RFI Work Plan Addendum

Soils: Tarrant Association (rolling).

Known: The site consisted of a bermed area with a stockpile of shot potentially containing lead and sand. Located south of Engineering on the east side of Thompkins Road, approximately 0.1 acres in size.

Previous Investigations: Site was located during field efforts. A stockpile consisting of shot potentially containing lead and sand was stabilized and disposed of with wastes from B-32.

Data Needs: Metals sweep and analytical data (metals) for surface soils.

Rationale for Analytical Program: Based on the stockpile of shot potentially containing lead at the site, chemicals of potential concern include metals. Metals (arsenic, barium, cadmium, chromium, copper, lead, mercury, nickel and zinc) are included due to the metallic nature of the waste. Explosives, VOCs, and SVOCs are not included at this site since no evidence of waste disposal or burning has been found.

Closure Activities: The following activities constitute an initial investigation of the area of concern 46. This work will be completed as part of the requirements under the RCRA 3008(h) Order, but it is not currently included in any delivery orders.

Six grab surface soil samples will be collected. The samples will be collected around and within the area where the waste was stockpiled. Each sample will be collected between 0 and 0.5 feet. Each sample will be analyzed for metals. QA/QC samples will be collected as described in Section 2.4 of the FSP.

If elevated metals levels are detected in surface soil samples, shallow soil borings will be drilled and sampled to define the vertical extent of contamination.

Water is not expected to be encountered in the borings at the site. However, if water is discovered in any of the soil borings, those borings will be sampled and may be completed as groundwater monitoring wells as detailed in Section 2.4.1 of the Work Plan Overview. Groundwater will be sampled, where present, and each sample will be analyzed for metals. QA/QC samples will be collected as described in Section 2.4 of the FSP.

IDW will be handled as specified in the FSP.

If the results of the above work indicate that the site can be closed under RRS1 without any further investigation and/or remediation, a technical/closure report will be prepared and submitted in accordance with TNRCC closure requirements. If the site does not meet RRS1 requirements, a technical report describing the results of the investigation and recommended additional investigation and/or remediation will be prepared.