National categorical pretreatment standards as promulgated by the U.S. EPA pursuant to the Act shall be met by all dischargers of the regulated industrial categories.
POTW may determine Equivalent Mass and Concentration Limits using categorical pretreatment standards and the average daily production and flow. Industrial users must promptly notify the POTW of expected production changes. Equivalent Mass and Concentration Limits are made legally enforceable where they are established; they are deemed pretreatment standards which industrial users will be required to comply with in lieu of the promulgated standards.
Categorical Pretreatment Standards may be adjusted to reflect the presence of pollutants in the industrial user's intake water. Applications for intake pollutant credit must be made to the POTW instead of the U.S. EPA. The POTW may also waive the "same body of water" requirement if it finds that no environmental degradation will result.