Michigan state investigators said test samples taken Thursday from Hubbell Pond in Milford showed low-level presence of a toxic chemical that was released into the Huron River System by the Tribar Manufacturing company in Wixom last weekend.
Two crews from the Michigan Department of Environment, Great Lakes, and Energy sampled waters upstream, downstream and within the pond on Friday to gather more information on the presence of hexavalent chromium, a known cancer-causing chemical.
According to Michigan authorities, hexavalent chromium is known carcinogen that can cause a number of adverse health effects through ingestion, skin contact or inhalation.
State officials are still investigating why the release occurred, the exact volume and product that was released and the timeline of events.
The Hubbell Pond samples were the only ones where hexavalent chromium was detected, out of the more than 30 samples that were taken from varying depths from near the point of release downstream to Barton Pond in Ann Arbor.
"Liquid containing 5% hexavalent chromium was discharged to the sanitary sewer system from Tribar Manufacturing in Wixom last weekend and routed to the Wixom wastewater treatment facility," Michigan Department of Environment, Great Lakes, and Energy said in a statement.
Michigan authorities advised people and pets to avoid contact with the Huron River water between North Wixom Road in Oakland County and Kensington Road in Livingston County. This includes Norton Creek downstream of the Wixom Wastewater Treatment Plant (Oakland County), Hubbell Pond (also known as Mill Pond in Oakland County) and Kent Lake (Oakland and Livingston counties).
Residents are also warned not to water their plants with river water or eat fish caught in that section of the river.
Authorities also warned this recommendation could be expanded to other areas of the river as it receives additional test results.
Properly constructed and permitted drinking water wells not influenced by surface water are unlikely to be contaminated by chromium from the river, they said.