PCB Hotspots in Estabrook Impoundment
By Peter Gill, Milwaukee Riverkeeper - 2006
A study released by the Department of Natural Resources (DNR) in August 2005 identified PCB contamination hotspots in the Estabrook Impoundment on the Glendale-Milwaukee border. The study found that the impoundment has significant toxic-level contamination. FMR's hotspot map has pinpointed areas of greatest concern. Additionally, the study found that levels of other contaminants (metals, PAHs and other organics) are elevated, but not beyond other urban waterways. Lastly, the study recognized the impoundment as a strong source of PCB contamination to the Milwaukee River downstream.
What are PCBs?
Polychlorinated biphenyls (PCBs) are a group of 209 related carbon-based chemicals. These man-made oily chemicals are fat-soluble and can accumulate in the fatty tissues of animals exposed to PCBs in the environment. PCBs were historically used as heat resistive insulators in electrical products, but the market for their use grew rapidly. The very persistent nature of these toxins diversified their uses from industrial to household use. PCB production in the US was banned in 1979 due to environmental and human health concerns, although equipment in use at the time of the ban has remained. For more background information about PCBs see the Environmental Protection Agency’s fact page.
Where are the PCBs?
The focus of the study was the Estabrook Impoundment located between the City of Glendale and the City of Milwaukee. The project studied the rivers and its banks from Lincoln Creek downstream from Green Bay Road to the Estabrook Park Dam on the Milwaukee River. (See the study area map and the identified hotspots.) Areas within the western oxbow, the Blatz Pavilion, and Milwaukee River channel were identified as the crucial hotspots. These areas contained sediments with at least 400 parts per million (ppm).
Health Concerns
Despite a PCB production ban in the United States, PCBs are continually affecting our waterways and our health. This study found concentrations ranging from 1 ppm to 870 ppm in the Milwaukee River sediments. For comparison, the Environmental Protection Agency (EPA) allows a maximum contaminant of 0.0005 ppm in drinking water.
What harm?
These toxic chemicals have been proven to cause liver, neural, skin, reproductive and immune system problems in laboratory animals. Human health concerns due to PCB exposure can be divided into long-term and short-term effects. Short-term exposure can result in hearing and vision problems, acne-like eruptions, and skin pigmentation. Long-term exposure has the potential for changes in liver function, and gastrointestinal, immune, and reproductive system problems. Damage to neural development in human fetuses is documented. The EPA lists PCBs as “probably human carcinogens.”
How?
Transmission occurs through direct exposure with contaminated waters and sediments, consumption of contaminated animals, and inhalation of PCB vapor. Aquatic animals living in contaminated river ways can accumulate PCBs in their fatty tissues. In turn, people absorb these toxins from the foods they eat. Of particular concern is the ease of transmission of contaminants from pregnant and nursing mothers to their children. Depending on the type of PCB they can take from 1 to 8 years to degrade in the human body.
What does this mean for me?
Residents and users of the Estabrook Impoundment need to take caution when using the waterway. Consumption and preparation of fish should follow the DNR’s advisories. Also, swimming is not recommended for people or their pets. Boating restrictions have not been determined. However, after contact with water or sediments, it is advised to wash well. A test to determine the level of PCB contamination in humans is available, although no test can determine the possible result to your personal health.
What can be done?
The report emphasizes PCB contamination management through public awareness, advisories, and access restrictions. The report outlines possible remediation actions, but refrains from giving specific recommendations. Treatment options include: removal of hotspots, sediment containment, and allowing natural release of PCBs in areas of relatively low contamination. The final solution will undoubtedly be a combination of these tactics. Projected costs range from $18-36 million depending on the management practices employed, the amount of area treated, and the degree of treatment.
Several clean-up tools were not mentioned in this DNR study, but have been used at other contamination sites throughout the country. An interesting technique called bioremediation employs carbon-consuming bacteria to digest contaminates within river sediments. The result is an environmentally friendly byproduct. Currently there are 20 strains of bacteria that use biphenyl as their only source of carbon. Also, if the sediments can be removed from the location and placed in an incinerator, heating to 2,400º F can destroy PCBs. All solutions will involve weighing costs, benefits, and effectiveness.
Note: This document is Riverkeeper's review of the DNR report entitled:
Estabrook Impoundment Sediment Remediation Pre-design Study Project Completion Report to USEPA GLNPO Grant ID 2000-082 Wisconsin Department of Natural Resources Publ-WT 826 August 2005
Sources:
More information on PCBs from Midwest Center for Environmental Science and Public Policy
http://www.mcespp.org/pcbs.html
PCB Background:
http://www.epa.gov/ost/fish/pcbs.pdf
Fish Consumption:
http://www.dnr.state.wi.us/org/water/fhp/fish/pages/consumption/
