Industrial Pretreatment

The Industrial Pretreatment Program is a component of the NPDES/OPDES Program. The term “pretreatment” means the treatment of wastewater by commercial and industrial facilities to remove harmful pollutants before being discharged to a sewer system under the control of a publicly owned treatment works (POTWs). ). “Pretreatment” is also defined in Title 40 Code of Federal Regulations (40 CFR) Subsection 403.

Wastewater from homes, commercial buildings, and industrial facilities is collected and transported through a series of pipes—that is, a collection system—to wastewater treatment plants (WWTPs). These WWTPs remove harmful organisms and contaminants from the wastewater before discharge into the receiving creek, river, or lake.

Most POTWs are designed to treat sanitary (domestic) wastes from households, but not to treat toxic pollutants from industrial or commercial facilities. The toxic pollutants from industrial and commercial facilities may cause serious problems at POTWs. These problems may be prevented by recycling, waste minimization, chemical substitution, pretreatment, or other best management practices to reduce or eliminate the pollutants from commercial or industrial facilities.

The U.S. Environmental Protection Agency (EPA) developed the General Pretreatment Regulations under 40 CFR Part 403 to set responsibilities for federal, state, and local government, industry, and the public to achieve the National Pretreatment Program objectives. The EPA describes this national program in its “Introduction to the National Pretreatment Program.”

The program is designed to:

  • prevent interference with the operation of your wastewater treatment plant
  • prevent the introduction of pollutants that could pass through your wastewater treatment plant untreated and into the receiving body of water
  • improve opportunities for reuse or recycling of wastewater and sewage sludge
  • prevent the introduction of pollutants that could cause health or safety problems to the public or the environment

In Oklahoma, industries are regulated by the DEQ Industrial Pretreatment Program in one of two ways:

  • Regulated directly by the Municipality through a State-approved Pretreatment Program
  • Regulated by the DEQ through an Indirect Discharge Permit if the Municipality does not have a State-approved Pretreatment Program or is not required to develop one.

For more information, please contact Gabriel Stevens at