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Evaluation of Background Metals Concentrations in Soils and Bedrock at CSSA

Section 1 - Introduction

1.1 - Purpose of Report

This report describes the field methods, results, and conclusions of the investigation conducted to determine background metals levels in soils and Glen Rose Limestone bedrock at Camp Stanley Storage Activity (CSSA) in Boerne, Texas.  This work was performed by Parsons, Inc. (Parsons), under contract to the United States Air Force (USAF) Air Mobility Command (AMC). 

This document represents an amendment to the Revised Evaluation of Background Metals Concentrations in Soils and Bedrock (Parsons ES, June 1997).  The previous evaluation was initially revised due to the questionable practices of the laboratory that analyzed the majority of the background soil samples used in the evaluation.  Further revisions were made based on decisions to combine data from eight soil types (as defined by the U.S. Department of Agriculture) into one large group of soil data, update the statistical methodology to meet current standards and accepted practices, and augment the background data set for Glen Rose Limestone. 

1.2 - Project Authorization

Parsons was contracted by AL/OEB to perform investigations at waste management units at CSSA under contract number F33615-89-D-4003, delivery order 126.  Subsequent revisions to this report have been made under contract F11623-94-D-0024 with AMC, delivery order RL17 due to questionable practices by the laboratory.

1.3 - Regulatory Basis

Current closure activities at solid waste management units (SWMUs) at CSSA are being conducted in accordance with federal and state regulations (40 Code of Federal Regulations (CFR) 265 Subpart G and Title 30 Texas Administrative Code (TAC) Chapter 335 Subchapter S, respectively).  The Texas Risk Reduction Rules, promulgated in 30 TAC 335 Subchapter S, establish comprehensive, risk-based standards for remediation of soil, groundwater, surface water, and air contamination.  These rules apply to all remedial actions undertaken in response to a release or spill of a solid waste or hazardous substance.  There are three alternate levels of environmental remediation:

  1. Risk Reduction Standard 1 (RRS1):  Closure/remediation to background;

  2. Risk Reduction Standard 2 (RRS2):  Closure/remediation to health-based standards and criteria; and

  3. Risk Reduction Standard 3 (RRS3):  Closure/remediation with controls.

Although the closure standard to be selected at each SWMU has not yet been determined, RRS1 (clean closure) will generally be the first choice.  Closure under RRS1 requires comparison of site contaminant levels to facility background levels or practical quantitation limits (PQLs), whichever is higher, for all environmental media.  This document provides the background metals concentrations for soils and Glen Rose Limestone at CSSA.

1.4 - Objectives and Scope

The objective of the background sampling and analysis is to provide a validated data set and statistically derived Upper Tolerance Limits (UTLs) for soils and the Glen Rose Limestone for use in SWMU closures or other work deemed necessary by CSSA.  To accomplish this objective, the following tasks were performed:

Established the background sample sets and collected samples from each set;

Performed validation of the background sample analytical data;

Statistically evaluated the analytical data for each sample set; and

Presented the results of the background sampling and analysis in this document.

This report is intended to be used as a reference document for future closure or other environmental activities at the post.  The ultimate purpose of this report is to establish background metal concentrations for soils and the Glen Rose Limestone at CSSA.

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