Testing conducted over the weekend by the Michigan Department of Environment, Great Lakes, and Energy (EGLE) did not detect the presence of hexavalent chromium in the Huron River system downstream of a chemical release.
On Saturday, EGLE crews tested 55 locations throughout the river system from Barton Pond -- where the city of Ann Arbor has a drinking water intake -- upstream to Wixom. None of the 75 samples tested from those locations had detectable level of either hexavalent chromium or total chromium.
Industrial chemicals were discharged to the sanitary sewer system from Tribar Manufacturing in Wixom the weekend of July 30 and routed to the Wixom wastewater treatment facility. The wastewater discharges to Norton Creek, which flows into the Huron River system. The liquid contained hexavalent chromium, a known carcinogen that can cause a number of adverse health effects through ingestion, skin contact or inhalation.
Of 144 water samples collected throughout 42 river miles since the release, three came back with detections of hexavalent chromium -- two detections in Milford's Hubbell Pond and one in the middle of Kent Lake. The Kent Lake detection, completed by lab analysis late Friday -- was 5 parts per billion (ppb) -- just at the detectable limit of 5 ppb. The two Hubbell Pond detections were 11 and 9 parts per billion. All three were at or below values to protect aquatic life.*
Investigators are evaluating test results from wastewater solids that were sequestered at the Wixom Wastewater treatment plant that appear to have trapped chromium, including hexavalent chromium, and of a carbon filtration system at Tribar that may have trapped the hexavalent chromium before it was discharged to the wastewater plant.
Until further notice, the Michigan Department of Health and Human Services (MDHHS) is recommending that people and pets 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).
As additional test results are received, MDHHS will update this recommendation.
For the section of the Huron River described above:
- Don't swim in, wade in, play in or drink water directly from the Huron River.
- Don't water your plants or lawn with Huron River water.
- Don't eat fish caught in this section of the Huron River. A do not eat advisory for PFOS is already in effect.
Officials stressed that properly constructed and permitted drinking water wells should not be directly influenced by surface water, and therefore, are unlikely to be contaminated by any chromium in the river. Hexavalent chromium from this release is unlikely to enter the groundwater. Unpermitted driven sand points and submerged irrigation pumps installed by property owners along the river may be vulnerable and should never be used for drinking water.
EGLE staff continues the investigation to determine why the release occurred, the exact volume and product that was released, and the timeline of events.
State and local officials continue to work together to protect public health, keep residents informed, and answer questions. Some resources for the public include:
- Webpages from the Oakland and Washtenaw county health departments, and the City of Ann Arbor.
- MDHHS' MI Toxic Hotline for questions about potential health effects or exposures. 800-648-6942, 8 a.m. to 5 p.m., Monday through Friday.
- EGLE's Environmental Assistance Center, a single point of entry into the agency's programs: EGLE-Assist@Michigan.gov or 800-662-9278.
Categories: Michigan, Energy, General