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[SWMU B-19]

Solid Waste Management Unit B-19

RL17 Work Plan Amendment for Data Quality Rework, May 2000

Known: No geophysical anomalies associated with waste management practices were observed during geophysical survey activities on 3 February 1995.

Previous Investigations: Soil borings have been drilled at six locations during the course of two field efforts. Three soil borings were completed and nine soil samples were collected (three samples each boring) on 23, 24 and 27 February 1995. Each sample was analyzed for SVOCs, VOCs, and metals by Chemron, Inc. of San Antonio, Texas. Di-n-butylphthalate was reported in every sample, and chromium exceeded RRS1 in one sample. Due to a laboratory error, all three borings were re-drilled next to SB1, SB2 and SB3 to collect an additional VOC sample on 13 and 14 June 1995. These three additional borings were labeled SB1R, SB2R and SB3R. No VOCs were detected during the re-sampling effort by Chemron.

A groundwater sample was collected from SB3 on 28 February 1995, and three groundwater samples were collected from SB1R, SB2R and SB3R on 13 and 14 June 1995. These groundwater samples were analyzed by Chemron for VOCs only. A detectable concentration of tetrachloroethene was reported in SB2R borehole groundwater exceeding the RRS2-GW standard.

An additional three borings (SB4, SB5, and SB6) were completed between 30 August 1996 and 4 September 1996. These subsurface soil samples were analyzed by ITS Laboratory for contaminants exceeding background (RRS1) concentrations in the 1995 soil samples. At that time, these contaminants included di-n-butylphthalate and cadmium. However, since that time, background metals concentrations have been revised slightly, and only di-n-butylphthalate and chromium exceed what has currently been approved by TNRCC to be background. No groundwater was encountered during this investigation.

Planned Rework: Replace analytical chemistry data generated by ITS Laboratory. To accomplish this, complete three soil borings in the approximate locations of soil borings SB4 through SB6, and collect three subsurface soil samples from each boring. These borings will be named RW-B19-SB4 through RW-B19-SB6. Analyze samples for di-n-butylphthalate and chromium only.

Rationale for Analytical Program: Based on prior usage at the site as a "scrap" area to collect dirt and gravel and a disposal area for miscellaneous solid waste, metals and weapons, chemicals of potential concern include VOCs, SVOCs and metals. Metals (arsenic, barium, cadmium, chromium, copper, lead, mercury, nickel and zinc) are included due to the metallic nature of the waste. VOCs analysis is included in the analytical program to detect typical contaminants associated with a disposal area. SVOCs are included at this site since waste burning may have occurred.

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

1. The boring logs from the original drilling of SB4, SB5, and SB6 will be copied and reviewed by the supervising geologist prior to beginning any rework at SWMU B-19. In particular, the geologist will review the PID readings and recovery volumes obtained from the existing boring.

2. Field locate previous sample locations (collected in 1996).

3. Complete three soil borings in the approximate locations of the second set of soil borings (SB4, SB5, and SB6) completed in 1996. Sample locations are shown in Figure B19-1. The rework soil samples will be collected from each boring from the same depth intervals as the first set of subsurface soil samples, unless field instruments indicate that VOCs are present in the boring from a different depth. If PID readings indicate VOCs are present, then the subsurface soil sample from that interval will be submitted to the laboratory for analysis for VOC analysis also. The total depth of each boring will be at approximately the same depth as the original set of soil borings (SB4 = 34.9 feet, SB5 = 34.2 feet, and SB6 = 35.8 feet). Each rework sample will be analyzed for di-n-butylphthalate and chromium as indicated in the following table. VOC samples will be collected and analyzed if PID readings indicate the presence of volatile components in the soil/rock core. QA/QC samples will be collected as described in Section 2.4 of the FSP.

4. Boring logs for the rework soil borings will not be completed. Instead, the original boring logs created from the boring completed in 1996 will be available onsite during rework activities. Changes to the boring logs will be made if field personnel observe a difference in the rework boring from the original soil boring.

5. Water is not expected to be encountered in the borings at the site. However, if water is discovered in any of the soil borings, AFCEE and CSSA will be notified immediately. Completion of wells is beyond the scope of this rework as no monitoring wells were previously installed at the site.

6. Handle IDW as specified in the FSP.

7. Analytical results for the data quality rework samples will be reported in the Rework ITIR.

8. 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 in accordance with TNRCC closure requirements. If the site does not meet RRS1 closure requirements, a technical report describing the results of the investigation and recommended additional investigation and/or remediation will be prepared under the RL17 SOW.

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