This 1989 law prohibited the use of once-through water systems in the Twin Cities after 2010, and immediately raised the price of using once-through water 200-fold for commercial users and 50-fold for non-profits and schools. The Act, administered by the Division of Waters of the Department of Natural Resources, requires that a conversion plan be submitted by users by Jan 1992. The once-through systems must be converted within the design life of the equipment based on the ASHRAE service life for primary system components. This ranges between 19-24 years, with 1990 used as the base year to determine the remaining service life for a system. Once-through water for heating and cooling systems for commercial users is $200 per million gallons with no maximum fee. The fee for non-profits and school districts is 5 cents per 1000 gallons until 1993 ($50 million per million gallons), rising to 10 cents in 1993 and to 15 cents in 1997 ($150 per million gallons). The current fee for water not appropriated for once through systems or for other uses is $50 for up to 50 million gallons, or $1 per million gallons and rises to a maximum of $4.50 per million for use above 400 million gallons, according to the Division of Waters.