Industrial Pretreatment

Pretreatment Standards
The National Pretreatment Program began after the passage of the Clean Water Act of 1972. The act called for the Environmental Protection Agency (EPA) to develop national pretreatment standards to control industrial discharges into the sewer system.

Definition of Pretreatment
Pretreatment is the application of physical, chemical, or biological cleanup methods to industrial or non-domestic wastewater before it is discharged to a stream or to the publicly owned treatment works (POTW). The purpose of pretreatment is to protect the treatment plant processes and personnel, health of the general public, and the receiving stream's water quality standards.

Significant Industrial Users
The Water Pollution Control Plant (WPCP) administers the pretreatment program. The pretreatment program regulates all significant industrial users (SIU) that discharge process water to the wastewater collection system.

The Code of Federal Regulations 40 CFR 403.3 defines SIUs as the following:
  • Any industrial user who is subject to categorical pretreatment standards
  • Any other user that has any 1 or more of the following characteristics:
    • Has an average discharge flow equal to or greater than 25,000 gallons per day of process wastewater to the WPCP
    • Contributes a process waste stream which is 5 percent or more of the average dry weather hydraulic or organic capacity of the WPCP
    • Is determined by the plant director have a reasonable potential to adversely affect the WPCP operation
    • Violates any pretreatment standard or requirement (in accordance with 40 CFR403.8 (f) (6))
    • Has a discharge that is either domestic in nature, or has no discharge at all, but the facility does have significant quantities of pollutants that, if discharged, would be regulated
Requirement for New Businesses
New businesses are required to fill out an Industrial User Survey.