[Home]

[SWMU B-33]

SWMU B-33 Work Plan Addendum

RL33 Project, March 1998

Known (Updated): Approximately 325 feet of active water pipe (2-inch PVC) west of Building 45 is bedded in lead-contaminated sand containing shot which was generated at the Building 90 test firing room. It is estimated that the bedding extends to a depth of approximately 3 feet and is approximately 2 feet wide. The B-33 unit consists of the bedding material only.

Previous Investigations (Updated): Surface soil and subsurface soil samples were collected at B-33 in March 1996 and May 1997, respectively. Sample locations are shown in Figure B33-1. Analytical results are in question due to ITS Laboratory’s practices.

Data Needs: As mentioned previously, the extent of pipe bedding that consists of shot and lead-contaminated sand needs to be determined, and the shot and associated contaminated material needs to be decontaminated/remediated. It is estimated that approximately 100 cubic yards of contaminated material needs to be decontaminated/remediated. It is planned that excavated material will be characterized and disposed of, as described in the waste analysis plan.

Closure Activities: Shot and lead-contaminated sand making up the pipe bedding at B-33 was excavated, and will be characterized and disposed of.

1. CSSA personnel diverted the water line to allow excavation underneath the pipe.

2. Shot and lead-contaminated sand was removed with a backhoe and manually with a shovel where necessary. Material was placed on plastic sheeting, bermed, and covered.

3. A LeadCheck^® field test kit was used to determine if elevated lead levels occur in the underlying soil. The test kit can only identify lead in soil at concentrations of 400 mg/kg or greater; therefore, samples for laboratory analysis were also collected. The field test kit was used solely as a rough field check to determine if additional contaminated soil need to be removed. The contaminated soil were removed until the field test kit indicated that additional excavation is not necessary. The target cleanup levels are the background values for the Krum Complex and Brackett-Tarrant association.

4. CSSA personnel backfilled the trench with clean fill sand.

5. To determine if all shot and lead-contaminated soils have been removed, confirmation soil samples were collected at a rate of approximately one per 100 linear feet of pipe bedding. These metals were shown during previous investigations to exceed background concentrations. These samples were analyzed for copper, lead, mercury and zinc using methods listed in the table below.

The methods to be used to stabilize the waste prior to disposal are described in the Waste Analysis Plan.