A Significant Industrial User (SIU) is defined by the US Environmental Protection Agency (EPA) as an industrial user that discharges process wastewater into a publicly owned treatment works (POTW) and meets at least one of the following:
- All industrial users subject to Categorical Pretreatment Standards under the Code of Federal Regulations -- Title 40 (40 CFR) Part 403.6, and CFR Title 40 Chapter I, Subchapter N - Effluent Guidelines and Standards and
- Any other industrial user that:
- discharges an average of 25,000 gallons per day or more of process wastewater to the POTW (excluding sanitary, non-contact cooling and boiler blowdown wastewater) or
- contributes a process wastestream which makes up 5 percent or more of any design capacity of the POTW treatment plant or
- is designated as such by the City of Greensboro Industrial Waste Section on the basis that the industrial user has a reasonable potential for adversely affecting the POTW's operation or for violating any pretreatment standard or requirement.
Useful Links for Determining if an SIU Permit is Needed:
SIU Permit Application -- This document is provided for informational purposes only. Please contact Industrial Pretreatment staff to get instructions before completing the form.