A.17 Gill Creek, NY

A.17.1 Summary

Environment:	Freshwater
Scale:	Field
Contaminants of Concern:	VOCs, Mercury, PCBs: 11,000 ppm
Final Remedy:	Hydraulic and mechanical dredging using cofferdams and sandbags for to dewatering. Sediment was stabilized with fly ash and kiln dust then transported to an RCRA and TSCA permitted landfill. 230 yd3 was deemed hazardous and was incinerated.

A.17.2 Site Description

The site is owned by E.I. DuPont and consists of a 250-foot sector of creek near its confluence with the Niagara River.

Year: 1992

Target Volume:

• Area 1: 3,400 yd³
• Area 2: 160 yd³
• Area 3: 40 yd³

Actual Volume Removed: 8,020 yd³

A.17.3 Remedial Objectives

• BHCs: 0.045 ppm
• PAHs: 22 ppm
• Mercury: 0.2 ppm

A.17.4 Remedial Approach

Only sites OU 3–OU 5 were dredged. A compacted clay liner was installed to prevent groundwater seepage into creek.

A.17.5 Monitoring

Contaminant concentrations were significantly lower after dredging. No cappingTechnology which covers contaminated sediment with material to isolate the contaminants from the surrounding environment. was required for this site. Post-remediationThe act or process of abating, cleaning up, containing, or removing a substance (usually hazardous or infectious) from an environment. monitoring was planned for 5 years, consisting of sediment and water sampling.

RAOs/project objectives achieved? Based on confirmatory sampling, cleanup levels were met. A long term monitoring plan is in place to assure the protection of human health and the environment.

A.17.6 References

U.S. EPA. Realizing Remediation II An Upland Summary of Contaminated Sediment Remediation Activities at Great Lakes. July 2000. http://www.epa.gov/glnpo/sediment/realizing2/RR2report.PDF.

Major Contaminated Sediment Sites Database; Sept. 2004 as updated 2008. http://www.smwg.org/MCSS_Database/MCSS_Database_Docs.html.

Publication Date: August 2014