Tests recently conducted by the Michigan Department of Environmental Quality have determined that Conner Creek on the city’s east side is one of the Detroit River’s most polluted sites.
"Sediments were found to be extremely contaminated," stated a report issued by the DEQ. "Heavy metals such as cadmium, chromium and lead were found at the highest levels measured in recent surveys of the Detroit and Rouge Rivers."
Of particular concern were the levels of PCBs, or polychlorinated biphenyls, a highly toxic material formerly used to insulate large electrical transformers and capacitors. Their production and sale was banned in the 1970s, but because they do not break down PCBs continue to be a persistent environmental problem, especially in industrial areas such as Detroit.
Samples taken at three sites in 1997 and 1998 found PCB levels at the top layers of sediment that were 15 to 30 times higher than amounts considered to be toxic to aquatic life, according to the report. Samples from deeper layers of sediment found PCB present in amounts that are more than 60 times the level considered to be toxic to aquatic life.
A tributary to the Detroit River, Conner Creek is used as a drainage canal to carry storm water and sewage overflow during periods of heavy rain.
Also of concern were levels of lead and arsenic, which "exceeded residential contact standards," according to the report.
"Extremely high" levels of oil and grease, in some cases found to be at 7.4 million parts per billion, were also found.
"It’s hard to even call it sediment," says Art Ostaszewski, a DEQ aquatic biologist who authored the report. "It’s more like a sludge."
"With the highest levels of contamination, the large size of the depositional zone and proximity at the head of the Detroit River," states the report, "Conner Creek likely harbors the largest contiguous mass of contaminants in an aquatic environment in the Detroit River and is likely a source of contamination to areas downstream."
In other words, the site is a prime candidate for cleanup.
"If you are looking for a place to start remediation of the river, it’s best to start upstream, so that you are near the head of the river," says Dave Dolan, a research scientist for the International Joint Commission, which monitors cleanup efforts of waters bordering the United States and Canada.
Primary responsibility for cleaning up Conner Creek belongs to the city of Detroit, says Ostaszewski. But a cooperative effort among state and federal environmental agencies, the city, industries in the area and local residents will be required to accomplish clean-up.
"What we don’t want is for this to get bogged down in finger-pointing and tied up in court," says Ostaszewski. "This needs to be a partnership."
Other agencies involve the state’s Department of Community Health, which is studying whether to fence off access to the creek to protect area residents, says Ostaszewski.
Further study will be required to determine the full scope of contamination. A new round of extensive sampling will begin this spring, according to Ostaszewski.
A final plan for dredging the contaminated sediment and how it will be treated or disposed of has not yet been determined.
A community meeting on the issue will be held at 6 p.m. Monday, March 8, at the Remus Robinson Middle School, 1300 Essex St. For more information, phone 313-822-6118, ext. 2.
