Wis. Stat. § 77.9962

There is imposed on each person who sells a dry cleaning product to a dry cleaning facility a fee equal to $5 per gallon of perchloroethylene sold and 75 cents per gallon of any dry cleaning product sold, other than perchloroethylene. The fees for the previous 3 months are due on January 25, April 25, July 25, and October 25.