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SAP Addendum Specific to Off-Post Groundwater Sampling Activities under AETC Delivery Order 5084

Revised July 2001

1.0 - Introduction

This document is a revised addendum for modification two of the subject delivery order that modifies the Sampling and Analysis Plan (SAP) for SWMU Closures at CSSA (Environmental Encyclopedia Volume 1-4, Field Sampling and Analysis Plan tab and QAPP tab) for the off-post monitoring wells as specified in AETC Delivery Order 5084. The purpose of this addendum is to address changes to the existing SAP relating to the off-post sampling activities.

2.0 - Off-post Groundwater Sampling Overview

The primary objective of the off-post groundwater monitoring is to determine concentrations of chlorinated VOCs that may be present in off-post wells. A secondary objective of the off-post sampling is to determine the potential extent of off-post contamination. A subsidiary objective of the off-post quarterly sampling is to assess whether there are apparent trends (decreasing or increasing) in contaminant levels over time in the tested wells.

The current objectives of the groundwater monitoring program, in general, are to determine groundwater flow direction and water levels, determine groundwater contaminant concentrations for characterization purposes, and identify seasonal variations in physical and chemical properties. Overall DQOs for the investigations at CSSA are provided in Volume 1-1 behind the RFI Addendum tab (Section 11). A list identifying the DQOs for CSSA�s groundwater monitoring program includes:

Conducting groundwater sampling in accordance with procedures defined in applicable work plans, the SAP, QAPP, and HSP;

Preparing water-level contour maps;

Describing the flow system, including the vertical and horizontal components of flow;

Identifying any temporal changes in hydraulic gradients due to season influences;

Characterizing the horizontal and vertical extent of any immiscible or dissolved plume(s) originating from the Facility;

Determining the horizontal and vertical concentration profiles of all constituents of concern in the groundwater that are measured by USEPA-approved procedures;

Meeting AFCEE QAPP quality assurance requirements;

Comparing useable data to closure standards and/or cleanup criteria under all applicable regulations for the Facility; and

Evaluating quarterly data for contaminant concentration trends.

2.1   Procedures for Sampling Activities

Four rounds of groundwater samples will be collected from 20 off-post private and public wells, located outside the perimeter of the CSSA facility. The actual wells to be sampled will be identified by CSSA. Data from this sampling will be incorporated into six quarterly groundwater monitoring technical reports. The format of the technical reports will be developed by CSSA.

One modification is needed for the groundwater sampling methodology described in Section 2.1.5 of the SAP, to accommodate off-post sampling from private wells, as follows.

After contacting the property/well owner, and scheduling the sampling visit, the procedures for collecting an off-post groundwater sample will be:

  1. Locate the tap closest to the well. If a water softener or filters are present, then they must be turned off, or the tap to be sampled must be located before the water is processed by these items.

  2. Run the water from the tap for 5 minutes prior to sample collection to purge the existing service lines.

  3. Collect the water sample directly from the tap, and not from garden hoses or other devices.

2.2   Contaminants of Concern and Analytical Methods

Constituents of concern for off-post groundwater monitoring include volatile organic compounds (VOCs). Each sample will be analyzed by USEPA Method SW8260B for the short list approved by the USEPA for CSSA, to include 1,1-dichloroethene (DCE), bromodichloromethane, chloroform, cis-1,2-DCE, dibromochloromethane, methylene chloride, trans-1,2-DCE, tetrachloroethene (PCE), trichloroethene (TCE), and vinyl chloride. QA/QC sampling and analysis will also be performed to meet the requirements of the AFCEE QAPP and the SAP.

3.0 - Data management Process

A process for collecting and entering data into electronic formats was developed specifically for the data collection activities under this delivery order. The key component of the data collection process is use of a Trimble ProXR/XRS Receiver with the TSC1 Data Logger, and the associated Pathfinder Office Software and the use of an electronic chain of custody. The general details of this process are listed below.

  1. A data dictionary will be created in Trimble Pathfinder Software that will include the site identification (siteid), location identification (locid), pH (pH), conductivity (cond), water temperature (temp), date, time, and remarks.

  2. The off-post groundwater sample will be collected as described in the SAP and this SAP addendum. Data collected in the field (siteid, locid, pH, cond, temp, and remarks) will be entered directly into the Trimble unit. Date, time, and coordinates are automatically generated by the Trimble unit.

  3. The off-post groundwater samples will be labeled by a sample numbering system, used as a tracking mechanism to allow retrieval of information about a particular location and to assure that each sample is uniquely numbered. The procedure outlined in the FSP will be used.

  4. Analytical testing requirements and sample information will be entered into an electronic chain of custody that will be shipped to the laboratory with the associated sample cooler.

  5. At the conclusion of each day, the data in the Trimble unit will be downloaded into a computer at CSSA utilizing the Trimble software. It may be necessary to correct the locational data using differential calculations during the downloading process.