A.16 Fox River and Green Bay, WI 2013

A.16.1 Summary

Environment:	Freshwater
Scale:	Full
Contaminants of Concern:	PCBs, OU 2: >50 ppm, OU 3: >50 ppm, OU 4: >50 ppm, OU 5: >1.0ppm, Dioxin, Furan, DDT heavy metals: arsenic, lead, and mercury Dioxin, furan, DDT, and heavy metals not targeted.
Final Remedy:	Disposal information will be defined once dredging has begun. The proposed plan is to dewater the sediment and transport dried sediment to off-site landfills in Illinois or Michigan.

A.16.2 Site Description

Year, projected:

• OUs 2 and 3: 2013
• OUs 4 and 5: 2017

Water depth: 6-20 ft

These sites contain 12 dams and 17 locks. The contaminated sediment areas are 33 miles and 1,600 sq. miles, respectively.

Target Volume, total combined: 3.5 million yd³

Contaminated sediment depth:

• OU 2: 40 inches of sediment
• OU 3: 7.5 ft
• OU 4: 13 ft.

A.16.3 Remedial Objectives

• PCBs: 1.0 ppm
• SWAC of 0.25 ppm PCBs in the upper 10 cm of sediment

A.16.4 Remedial Approach

Mechanical dredging will be used. OU 2 (Appleton to Little Rapids Dam. 20 mile stretch) and OU 5 (1,600 miles of Green Bay) will use MNR.

A.16.5 Monitoring

Resuspension: The extent of dredging will be monitored for resuspensionA renewed suspension of insoluble particles after they have been precipitated. and measures may be put into place to contain suspended contaminants depending on the type of dredging.

Residuals: Post-removal sampling and surveying to determine whether sediment removal objectives were met, if not; re-dredging if greater than 10 ppm or backfilling if less than 10 ppm.

An engineered capA covering over material (contaminated sediment) used to isolate the contaminants from the surrounding environment. will be used for areas where dredging could damage riverbank (estimated 450 acres).

Sand covers where the maximum PCB level is less than 2 ppm and where the contaminated sediment layer is no thicker than 6 inches.

RAOs/project objectives achieved? Work is in progress on these sites.

A.16.6 References

U.S. EPA. Record of Decision Amendment Operable Unit 2 (Deposit DD), Operable Unit 3, Operable Unit 4, and Operable Unit 5 (River Mouth). June 2007. http://www.epa.gov/superfund/sites/rods/fulltext/a2007050002100.pdf.

U.S. EPA. First Five-Year Review Report for Fox River NRDA/PCB Releases Site. July 2009. http://www.epa.gov/superfund/sites/fiveyear/f2009050002959.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