Significant Industrial User (SIU) Permit Information

A Significant Industrial User 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:

  1. 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
  2. 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:

 Revised 12/2/08! Sewer Use and Pretreatment Ordinance (pdf)

State of North Carolina Pretreatment, Emergency Response, and Collection Systems Unit (PERCS) - Pretreatment Requirements / Information

EPA Effluent Guidelines

EPA: Federal Register Environmental Documents

Code of Federal Regulations (CFR), e-CFR

SIU Permit Application (pdf) - This document is provided for informational purposes only. Please contact Industrial Pretreatment staff to get instructions before completing the form.