The Michigan Department of Community Health says it's not dangerous to drink water from wells along the Kalamazoo River, which was polluted by a 2010 oil spill.
The department said Monday it analyzed samples from 150 wells in Calhoun and Kalamazoo counties after a ruptured pipeline sent more than 800,000 gallons of crude into the river.
It says just two oil-related chemicals were found in the samples - iron and nickel. But they occur naturally and were present even before the spill.
Spokeswoman Angela Minicuci says it's uncertain whether the chemicals came from the oil. But she says levels are too low to harm health.
Some wells have arsenic and lead, but the spilled oil didn't contain those elements.
The Enbridge Inc. pipeline runs from Indiana to Sarnia, Ontario.