Toxic PCB levels are higher than ever in a drain and several canals in the St. Clair Shores area, despite a $10 million cleanup.
PCBs are chemicals found to cause numerous illnesses, including cancer. The federal government banned their use in the 1970s.
They were discovered in 2001 in the Ten Mile drain and Lange-Revere canals.
The cleanup reduced PCB levels in the water to 10 parts per million, which the Environmental Protection Agency called safe. But tests have detected levels of up to 820,000 parts per million.
Local officials the site added to the federal Superfund cleanup list.