Human Health Risk Assessment – EPA RCA II

Overview:

• GIS development and implementation
• Data management system development
• Community relations support
• PRP negotiations assistance

Description:

On 1 January 2019, Bluestone purchased Avatar Environmental, LLC. Avatar (now part of Bluestone) has been the lead risk assessment group providing support to the US Environmental Protection Agency (USEPA) on a 10-year ID/IQ type Small Business Remedial Action Contract (RAC).Under a TO for the RAC, we managed and conducted an HHRA for the Anniston PCB site, Operable Unit 4 (OU-4). OU-4 encompasses a 35-mile length of the Choccolocco Creek, including the backwater area and upstream on Snow Creek to Highway 78, and includes over 6,000 acres of Choccolocco Creek floodplain.

The Anniston PCB site refers to the area where PCBs associated with releases or discharges associated with operations of the Anniston Plant by Solutia Inc. (previously Monsanto Inc.), have come to be located. In addition to performing the HHRA, we also provided community relations support, sampling strategy support as well as sampling oversight, GIS development and implementation, land use surveys, PRP negotiations assistance, data management system development, and overall project management.

Through the course of the assessment, we investigated the potential health effects associated with exposure to PCBs through consumption of fish obtained from the Choccolocco Creek, direct contact with contaminated floodplain soil, and consumption of locally-raised agricultural products and livestock. The Team then further evaluated the fish ingestion pathway for potential risks to anglers and their families that catch fish from the Choccolocco Creek. This pathway evaluated the exposure at nine locations along the Creek and from three types of fish species. The Team also evaluated potential exposure to contaminated floodplain soil and identified 25 Exposure Units within OU-4 based on property ownership, land use, and levels of PCB contamination. Risk assessments were performed for each Exposure Unit. Finally, we evaluated potential exposure to beef and dairy cattle and chickens raised in contaminated floodplain areas by modeling uptake in animal feed crops such as grain, silage, and grasses, as well as uptake into animals through incidental soil ingestion.