Known: SWMU B-34 is the pipe and pipe bedding for a 230-foot section of pipe leading from a locomotive maintenance pit southwest underneath an open field to an outfall opening near a culvert at McElroy Road. The locomotive maintenance pit reportedly drained through the pipe into a ditch leading directly to Leon Creek (ES, 1993b). The drain has been closed. Only the pipe and bedding constitute the unit.

Previous Investigation: In March 1996, a geophysical survey was conducted at the site. One geophysical anomaly not associated with waste management practices was observed.

Three surface soil samples were collected on 11 March 1996 and analyzed by ITS Laboratory for VOCs, SVOCs, and metals. In addition, three soil borings were completed and six soil samples were collected (two samples from each boring) on 22 and 23 August 1996. These subsurface soil samples were analyzed by ITS Laboratory for VOCs, SVOCs, and metals. A large oak tree prevented drill rig access to the B34-SS3 surface soil sample location, therefore the soil boring B34-SB3 was relocated and surface and subsurface sample were taken approximately 30 feet north of the surface sample.

Planned Rework: Replace previous analytical chemistry data generated by ITS Laboratory. To accomplish the replacement of ITS data, Parsons ES proposes three soil borings located as close as possible to the suspected pipe bedding material. These borings will be named RW-B34-SB1, RW-B34-SB2, and RW-B34-SB3. Three samples from each boring (surface, trench bottom and total boring depth) will be analyzed for VOCs, SVOCs, and metals. Additionally, a surface sample from the original location of B34-SS3 will be collected for VOC, SVOC and metals analyses. The surface sample will be named RW-B34-SS3.

Rationale for Analytical Program: SWMU B-34 consists of pipe bedding form a locomotive maintenance pit. Therefore, 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. Explosives are not included in the analysis since ammunition is not included in the pipe bedding material.

Resampling Activities: The following field activities will be performed to gather data for TNRCC closure submittal of SWMU B-34:

1. The boring logs from the original drilling of SB1, SB2, and SB3 will be copied and reviewed by the supervising geologist prior to beginning any rework at SWMU B-34. 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 first set of soil borings, completed in 1996. Boring and surface soil sample locations are shown in Figure B34-1. The rework soil samples will be collected from each boring from the same depth intervals as the first set of surface and 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. The total depth of each boring will be at approximately the same depth as the first set of soil borings (SB1 = 12.9 feet, SB2 = 10 feet, and SB3 = 13.8 feet BGL). Each rework sample will be analyzed for VOCs, SVOCs, and metals, as indicated in the table below. Metals include arsenic, barium, cadmium, chromium, copper, lead, mercury, nickel, and zinc. 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 monitoring wells is not included in the scope of the rework as no 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 and submitted 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.

Historical Analytical Program and Rework Sampling Plan (highlighted in bold)