Brookhaven, NY

A.5 Brookhaven, NY

A.5.1 Summary

Environment:	Freshwater
Scale:	Full
Contaminants of Concern:	Hg: 39.7 ppm max, Ag: 380 ppm max, Cu: 1490 ppm max, PCB (aroclor-1254): max 1.5 ppm
Final Remedy:	A sediment-drying pad was constructed to dewater sediment prior to disposal. Water was treated at a separate unit before going back into the river. On-site, 60 ft x 60 ft wet cells used to decant the sediments. Contaminated sediment was deposited at a landfill.

A.5.2 Site Description

The Brookhaven National Laboratory (BNL) site is located along the Peconic River in Suffolk County, New York. The site and site remediationThe act or process of abating, cleaning up, containing, or removing a substance (usually hazardous or infectious) from an environment. are described in the site close-out report (Envirocon 2005). Approximately 14,025 linear feet (2.66 miles) of the Peconic River was contaminated. Water depth at the site was approximately 0–30 ft, the target volume for removal was 1134 tons, and the actual volume removed was 1134 tons.

A.5.3 Remedial Objectives

The remedial objectives for this site included:

SWAC: Less than 1 ppm Hg for entire BNL property; less than 2 ppm Hg for remediated area
contaminated sediment thickness of 1 ft

A.5.4 Remedial Approach

Partial dry excavation was achieved with mechanical excavators working from timber crane mats. Excavators were equipped with flat blade buckets. Cleanup achieved remedial objectives by reducing average Hg concentration outside Brookhaven National Laboratory property to 0.092 ppm with all samples less than 2 ppm.

The dredged area that had been a marsh was backfilled with 6–12 inches of clean river sediment for restoration. MNR is in effect to restore the marsh environment. One silt barrier was placed at northern most region to prevent further migration of contaminants.

A.5.5 Monitoring

A long-term monitoring plan is in place to assure the protection of human health and the environment. Very few details are available for resuspensionA renewed suspension of insoluble particles after they have been precipitated. monitoring.

RAOs/project objectives achieved? Based on confirmatory sampling, cleanup levels were met.

A.5.6 References

EPA Superfund Record of Decision: Brookhaven National Laboratory (USDOE). USEPA ID: NY7890008975. Jan 2005. http://www.epa.gov/superfund/sites/rods/fulltext/r2005020001410.pdf.

Environcon, Inc. Final Closeout Report Peconic River Remediation Phases 1 and 2 Brookhaven National Laboratory. Aug 2005. http://www.bnl.gov/gpg/files/Closeout_reports/PR_Closeout_Report_v1.pdf.

Brookhaven National Laboratory. Final Five-Year Review Report for Brookhaven National Laboratory Superfund Site. July 2006. http://www.epa.gov/superfund/sites/fiveyear/f0602019.pdf.

Publication Date: August 2014

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