Tier II Sampling and Analysis Plan, Site 12 Long-Term Monitoring

CH2MHill

This Sampling and Analysis Plan (SAP) presents the rationale and technical approach for long-term monitoring (LTM) at Site 12, Barracks Road Landfill, at Naval Weapons Station (WPNSTA) Yorktown, Yorktown, Virginia. This investigation is being conducted for the Naval Facilities Engineering Command Mid-Atlantic, under the Comprehensive Long-term Environmental Action – Navy Program, in accordance with the CERCLA Act of 1980, as amended by the Superfund Amendments and Reauthorization Act of 1986, and, to the extent practicable, the National Oil and Hazardous Substances Contingency Plan. This SAP has been completed in accordance with the Navy’s Uniform Federal Policy (UFP)-SAP guidance to ensure that environmental data collected are scientifically sound, of known and documented quality, and suitable for the intended purposes. The objectives and technical approach included in this SAP were jointly scoped by the Yorktown Tier I Partnering Team, which includes representatives from the Navy, United States Environmental Protection Agency (USEPA) Region 3, and Virginia Department of Environmental Quality. As required by the Final Site 12 Record of Decision and clarified in the Explanation of Significant Difference. LTM will be performed to confirm that the Area A cover remains protective of human health and the environment, and that downgradient areas are not adversely impacted by potential future releases from this area. Therefore, the primary objective of the long-term groundwater sampling program outlined in this SAP is to monitor the quality of the groundwater at Site 12, specifically Area A, to determine if concentrations of chemical constituents increase downgradient of the landfill from their current, acceptable levels to levels that indicate a release that might adversely impact human health and the environment may have occurred. This objective will be attained through collection of groundwater samples from eight monitoring wells (including one newly installed monitoring well) for analysis of select metals comprising of RCRA Act 8 metals (arsenic, barium, cadmium, chromium, lead, mercury, selenium, and silver) plus antimony and manganese. Samples will also be analyzed for 1,3,5-trinitrobenzene and 2,3,7,8-tetrachlorodibenzo-para-dioxin These analytes have been selected for monitoring based on ROD identified constituents of concern (1,3,5-trinitrobenzene, antimony, cadmium, manganese, and lead), additional RCRA 8 metals (arsenic, barium, chromium, mercury, selenium, and silver) that are not identified as ROD COCs but were recommended for monitoring in the previous LTM report, and a potential data gap for dioxins (2,3,7,8-TCDD) that have not previously been evaluated at the site. Downgradient analytical data will be compared to WPNSTA background upper tolerance limits and upgradient data to determine whether a release from the landfill has occurred. If it is determined that a release has occurred, results will be compared to human health and ecological screening values (ESVs) to determine if there are potentially unacceptable risks to human health or the environment. Because 2,3,7,8-TCDD, arsenic, barium, chromium, mercury, selenium, and silver are not ROD-identified COCs, they will be evaluated during the first round of LTM sampling and if they are not detected or are detected at levels that do not pose a potential unacceptable risk to human health or ecological receptors, future monitoring of these constituents will not be necessary to ensure protectiveness of the remedy and they will be removed from future rounds of LTM sampling. This SAP contains the required elements outlined in the Navy’s UFP-SAP Tier II guidance. Tables are embedded within the document and figures are provided following the text. The laboratory information cited in this SAP is specific to CHEMTECH Consulting Group of Mountainside, New Jersey, and ALS Environmental of Houston, Texas.

Tier II Sampling and Analysis Plan, Site 12 Long-Term Monitoring

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