NPL Site Narrative for Ten-Mile Drain
St. Clair Shores, Michigan
The Ten-Mile Drain site consists of the concrete sewer pipes which compose the Ten-Mile Drain storm sewer system, and soils which surround the storm sewer pipes in an underground storm utility corridor, located near the intersection of Bon Brae Street and Harper Avenue, in St. Clair Shores, Michigan. The storm sewer pipes are 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 migrated and contaminated sediments throughout the Ten-Mile Drain, and are present in canals where the storm sewer currently and historically discharged, and in Lake St. Clair.
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.
The heavily contaminated soils in the utility corridor are found in an area of approximately two city blocks. PCB contamination has migrated to the Ten-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 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. See 56 FR 5600, February 11, 1991, or subsequent FR notices.]
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 ATSDR - ToxFAQs (http://www.atsdr.cdc.gov/toxfaqs/index.asp) or by telephone at 1-888-42-ATSDR or 1-888-422-8737.