A.81 White Lake (OCC), MI

A.81.1 Summary

Environment:	Freshwater
Scale:	Full
Contaminants of Concern:	1996 concentrations averages: Total Chromium: 2,108 mg/kg Organic Chromium: 161 mg/kg Arsenic: 36 mg/kg Mercury: 1.6 mg/kg Tannery waste
Final Remedy:	Hydraulic cutterhead dredge and Barge Mounted Excavator. Dewatered on sectional barges and in Geotubes. The material was treated prior to disposal at an off-site landfill. Some areas were backfilled after dredging.

 

A.81.2 Site Description

Year: 2003

Water Depth: 10–15 ft

Target Volume: 76,000 yd³ 

Actual Volume Removed: 85,000 yd³ 

A.81.3 Remedial Objectives

Chromium concentrations less than 1,000 ppm.

Arsenic concentrations less than 20 ppm.

Contaminated sediment area: 6.2 acres of Tannery Bay

A.81.4 Remedial Approach

Hydraulic cutter head dredge, barge mounted excavator

A.81.5 Monitoring

Resuspension: Silt curtains were installed to control suspension. Turbidity monitoring was done outside silt curtains to ensure contaminates were not dispersing.

Performance: Vast amounts of tannery waste removed from site. Most contaminants stemmed from the tannery waste.

Residuals: Postdredging concentration before cappingTechnology which covers contaminated sediment with material to isolate the contaminants from the surrounding environment.:

Total Cr: 4463 mg/kg

As: 117 mg/kg

One year after dredging:

Total Cr: 2716 mg/kg

Organic Cr: 58 mg/kg

As: 30 mg/kg

Hg: 2.0 mg/kg

A.81.6 References

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

Great Lakes Areas of Concern; as updated July 2012. http://www.epa.gov/greatlakes/aoc/whitelake/index.html.

Publication Date: August 2014