New & Non-Permitted Users
General Pretreatment Regulations require a wastewater treatment plant (WWTP) to identify and locate all possible Industrial Users (IU) which might be subject to the Industrial Pretreatment Program, to identify the character and volume of pollutants contributed to the WWTP, and to notify IU of applicable Pretreatment Standards and other applicable regulatory requirements. The industrial waste survey is designed to identify businesses that discharge wastewater containing nondomestic pollutants that must abide by general and specific prohibitions (Chapter 11.1-03) and follow industry-specific Best Management Practices (BMPs). BMPs can prevent the release of pollutants that can damage the sewers or the treatment plant, cause the plant to release pollutants that violate its Permit, or endanger wastewater personnel. For example, restaurants that do not properly maintain their grease interceptors can cause grease clogs in the sewer resulting in sewer backups into streets or basements; auto repair shops that do not properly dispose of used solvents can cause an explosion hazard in the sewer or at the plant headworks; and car wash operations that use acidic cleaners and do not properly neutralize their wastewater prior to discharge can cause acid damage to the sewers.
Significant Industrial Users
Industrial users may be subject to regulation for a number of reasons. They may meet the definition of a Significant Industrial User (SIU) for any of the following:
- A user subject to national categorical pretreatment standards as defined by the U.S. Environmental Protection Agency. These processes by their nature generate pollutants that, if unregulated, can disrupt treatment processes, pass through the plant unchanged and pollute the river, or create hazardous conditions in the sewer or treatment plant.
- A user that:
- Discharges an average of 25,000 gallons per day or more of process wastewater to the sewer; or
- Contributes a process waste stream which makes up 5 percent or more of the average dry weather hydraulic or organic capacity of our treatment plant. “Organic capacity” means the capacity of the treatment plant to treat wastewater as opposed to the “hydraulic capacity” or capability to accept and handle fluids; or
- Designated by the City, State or EPA as having a reasonable potential to adversely affect the City’s wastewater collection or treatment system or to violate any pretreatment standard or requirement.
The City of Bismarck requires all SIU to obtain a Wastewater Discharge Permit. Pretreatment program staff inspect such permitted businesses, sample their wastewater discharges, and work with them to protect the environment, the wastewater treatment plant, and personnel.