Area of Concern 49

RFI Work Plan Addendum

Soils: Krum complex.

Known: The site consists of one trench (4 feet x 7 feet) approximately 0.03 acres in size. No surface debris has been observed on the trench. Located southwest of deer stand 41, in the central East Pasture.

Previous Investigations: Site was located during field efforts.

Data Needs: Map, geophysical survey and analytical data (VOCs and metals) for subsurface soils.

Rationale for Analytical Program: Based on the presence of one trench with no surface debris at the site, chemicals of potential concern include VOCs and metals. Metals (arsenic, barium, cadmium, chromium, copper, lead, mercury, nickel and zinc) are included due to the possible metallic nature of the waste. VOCs analysis is included in the analytical program to detect typical contaminants associated with a disposal area. SVOCs and explosives are not included at this site since no evidence of waste burning or ammunition has been found.

Closure Activities: The following activities constitute an initial investigation of the area of concern 49. 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.

Field map AOC 49 as described in Section 2.4.1 of the Work Plan Overview.
Conduct a geophysical survey, as described in Section 2.4.1 of the Work Plan Overview, of the mapped site to identify any anomalies.
Remove any vegetation necessary to complete field activities listed below. If any potential UXO is observed during field activities, work will cease until UXO specialists are brought on site to identify and remove UXO.
Conduct a geophysical survey, as described in Section 2.4.1 of the Work Plan Overview, of the mapped site to identify any anomalies. A ground penetrating radar (GPR) device and an EM-31 instrument will be used to complete the geophysical survey. The locations of four of the corners of the survey points will be recorded using a GPS unit. Analysis of the EM data will follow field activities.
If the survey information indicates an anomaly is present, complete 3 soil borings to characterize the subsurface soils surrounding the anomaly. Two soil samples will be collected from each boring. If PID readings indicate that VOCs are present, then the subsurface soil sample from that interval will be submitted to the laboratory for analysis. If there are no PID readings throughout the total depth of the boring, samples will be collected at depths of approximately 5 and 10 feet below ground surface. The total depth of each boring will be approximately 10 feet. Each sample will be analyzed for VOCs and metals. QA/QC samples will be collected as described in Section 2.4 of the FSP.
Water is not expected to be encountered in the borings of the site. However, if water is discovered in any of the soil borings, all borings will be sampled and may be completed as groundwater monitoring wells as described in Section 2.4.1 of the Work Plan Overview. Groundwater will be sampled, where present, and each sample will be analyzed for VOCs and 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.