OSWER/OSRTI 

Washington, DC 20460 

NATIONAL PRIORITIES LIST (NPL)

***Proposed Site*** March 2010 

ST. CLAIR SHORES DRAIN St. Clair Shores, Michigan 

Macomb County 

 Site Location: 

The St. Clair Shores Drain site consists of soils in an underground storm utility corridor, near the intersection of Bon 

Brae Street and Harper Avenue, in St. Clair Shores, Michigan, heavily contaminated with polychlorinated biphenyls 

(PCBs). St. Clair Shores is located northeast of the City of Detroit and along the western shore of Lake St. Clair. 

PCBs have also migrated and contaminated sediments throughout the 10 Mile Drain storm sewer system, and are 

present in canals where the storm sewer currently and historically discharged, and in Lake St. Clair. 

 Site History: 

The site was discovered in 2001 when the Macomb County Drainage Commission collected sediment samples as part 

of a proposed dredging project. The Michigan Department of Environmental Quality (MDEQ) was contacted because 

elevated levels of PCBs were found during sediment sampling. Additional investigations by MDEQ and EPA located 

highly contaminated soils near Bon Brae Street. The original source that contaminated soils and sediments in the 

utility corridor is unknown. 

 Site Contamination/Contaminants: 

The heavily contaminated soils in the utility corridor are found in an area of approximately two city blocks. PCB 

contamination has migrated to the 10 Mile Drain storm sewer, which covers an area of approximately 258 acres. 

PCBs have been found in four canals that are connected to Lake St. Clair where the sewer currently and historically 

discharged, and in Lake St. Clair. In total, these canals comprise approximately 1.4 miles. 

 Potential Impacts on Surrounding Community/Environment: 

Potential impacts include health risks from potential exposure to PCBs in the surface water and sediments of the 

canals and lake, exposure to PCBs through consumption of fish caught in the canals and lake, and potential soil 

exposure to PCBs in the area of the historical discharge. 

 Response Activities (to date): 

At the request of the MDEQ, EPA performed a sediment removal action in two of the canals in 2002. However, 

sediments in these canals have been re-contaminated. In 2006, as an interim action, EPA also cleaned and installed a 

liner in a portion of the storm sewer where the heavily contaminated source soils are located. 

 Need for NPL Listing: 

The State of Michigan referred the site to EPA in order to fully characterize the nature and extent of PCBs at the site. 

Other federal and state programs have been evaluated, but are not viable at this time. EPA received a letter of support 

for placing this site on the NPL from the state. 

[The description of the site (release) is based on information available at the time the site was evaluated with the HRS. The description may change 

as additional information is gathered on the sources and extent of contamination.] 

For more information about the hazardous substances identified in this narrative summary, including general information regarding the effects of exposure to these 

substances on human health, please see the Agency for Toxic Substances and Disease Registry (ATSDR) ToxFAQs. ATSDR ToxFAQs can be found on the Internet 

at http://www.atsdr.cdc.gov/toxfaq.html or by telephone at 1-888-42-ATSDR or 1-888-422-8737.