2005 Remedial Options Pilot Study

Overview

The Remedial Options Pilot Study (ROPS) was performed between April and December 2005 to provide information pertaining to potential remedial alternatives for addressing contaminated sediments in the lower Grasse River. The ROPS was conducted by Arconic (formerly Alcoa) with oversight from the United States Environmental Protection Agency (EPA; lead), New York State Department of Environmental Conservation (NYSDEC), and the St. Regis Mohawk Tribe (SRMT). This group has been working together to develop a comprehensive clean up approach to address the sediments in this area of the river that are impacted by polychlorinated biphenyls, or PCBs, and the ROPS is part of this collaborative process. ROPS construction activities consisted of a combination of removal and capping activities, including:

  • Sediment removal by dredging and capping in the main channel and adjacent northern side slope area;
  • Sediment removal and capping in the northern near shore area;
  • Thin-layer capping in the southern near shore area; and
  • Armored capping in the main channel. The targeted location of each component of the project is shown on the figure below.

These components were selected and developed to build upon previous work and address outstanding issues associated with the evaluation, selection, and effectiveness of a final remedy. Details on the ROPS components are presented below.

ROPS

Intensive monitoring activities were conducted prior to, during, and after construction, with longer-term monitoring activities completed in 2006 and 2007. Information gained from the ROPS will ultimately be utilized in the development of the revised Analysis of Alternatives Report for the Grasse River, which will serve as the basis for the selection of a final remedy for the site.