A.13 Fox River and Green Bay, WI 1998

A.13.1 Summary

Environment:	Freshwater
Scale:	Pilot
Contaminants of Concern:	PCBs, 45 ppm avg,186 ppm max, Mercury
Final Remedy:	Hydraulic cutterhead with swinging ladder used to dredge and sediment was dewatered, filtered. 905 tons (<50 ppm) taken to Winnebago County Landfill; 1,632 tons taken to E.Q. landfill (>50 ppm PCBs); 2,400 tons taken to Wayne Disposal.

A.13.2 Site Description

Year: 1998

Water Depth: 0–8 ft

Target Volume: 12,000 yd³ sediment

Actual Volume Removed: 8,200 yd³

Contaminated thickness: 2–3 ft

A.13.3 Remedial Objectives

Mass removal, demonstration

A.13.4 Remedial Approach

A hydraulic cutter head with a swinging ladder configuration was used. More minor dredging was done in 1999 to remove additional sediment at bedrock interface.

A.13.5 Monitoring

Resuspension: Six turbidity meters in river dredging area. Perimeter barrier of 80 mil HDPE, silt curtain around dredge sub-areas, 200 foot-long HDPE "deflection" barrier around industrial water intake, double-cased dredge discharge line.

Residuals: Post dredging: Surface sediments: 0.04–43 ppm PCBs, 16/19 samples >2 ppm. In 13/21 samples, post-dredge concentrations higher than pre-dredge

A.13.6 References

United States of America and The State of Wisconsin v. Appleton Papers Inc. and NCR Corporation Consent Decree. http://foxrivercleanup.com/bmos-resources/consentdecree801.pdf.

Record of Decision Operable Unit 1 and Operable Unit 2 Lower Fox River and Green Bay, Wisconsin Record of Decision Responsiveness Summary. Dec 2002. http://foxrivercleanup.com/bmos-resources/rod1.pdf.

Record of Decision Amendment Operable Unit 2 (Deposit DD), Operable Unit 3, Operable Unit 4, and Operable Unit 5 (River Mouth). June 2007. http://foxrivercleanup.com/bmos-resources/amendedrod.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