At least four Detroit-area municipalities are facing class actions alleging that their sewer or water fees are actually unconstitutional under state law.

In the coming weeks, all 26,000 Waterford Township water and sewer account holders will receive notice that they may apply for refunds for sewer fees between 2010 and this year, as part of a settlement reached between the township and a citizen alleging water and sewer charges were actually improper taxes. The $1.4 million settlement in Mason...