Lower Sasa fuel burning pond wetland

Department of Navy

This report presents the proposed approach for the reevaluation of risk to the Mariana common moorhen at the wetlands associated with the former Lower Sasa Fuel Burning Pond in Piti, Guam. The site encompasses a former fuel burning pond, a former deballast facility, and surrounding wetlands. Wastewater from the pond was discharged into the adjacent wetlands to the north. Subsequent to the completion of the SERA, wetlands north of and adjacent to the site were enhanced to provide habitat for the endangered Marian common moorhen. Moorhens are now expected to occur in the wetlands adjacent to the site. The Navy will conduct a Tier 2, Step 3a Baseline Ecological Risk Assessment (BERA) using existing site information and refined exposure assumptions. A Tier 1 Screening Ecological Risk Assessment (SERA) was completed by the Navy in August 2001, which assessed the potential for adverse effects to the moorhen at the site. The site failed the screening, and the data quality and exposure assumptions were questioned by the United States (U.S.) Environmental Protection Agency (EPA) and the U.S. Fish and Wildlife Service (USFWS). As a result, the Navy and regulatory risk managers decided to move the investigation to Tier 2 (BERA) for further evaluation. This document presents the proposed approach for Tier 2 and the proposed revised exposure assumptions (Step 3a) for regulatory review and concurrence.