On September 25, 2018, the U.S. Environmental Protection Agency (USEPA) issued a Record of Decision for Operable Unit 8 (OU8), commonly referred to as Impoundments 1 and 2. The final remedy is based upon a comprehensive Focused Feasibility Study, input from EPA’s National Remedy Review Board, a detailed analysis of the alternatives, and public comments. The major components of the remedy selected by EPA include the following:
- Excavation and dewatering of the impoundment material from Impoundments 1 and 2;
- Emission and odor control measures to protect workers and the surrounding community;
- Off-site shipment of the excavated material for treatment/destruction;
- Collection of the dewatered aqueous phase liquid for either on-site treatment and discharge or for offsite disposal;
- Treatment of any impacted soil and/or clay in the impoundments with concentrations above remediation goals via in-situ stabilization and solidification (ISS);
- Backfilling the excavated areas with existing berm materials from the impoundments not requiring treatment;
- Installing a protective cover over the entire OU8 footprint; and
- Implementing institutional controls, monitoring, and periodic reviews to ensure that the remedy remains protective of public health and the environment.
USEPA and Wyeth Holdings LLC (WH) executed an Administrative Order on Consent on September 30, 2019 authorizing WH to move forward with design and implementation of the remedy as described in the Record of Decision.