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[SWMU B-33 ]

RL17 & RL33 Work Plan Amendment for Data Quality Rework

SWMU B-33, May 2000

Known (Updated): Approximately 325 feet of active water pipe (2-inch PVC) west of Building 45 is bedded in lead-contaminated sand containing lead shot which was generated at the Building 90 test firing room. The bedding extends to a depth of approximately 3 feet and approximately 2 feet wide. The bedding and surface fill material was excavated, characterized, stabilized and properly disposed. The pipe bedding and surface fill were replaced with clean materials.

Previous Investigations (Updated): In March 1996, a geophysical survey was conducted at the site. Three surface soil samples were collected on 8 March 1996 and analyzed by ITS Laboratory for explosives and metals. In addition, three soil borings were completed and six soil samples were collected (two samples from each boring) on 14 August 1996. These subsurface soil samples were analyzed by ITS Laboratory for explosives and metals.

In July 1997, efforts to remove the sand and projectile material were conducted. Since the specific location of this material was not known, test pits were dug in an effort to find it. A total of four test pits were dug. One soil sample was collected from the sand pipe bedding of each pit. Field observations confirmed the presence of the lead shot material. The pipe bedding and fill material were removed and placed upon plastic for future disposition. The bedding and fill material were replaced with clean material and the sanitary sewer line returned to service.

In 1999, approximately 180 cubic yards of contaminated soil removed from SWMU B-33 was properly stabilized, as described in the Waste Analysis Plan and disposed of in an off-site municipal waste landfill.

Planned Rework: Replace previous analytical chemistry data generated by ITS laboratory. Parsons proposes that the rework sampling be focused on confirming that all contaminated material was removed during the excavation efforts. To accomplish this, complete three additional soil borings in the approximate locations of the previous soil borings and collect two samples from each boring. These borings will be named RW-B33-SB1, RW-B33-SB2, and RW-B33-SB3. Two samples from each boring (excavation extent and total boring depth) will be analyzed for metals and explosives.

Parsons ES proposes that surface and trench bedding samples collected at SWMU B33 not be repeated. Since the material was removed and properly disposed there should be no waste material left in place. Parsons ES proposes to use the analytical data of subsurface soils underlying the pipe bedding material to determine if all metals and explosives contaminated soils were actually removed.

Rationale for Analytical Program: SWMU B-33 consists of pipe bedding (sand and projectiles) from the Building 890 test range. Therefore, chemicals of potential concern include metals and explosives. Metals (arsenic, barium, cadmium, chromium, copper, lead, mercury, nickel and zinc) are included due to the metallic nature of the waste. Ammunition may include explosives residue therefore, an analysis for explosives will be conducted. SVOCs and VOCs are not included at this site since no evidence of waste burning has been found and there is no evidence of other waste disposal.

Closure Activities: The following field activities will be performed to gather data for TNRCC closure submittal of SWMU B-33.

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-33.

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. Collect samples from the previous extent excavation and at least five feet below the extent of excavation at each boring location. 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 borings completed in 1997 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 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 in not included in the scope of the rework as no wells were previously installed at the site.

6. Handle the IDW in accordance with 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.

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