Processes industrial and commercial business use to treat by reducing, eliminating, or altering the nature of wastewater pollutants before (pre) they are discharged into the City sewer system.

The Pretreatment Program makes every effort to maintain working partnerships with the City's regulated industries, valuing information and compliance over enforcement as the best way to achieve mutually beneficial economic and environmental goals. However, if an industry remains non-compliant, that industry will be subject to enforcement action.

No. The City may regulate individual or specific businesses based on the wastewater they discharge. Significant Industrial Users (SIUs) are always regulated and are issued a discharge permit that has specific discharge, monitoring, and reporting requirements.

The term Significant Industrial User as defined by the EPA means:

1. All industrial users subject to Categorical Pretreatment Standards under 40 CFR 403.6 and 40 CFR chapter I, subchapter N;
2. Any other industrial user that
   1. discharges an average of 25,000 gallons per day or more of process wastewater;
   2. contributes a process waste stream which makes up 5 percent or more of the average dry weather hydraulic or organic capacity of the treatment plant; or
   3. is designated as a SIU by the City on the basis that the industrial user has a reasonable potential for adversely affecting the operation of the City's wastewater treatment plant.

Any non-residential user that discharges non-domestic wastewater to the City of Louisville’s sanitary sewer system.