SAP Addendum Specific to Field Sampling Plan  Remedial Actions under AFCEE ENRAC TO 0019

Section 2 - Removal Action Activities

Based on results of Resource Conservation and Recovery Act (RCRA) Facility Investigations (RFIs) recently completed at CSSA, removal actions will be conducted at 16 SWMUs and AOCs to remove all waste or waste residue, required for Risk Reduction Standard 1 (RRS1) site closure. Affected soils will be removed from each site to depths where the remaining soil has site-specific contaminants of concern (COC) concentrations that are below background levels for COC metals or below reporting limits (RLs) for other site COCs.

2.1 - Site Clearing

Prior to soil removal activities at a SWMU or AOC site, any high grass, bushes, large debris, or small trees, that could potentially interfere with the excavation activities, will be removed from the site by the excavation subcontractor. When applicable, surface soils will be stockpiled at the edge of the site for potential later use as backfill for areas to be excavated at the site. To determine whether a stockpile is suitable (i.e., site COCs are below background values for metals or laboratory RLs for other compounds) as backfill, one soil sample will be collected for every 2000 cubic yards (CY) of soil. The sample would be analyzed for up to nine CSSA metals (arsenic, barium, cadmium, chromium, copper, lead, nickel, and zinc by Environmental Protection Agency (EPA) Method SW-6020 and mercury by EPA Method SW-7471) as a minimum and any additional site-specific COCs. If included in the list of COCs for the site, volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), and explosives would be tested by EPA Methods 8260, 8270 and 8330, respectively.

In addition to surface soils that would be stockpiled, testing will also include those soils removed from the side slopes to create a safe entry, if necessary, into an excavation and other soils including borrow soils from Covel Garden Landfill that could potentially be used as backfill. If reported sampling results for a soil source exceeds CSSA�s background level for metals or RLs for other constituents, the material may not be used as backfill and disposal would be required. Soil located at the Covel Gardens borrow source area has already been characterized and further analytical testing will not be required.

If ordnance-related materials are encountered, unexploded ordnance (UXO) specialists will be mobilized to the site and site activities will not resume until the area has been cleared by the UXO specialists. The UXO specialists will be mobilized to those sites that are known to have UXO prior to any excavation activities.

After a site has been cleared of vegetation that may interfere with the soil removal process and all UXO visible at the surface has been removed or made inert, the soil removal subcontractor will mobilize a backhoe or equivalent for the sampling of soils from the site for waste characterization purposes. Each soil sample will be a composite of discrete samples that are collected in accordance with the collection of composite samples described in Section 3.2 under sample collection procedures.

Based upon initial affected soil volume estimates determined from the investigation results and the known locations of anomalies, debris and any affected soils, the site will be divided into 1000 CY lots. One composite sample will be collected from each of the pre-designated 1000 CY lots. The samples will be sent to an analytical lab for analyses of total petroleum hydrocarbons (TPH) (Texas Method 1005) and Toxicity Characteristic Leaching Procedure (TCLP) Metals (EPA Method 1311 for the soil digestion and analyses of the extract by EPA Method 6010B for antimony, arsenic, barium, beryllium, cadmium, chromium, lead, nickel, selenium and silver and by Method 7471 for mercury). If the analytical results are reported below the acceptable limits for the Covel Gardens Landfill, then the soils from the lot with acceptable levels of TPH and the 11 metals will be excavated and placed into trucks for delivery to Covel Gardens. If the soils within a specific lot are identified as characteristically hazardous (40 Code of Federal Regulations [CFR] 261.24), then the soils will be treated with the stabilization procedure detailed in Section 3.2.3 (Bench Scale Testing) of the Environmental Cleanup Plan (ECP). After the soils have been treated, a second composite sample representing the subject 1000 CY lot will be collected and analyzed.

After the affected soils have been removed, confirmation samples will be collected from the base and side slopes of the excavation. The number of confirmation samples will be one per 100 linear feet of perimeter sidewall, with a minimum of one sample per sidewall. If the bottom of the excavation is bedrock, samples will be collected at a rate of one per 20,000 ft² of bottom surface area, with a minimum of two samples. If the bottom of the excavation is soil, samples will be collected every 100 feet (100-ft grids). Based on previous investigations at the various SWMUs and AOCs, approximate volumes of waste material have been estimated for most of the sites as shown in Table 2.1. The sites with no estimated volume are sites where initial or additional investigations are required to determine whether the site contains affected soils.

The samples will be analyzed for the nine CSSA metals (arsenic, barium, cadmium, chromium, copper, lead, nickel and zinc by EPA Method 6020 and mercury by EPA Method SW7471) as a minimum and any additional site specific COCs. If included in the list of COCs for the site, VOCs, SVOCs and explosives would be tested by EPA Methods 8260, 8270 and 8330, respectively. The list of constituents used to determine the possible presence of explosives is provided on Table 4.4.7-1 in Version 1.0 of the CSSA Quality Assurance Program Plan (QAPP). Samples will be analyzed by the laboratory on a standard 21-day turnaround basis.

Quality assurance/quality control (QA/QC) samples will be collected and analyzed along with the soil confirmation samples and will include: field duplicates (FDs), matrix spikes (MSs), matrix spike duplicate (MSDs), trip blanks (TBs) and equipment rinse blanks samples as necessary as per CSSA QAPP version 1.0. The frequency of collection for the above QA/QC samples is as follows: one FD per 10 samples, one MS/MSD per 20 samples, one TB per cooler shipment of VOC samples and one rinse blank per sampling method performed at the site. Full QA/QC will be performed on these samples and 100% of the results will be validated/verified by a chemist.

The analytical results for metals will be compared to the background values established in Second Revision Evaluation of Background Metals Concentrations in Soils and Bedrock at CSSA dated February 2002 and the analytical results for other COCs including VOCs, SVOCs and explosive-related compounds will be compared to the laboratory RLs. Further excavation may be conducted if any confirmation samples exceed CSSA�s established background concentrations for metals or RLs for other COCs. When the laboratory results have been received and there are no COC concentrations greater than the accepted background levels or RLs, the subcontractor will backfill the excavation with the clean soils that were stockpiled near the SWMU or AOC and grade the remediated area to match the grade of the surrounding area. If additional samples are necessary, a minimum of two additional confirmation samples will be collected after further excavation has been completed.

Additional information regarding these removal activities is included in Section 3 of the Environmental Cleanup Plan, Parsons, 2003.

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