RL17 Project, February 1996

Soils: No surface soils are present at the SWMU.

Known: Records indicate that the site was potentially used for disposal of miscellaneous solid waste, metal, and weapons (ES, 1993b).

Previous Investigations: During the investigation of Well 16 contamination, Parsons ES discovered that the site was used as a scrape area for soil; no surface soils were observed at the site (Parsons ES, 1995b).

SWMU B-19 was investigated as part of the study to identify the source of contaminants identified in Well 16. No anomalies were detected during the geophysical survey of the site (Parsons ES, 1995a).

Ten samples were taken at three depths in each of three borings (SB1 through SB3) at B-19 (Table B19-1) (Parsons ES, 1995c). Boring locations are shown in Figure B19-1. Each sample was analyzed for metals, VOCs, and SVOCs. The results of the analysis are summarized below:

VOCs: None detected.

SVOCS: Di-n-butylphthalate was identified in eleven samples.

Metals: Lead was within background concentrations. Cadmium concentrations may have exceeded background levels in five instances. Note: Since this plan was submitted, background concentrations have been revised.

The method used for analyzing cadmium could not measure concentrations to within the background level of cadmium in the Glen Rose limestone. Therefore, cadmium may or may not have exceeded background limits and should be analyzed again. See note above.

Six borings were drilled at B-19. In the first three boreholes, drilled during dry weather, only one borehole contained groundwater. During the second three drillings, perched groundwater was observed all three borings at 21.5, 5.10, and 20.12 feet bgl. However, the area received rain shortly before the borings were drilled and water was able to infiltrate the boreholes. In one of the second group of water samples, PCE was detected at a concentration of 0.007 mg/l. Results are summarized in Table B19-2.

Data Needs: Analysis of cadmium and SVOCs for all surface and subsurface soil samples, and PCE concentration in groundwater, if located. Results of other SVOC analytes, from the previous investigation, were rejected due to deficiencies in quality control criteria.

Closure Activities: The following field activities will be performed to gather data for TNRCC closure submittal of SWMU B-19.

Review historical records as described in Section 2.4.1 of the Work Plan Overview.

Locate and receive approval for three soil borings at the approximate locations shown on Figure B19-1 as described in Section 2.4.1 of the Work Plan Overview. Because previous boring B19-SB2R contained some water, one boring will be located adjacent to the old boring location to maximize the probability of finding perched water.

1. Three soil borings will be drilled to characterize the subsurface soils.

1. Drill the three soil borings in the approved locations as described in Section 2.4.1 of the Work Plan Overview.

2. Obtain three samples per boring near the surface (0-2 foot depth), middle, and total depths as described in Section 2.4.1 of the Work Plan Overview.

3. Sample and analyze for di-n-butylphthalate (identified in previous investigations) and cadmium (as outlined in the FSP).

2. Water is not expected to be encountered at the site. However, if water is discovered in any of the soil borings, all three borings will be sampled and potentially completed as groundwater monitor wells as detailed in Section 2.4.1 of the Work Plan Overview. Sample groundwater, where present, and analyze each sample for VOCs and metals (as outlined in the FSP).

3. Handle the IDW in accordance with the FSP.