Anaconda Wetland Area Delineation

The Atlantic Richfield Company completed a study for the Anaconda Regional Water, Waste and Soils Operable Unit as part of a larger study of the entire Superfund site. This study included: 1) an inventory of areas where jurisdictional wetlands occur; 2) an evaluation of wetland functional value and determination of FEWA; and 3) an inventory of threatened, endangered, and sensitive plant and animal species within the project area.

Pioneer personnel played a key role in a cooperative effort to conduct the follow-up delineations, FEWA assessments, prepare remedial action design documents, and conducting post-construction FEWA credit review. The Anaconda Regional Water, Waste and Soils Operable Unit wetlands consist of the following four-step Upper Clark Fork River (UCFR) Wetland Mitigation process: (1) wetland identification and delineation; (2) preliminary analysis of impacts; (3) detailed analysis of impacts; and (4) confirmation of response action impacts.

The goal of this process is to meet the substantive requirements of Executive Order 11990 (“no net loss” policy) and Section 404(b) of the Clean Water Act during the course of remedial actions on the UCFR Superfund sites. In addition to the identification and delineation of jurisdictional wetlands, Step 1 includes a functional evaluation of a wetland to determine FEWA (defined as delineated wetland acreage adjusted by an overall rating for functional value).