[Volume 1.4 Table of Contents]

January 1997

This document is an addendum to the Sampling Analysis Plan (SAP) for SWMU Closures at Camp Stanley Storage Activity (Parsons ES, 1996b). This addendum describes modifications and additions to the SWMU Closure SAP, and provides specific information appropriate and relevant to the field work at the B-20 site. Therefore, this SAP addendum only addresses the B-20 tasks.

Field work will generally proceed in the following order:

1. Mobilization and identification of the north and east boundaries;

2. Vegetation trimming (for UXO identification purposes), UXO surface sweep (visually and with use of a magnetometers), and collection of metal scrap, all in north and east extensions only;

3. Sample collection and field analysis for possible explosives contamination of surface soil where raw explosives are found.

4. Confirmation sample collection and laboratory analysis for explosives. Confirmation samples will also be analyzed for barium, cadmium, lead, and mercury.

5. Placement of soil identified as contaminated in 55-gallon drums;

6. Re-sample previous locations until elevated contaminant levels dissipate;

7. Sample 55-gallon drums for disposal purposes;

8. Detonate all additional UXO identified on site; and

9. Survey boundaries of north and east extensions.

Each of these tasks is described in detail below.

1.0 - UXO Sweep and Identification

The north and east extensions of the B-20 site will be cleared to aid in the identification and removal of UXO in those portions of the site. Due to previous identification of an endangered species (black-capped vireo) in the vicinity of the site, measures recommended by the USFWS will be followed, while still ensuring human safety. These measures are presented in a previous (December 1995) project plan addendum (Parsons ES, 1995c). Mature cedar trees will only be trimmed and surface vegetation cut, unless it is necessary to clear areas to ensure the safety of personnel identifying UXO. UXO identification subcontractors will clear the site under the supervision of Parsons ES.

UXO identification specialists will sweep and identify UXO materials within the northern and eastern extended boundaries. UXO identification will be accomplished visually and with the aid of a Schonstedt GA-52B Locator, a magnetometer which identified ferrous items up to a depth of 10 feet. Use of the magnetometer will ensure that UXO obscured by overgrown vegetation will be identified. The total area to be screened is approximately 37.5 acres (32 acres in north extension and 5.5 acres in east extension). If a UXO item is identified outside of the extensions or near the boundaries of the extensions, an additional 50 feet (as agreed at the October 19-20, 1995 meeting) will be swept for other UXO items. UXO screening will be conducted in accordance with the guidelines outlined in Section 4.3.1 of the Partial Facility Closure Plan (ES, 1994a).

UXO items, if determined to be safe to pick up, will be moved to a central location on site for later detonation. UXO that is identified as unsafe to pick up will be clearly identified with caution tape. Detonation of UXO is described in Section 4.0. All metal scrap (non-UXO) encountered during the surface sweep will be collected and containerized for recycling. UXO sweeping equipment and techniques will be the same as those used previously at the site. These equipment and techniques are described in greater detail in the Partial Facility Closure Plan (ES, 1994a) and the Remedial Investigation Report (Parsons ES, 1995a).

2.0 - Sample Location

An immunoassay field test kit will be used to semi-quantitatively identify possible explosive contaminated soil at locations at which raw explosive pieces are found. Soil that field-test positive will be placed into clean 55-gallon U.S. Department of Transportation (DOT) approved drums. The area will then be resampled until elevated explosives levels dissipate. Since explosives compounds generally have a high affinity for soil, areas that may be contaminated by explosive residue are expected to be small. Previous field testing of areas contaminated with raw explosives within the original boundary of the site showed that explosives contamination was generally limited to the soil immediately underlying the piece of bulk explosives (Parsons ES, 1996a). Field results of samples collected as close as one inch from the explosives location showed no sign of contamination.

The frequency of sample collection will be based on the amount of bulk explosives identified in the north and east extensions. If no bulk explosives are found, or there are no areas suspected of being contaminated with explosive residue, no samples will be collected.

One out of every ten field samples collected and screened will be sent for laboratory analysis (SW-8330) to provide data which can be compared to the field test results. These samples sent to the laboratory will also be analyzed for barium (SW-6010), cadmium (SW-7131A), lead (SW-7421), and mercury (SW-7471A). Sampling procedures, sample handling, and decontamination procedures outlined in Section 2 of the SAP for SWMU Closures (Parsons ES, 1996b) will be followed during sampling activities at the B-20 site.

Soil samples will be field screened with immunoassay test kits for TNT and Royal Demolition Explosive (RDX). Immunoassay technology for explosives compounds has been approved for field use by the EPA (Method SW-4050), and can be used for analyzing trace amounts of explosives. The D-Tech� system, or its equivalent, will be used for field screening. In the D-Tech system, an antibody specific for TNT and closely related compounds has been linked to solid particles which are collected on the membrane of a cup assembly. A color-developing solution added to the surface of the cup assembly develops a color inversely proportional to the concentration of TNT equivalents in the sample. TNT equivalents are measured as parts per million (ppm) in soil. Soil samples require a simple extraction step. A wide range of analyte concentration in samples is accommodated through conventional serial dilutions.

Step-by-step instructions provided by the manufacturer will be followed when conducting the field tests. A timing device will be used to ensure that Results are typically interpreted using a supplied color card. The D-Tech explosives test kit can be used to reliably measure TNT concentrations between 0.5 and 5.0 ppm. The minimum detection limit of the test for TNT in a soil sample is 0.5 ppm.According to the manufacturer, samples testing positive for TNT should be confirmed by standard methods due to the cross-reactivity of analogues and degradation products of TNT and other explosives (i.e., a positive test result may be due to the presence of TNT, cross-reactants or mixtures of explosives-related compounds). Cross-reactive compounds include:

Since the purpose of sampling during this investigation is to identify explosives-contaminated soil, laboratory testing of every sample with a positive detection will not be necessary. If there is a positive detection, the soil will be considered to be contaminated and will be drummed for disposal, as described below in Section 4.0.

Since the test kits are disposable, no decontamination of equipment, aside from the sample trowel, is necessary. Decontamination will follow procedures described in Section 1.5 of the Sampling Analysis Plan (Parsons ES, 1996b).

Samples collected for laboratory analysis (SW-8330) will be collected at a ratio of one per every ten field screened samples. The first duplicate sample will be collected early in the sampling effort, since the total number of field samples collected will be based on field observations. If the duplicate sample is collected on one of the first samples, laboratory comparison of the field test kits will be ensured.

The samples collected for laboratory analysis of explosives will also be analyzed for barium (SW-6010), cadmium (SW-7131A), lead (SW-7431), and mercury (SW-7471A). These metals have been detected at concentrations exceeding background within the original site boundary. Analysis of samples collected during this investigation will be used to determine if metals occur at concentrations of concern outside the site boundary.

Analytical techniques will follow procedures described in Test Methods for Evaluating Solid Waste, U.S. Environmental Protection Agency, SW-846 and the HQ AFCEE Quality Assurance Project Plan (QAPP) (AFCEE, 1996). All data will be reported in a manner which follows the AFCEE QAPP requirements.

As described in Section 2.4 of the SAP for SWMU Closures, four types of field QC samples will be collected during the investigative effort. QC samples to be collected include equipment blanks, field duplicate samples, and matrix spike/matrix spike duplicate (MS/MSD) samples. QC sample descriptions and identifications are described in detail in the SAP (Parsons ES, 1996b).

One equipment blank will be collected for every twenty soil samples collected, including samples which are analyzed in the field. Reagent grade water (ASTM type II) will be used for blanks.

Duplicate samples are described above, and will be only be collected as duplicates of the field test samples. Duplicates of laboratory samples will not be collected. One set of MS/MSD samples will be collected for every twenty soil samples sent to the laboratory.

3.0 - Detonation of UXO

Prior to scheduling the detonation of all UXO items found on site, Parsons ES will secure permission from TNRCC to conduct the blast. The U.S. Army Explosives Ordnance Detachment (EOD) will conduct the actual detonation. The UXO identification subcontractor and Parsons ES personnel will assist in preparing for the detonation. Prior to detonation, UXO items will be moved to a secure location in the B-20 area. This area will be properly marked and made accessible with caution tape. These items will be detonated once all additional UXO clearing activities have been completed. If any UXO item which cannot be moved safely is found, the surrounding area will be clearly marked, made inaccessible with caution tape, and the item will be detonated in place.

4.0 - Disposal of Waste

Wastes that may be generated during the UXO sweep at B-20 include scrap metal and contaminated soil. The scrap metal will be picked up as it is found and placed into a bin for recycling. If explosives-contaminated soil is identified though field testing, the soil will be placed in clean 55-gallon DOT-approved drums. The soil will be analyzed for leachable (TCLP) explosives and metals for disposal purposes. Additional analyses will be performed if the waste disposal subcontractor (as yet unidentified) requires. Applicable procedures described in Section 1.7 (Investigation-Derived Waste Handling) of the SAP (Parsons ES, 1996b) will be followed.