Volatilization has been described in detail herein. Clearwater strongly urges EPA to specify of its contractors that all structures in which PCBs are stored or handled be enclosed, airtight, and maintained at a pressure slightly below ambient to prevent leakage of PCBs into the environment. Settling basins can be covered with floating membranes, and dredged spoils pumped directly beneath the membrane. All water treatment should be enclosed, and the removal of sediment from the settling basins accomplished through conveyors or other means that can be enclosed. EPA might consider the use of modular containers to transport materials from the handling buildings directly to the point of discharge into a TSCA-approved facility.
Containers offer the flexibility of being suitable for truck or rail, and are closed.
They can be returned empty without extensive cleaning, for savings of time and money. Even barges should be closed after filling for transport and layover. Clearwater believes that EPA should revisit treatment technologies. The quantity of gravel and backfill that must be mined will be reduced if decontaminated sediment can be put back in the river. New York Harbor, with its contaminated sediment problems, has provided a test-bed for treatment technologies.