the calculated dose was “normalized” using the receptors’ body weights. Wildlife receptor doses are typically reported in units of mg contaminant/kg body weight per day. The text provides dose algorithms that include body weight, yet this step could not be independently verified. Furthermore, food chain modeling makes assumptions about the partition (bioaccumulation and/or bioconcentration) of COCs from abiotic matrices to food items or receptors. It appears that the SLERA uses measured concentrations to develop the plant forage tissue residues, yet this information could not be verified. The text on page 43 also indicates that the SLERA is based on an assessment of COCs that transfer to grass. The document does not state how exposure to carnivores are addressed since the approach is focused on a herbivore food chain. Finally, the text does not describe any assumptions on the partition of the COCs to food items. Please revise the text to provide (a) examples of the dose calculations, (b) the life history parameters (i.e., body weight, ingestion rate) used in dose modeling, and (c) the partition factors used to estimate COC levels in food/prey items. 17. Sections 4.3 and 4.4 Modeled Future Conditions, Page 44. Please update the wildlife drinking water and dietary dose estimates to reflect the current predicted concentrations for COCs at Shotgun and Pipe Springs. 18. Section 5.0 Screening Level Risk Calculation, Pages 46 and 47. The risk conclusions could not be independently verified due to missing information, as discussed in the comments for Section 4.0. Section 5.0 also does not summarize the risk for the aquatic receptor (the fat- whorled pond snail) and fails to integrate all of the available lines of evidence to help formulate a weight of evidence risk conclusion. Please revise the text as follows: (a) clarify the risk calculations (as previously mentioned), (b) discuss the risk conclusions for each receptor group and (c) provide a complete risk characterization based on all available lines of evidence. Furthermore, the text should be revised to remove the suggestion of calculating a cumulative Hazard Index (HI) since this approach was not used in the risk characterization. Minor Comments: 1. Section 1.0 Figure depicting the Ecological Risk Assessment process, Pages 2and 3. The figure overlaps on to Page 3. Please amend the document to contain this figure on one page. Also Figure 1-1 is missing from the document. Page 5 of 5 2. Section 1.0 Introduction, Page 3. Please revise the last sentence in the first full paragraph to clarify the statement. 3. Section 1.0 Introduction, Page 4. The last bullet (vi.) appears to be incomplete. Please revise the text to clearly state what elements of the problem formulation this component will include. 4. Section 2.3.1 Off-site Surface Water, Page 15. The text in the first full paragraph indicates that the data adequacy was evaluated using the “five criteria discussed above.” These five criteria were not discussed above and are only briefly mentioned below this statement. Please rewrite this section to clearly state how the data adequacy was addressed. This same comment applies to the text in Section 2.3.2 on Page 18. 5. Section 4.0 Screening Level Exposure Estimate, Page 40. The first sentence of this Section states “on-site COC levels are used to estimate the degree of exposure.” However, earlier information in the document suggests that the four springs occur “off-site.” Please revise the text to ensure that the terms on-site and off-site are used consistently.