PCB Hotspots
in Estabrook Impoundment
Peter Gill, Milwaukee
Riverkeeper
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 FMR'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
Read the DNR study of Estabrook Impoundment in its entirety.
Sources:
More information on PCBs from
Midwest Center for Environmental Science and Public Policy
http://www.mcespp.org/pcbs.html
PCB Background:
Fish Consumption:
http://www.dnr.state.wi.us/org/water/fhp/fish/pages/consumption/
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