The city of Ann Arbor has detected very low levels (0.039 parts per billion) of 1,4 dioxane in its drinking water for the second time.
Similar levels (0.030) were found about one year ago.
The city tests its drinking water monthly.
According to city officials, the curent detectable levels in the city's drinking water are not considered a health risk.
"They're very, very low," said Brian Steglitz, Ann Arbor's water treatment services manager. "And well below, over ten times lower than the EPA identified risk level."