This document is an addendum that modifies the existing WAP completed for disposal of wastes from SWMUs B-20/21, B-32 and B-33. This plan describes procedures that will be undertaken to obtain sufficient information to characterize waste from SWMU O-1 during IM activities.

This addendum to the SAP has been prepared to comply with all appropriate regulatory requirements of 30 TAC �335 for clean closure under Risk Reduction Standard Number 1. This plan describes the sampling procedure that will be implemented during closure activities to satisfy regulatory requirements.

Facility Description

A general facility description is included in the Installation Description and History section of the Background Information Report. A description of SWMU O-1 is included behind the SWMU O-1 tab in Volume 1-2 of the CSSA Environmental Encyclopedia.

Waste Analysis Parameters

Previous investigation and analytical results (see SWMU O-1 Links) indicate that material from SWMU O-1 would be characterized as a mix of potential hazardous and non-hazardous waste. The contaminants of concern are PCE, cadmium, and chromium.

Waste Management Activities

Waste management activities will be in accordance with the WAP, Addendum 2 specific to delivery order RL33 Sampling and Analysis Plan.

Waste Stabilization

Waste stabilization activities, if necessary, will be in accordance with the WAP, Addendum 2 specific to delivery order RL33 Sampling and Analysis Plan.

Waste Sampling and Analysis

Waste sampling and analysis activities will be in accordance with the WAP, Addendum 2 specific to delivery order RL33 Sampling and Analysis Plan. Information specific to the O-1 IM is provided below.

As previously mentioned, the contaminants of concern at SWMU O-1 include PCE, cadmium, and chromium. Analytical methods defined in Table 1 below will be used for the detection of these constituents. If the laboratory results from these analyses indicate that the soils are hazardous, those soils will be stabilized. If the soils are not hazardous, they will be disposed of as specified in the FSP. If stabilization is necessary, leachable constituents from waste or other materials will be a concern for the stabilized soils. These soils will be sampled by extraction, using method SW1311, as required by 268.7(a). These analytical techniques will follow procedures described in "Test Methods for Evaluating Solid Waste", U.S. EPA, SW-846 and the AFCEE QAPP.

Soils that are stabilized will be sampled at a frequency of one per 15 to 20 cubic yard batch to verify the success of the treatment. Over-excavated soils which are intended for off-site disposal and are not stabilized will be sampled at a maximum frequency of one per 50 cubic yards, or in an amount required by the landfill facility.

As previously mentioned, the contaminants of concern at SWMU O-1 include PCE, toluene, m,p-xylene, cadmium and chromium. Analytical methods defined in Table 1 will be used for the detection of these constituents. If the laboratory results from these analyses indicate that the soils are hazardous, those soils will be stabilized. If the soils are not hazardous, they will be disposed of as specified in Section 2 the FSP. If stabilization is necessary, leachable constituents from waste or other materials will be a concern for the stabilized soils. These soils will be sampled by extraction, using method SW1311, as required by 268.7(a). These analytical techniques will follow procedures described in "Test Methods for Evaluating Solid Waste", U.S. EPA, SW-846 and the AFCEE QAPP.

Special Procedural Requirements

Waste sampling and analysis activities will be in accordance with the WAP, Addendum 2 specific to delivery order RL33 Sampling and Analysis Plan.