The U.S. Army Environmental Center (USAEC) directed ABB Environmental Services, Inc. (ABB-ES), under Contract No. DAAA15-91-D-0008, to collect environmental samples at Fort Devens, Massachusetts to fill data gaps identified during initiation of the Feasibility Study (FS) for Group 1A sites. The Group 1A sites include the Shepley's Hill Landfill and Cold Spring Brook Landfill at Fort Devens. This Remedial Investigation (RI) Addendum report summarizes the supplemental field investigations, presents the data obtained, and updates the baseline risk assessment prepared for the RI report. Field investigation programs were conducted between September 1992 and July 1993 and included collecting and analyzing of sediment core samples from Plow Shop and Cold Spring Brook ponds, collecting and analyzing fish tissue samples from these two ponds, and conducting a macroinvertebrate study of the two ponds. In addition, several new monitoring wells were installed and groundwater samples were collected for analysis from 27 monitoring wells at Shepley's Hill Landfill and from 10 monitoring wells at Cold Spring Brook Landfill. Soil, sediment, and groundwater samples were also collected from several other areas, including Nonacoicus Brook Wetland and Grove Pond adjacent to Shepley's Hill Landfill, and the Magazine Area adjacent to Cold Spring Brook Landfill.

This data quality report provides an evaluation of method blanks, rinsate blanks, and field quality control sample data generated for the supplemental RI activities conducted at Fort Devens, Massachusetts. Data were generated by ESE Laboratories from the analyses of soil and water samples collected during the fall of 1992 through the Spring of 1993. Data from Round 2 groundwater sampling are contained in Section 3.0 of this Appendix. All data used in this report came directly off USAEC's IRDMIS system. Samples originated from study area Group 1A. Quality Control Frequency Tables. Frequency tables were generated for all quality control blanks that were analyzed during the Fort Devens RI. These include trip blanks, rinsate blanks and method blanks. The results are listed by analytical method and were used to identify any target analytes that appeared in the blanks. The frequency tables are provided to give an overview of blank contamination with respect to the number of blanks analyzed and the range of chemical contamination associated with each blank type. Tables 113, 114, and 115 represent the frequency of detected analytes for rinsate, method and trip blanks, respectively. Analytes which are not listed in the frequency tables were not detected at a concentration above the Certified Reporting Limit (CRL). They are listed, however, in Tables H6, H7, and 118. The frequency tables are arranged by QC type, method blanks, rinsate blanks, and trip blanks. Both method blanks and trip blanks were associated with their corresponding samples and evaluated following USEPA Region I Guidelines for data validation. Sample results that fell within either the 5X or lOX rule for blank contamination are listed in Table 1117. No results were eliminated or removed from the data set. The results were tabulated by method, sample ID, site, and lot for use in interpreting the data for the Remedial Investigation.