In accordance with the Operable Unit V Record of Decision, soils containing the contaminants of concern, cesium-137 and mercury, were excavated from the Sewage Treatment Plant and transported offsite to licensed disposal facilities. Excavated areas were back-filled with clean soils.
Following remediation, a final radiological status survey was performed to demonstrate that residual radioactivity in each area satisfies the cleanup criteria identified by the Record of Decision. In addition, the Oak Ridge Institute for Science and Education (ORISE) performed an independent verification survey to confirm that clean-up goals were achieved.
Approximately 845 cubic yards of soil and debris (including plastic liner, concrete, brick, and clay tile pipe) were excavated as low-level radioactive waste. Approximately 475 cubic yards of additional soil, considered non-hazardous waste, were also excavated. The waste soil and debris were transported by rail to a designated disposal facility.
In July 2003, the closeout report for this remediation project was submitted to the regulatory agencies for approval.
|06/02: Operator Kerry Botts makes precision cuts to scoop up mercury-contaminated soil along the top six inches. The area being excavated is 10 feet wide by 30 feet long, and was sampled as having mercury content at the top six inches.|
|07/02: Dust control is managed on hot, dry days by misting the cleanup area.|
|07/02: Many of the pre-excavation samples were collected and split with the Suffolk County Department of Health Services for comparison of analytical laboratory results|
|07/02: Workers wrap excavated soil prior to transport to an approved offsite disposal facility.|
|11/02: Workers take additional samples in November 2002 at the Sand Filter Beds|
|01/03: Track excavator removes soil from a sand filter berm and loads it in a dump truck for transport to the soil pile storage area (in background).|
|Summer 03: one of the excavated areas backfilled with clean soil.|