Derecktor Shipyard Cleanup Plan Involves Dredging

Derecktor Shipyard Cleanup Plan Involves Dredging

EPA in cooperation with the U.S. Navy and R.I. Dept. of Environmental Management (RIDEM) has completed two “Records of Decision” (RODs) approving cleanup remedies of contaminated areas at the Derecktor Shipyard which is part of Naval Station Newport, formerly known as the Naval Education and Training Center, in Middletown, R.I.

The two contaminated areas targeted for cleanup under these two RODs include both an offshore area and onshore area of the Shipyard. While EPA will be overseeing the implementation of these remedies, actual field work will be conducted and paid for by the Navy and their contractors.

EPA, RIDEM and the Navy have worked cooperatively to meet these important milestones, which will lead to a cleaner environment in Narragansett Bay,” said Curt Spalding, regional administrator of EPA’s New England office. “We are looking forward to continuing the cleanup work at this site.

Investigation into the nature and extent of contamination in the soils and groundwater at the Derecktor Shipyard on-shore and off shore areas revealed elevated levels of trichloroethylene, polycyclic aromatic hydrocarbons, and metals. The selection of the two remedies for cleanup work at Derecktor Shipyard culminates over twenty years of investigation.

Scope of the cleanup

Derecktor Shipyard Onshore Remedial Action:

The remedy for the onshore component addresses soil and groundwater. The soil component of the remedy has been divided into three subareas: the Northern Waterfront, the Central Shipyard Area, and the Southern Waterfront. The soil remedy includes new soil covers, re-pavement, and Land Use Controls (LUCs). The LUCs will restrict the parcel to industrial land use and require maintenance of monitoring wells throughout the onshore area.

The LUCs also require maintenance of the new and existing soil covers and pavement in the Central Shipyard Area to prevent exposure to subsurface soil. Pre-design sampling is required to assess contamination in the North Waterfront Area from construction activities.

Interim LUCs will be established to prevent exposure to asbestos and sediment-related contaminants in the North Waterfront Area until the pre-design sampling determines whether contaminant risks are present above remedial goals. Long-term monitoring of the cover is required to ensure that contaminants remain contained.

Total estimated cost to implement soil and groundwater cleanup for the on-shore remedy: $2,231,900.

Derecktor Shipyard Offshore Remedial Actions:

– dredging target open water areas (approximately 27,646 cubic yards), disposal of the dredged sediment at an offsite landfill;
– capping target sub-pier areas (approximately 83,574 square feet);
– confirmation sampling in dredged areas (and possibly adjacent areas) to ensure the cleanup goals have been met on an area average basis;
– establishing LUCs to ensure capped areas beneath Pier 2 will be protected or addressed if Pier 2 is ever reconstructed or demolished;
– monitoring the capped areas to ensure that contaminants left beneath Pier 2 do not migrate into the cap during placement and do not migrate after capping;
– establishing safe work practices in the LUC documentation that require future dredging and pier/waterfront maintenance and construction projects to consider the presence of potential asbestos to ensure that dredge spoils are handled appropriately;
– pre-design sampling to determine whether recent construction activities have modified any of the areas targeted for dredging; and
– reassessment every five years to ensure long-term protectiveness of the remedy.

Total estimated cost for implementation of the off shore remedy: $18,828,150.

Press Release, September 18, 2014