Industrial Wastewater Pretreatment Program

The Pretreatment Program administers local, state and federal regulations affecting area businesses and the quality of the wastewater discharged into the City of Winston-Salem's wastewater treatment system. These regulations were implemented:

  • To prevent the introduction of pollutants into the municipal wastewater system which will interfere with the operation of the system or contaminate the resulting sludge
  • To prevent the introduction of pollutants into the municipal wastewater system which will pass through the wastewater system, inadequately treated, into any waters of the state or otherwise be incompatible with the system
  • To promote reuse and recycling of wastewater and sludge from the municipal system
  • To protect both municipal personnel who may be affected by sewage, sludge, and effluent in the course of their employment as well as protecting the general public
  • To provide for equitable distribution of the cost of construction, operation, maintenance and improvement of the municipal wastewater system
  • To ensure that the municipality complies with its National Pollutant Discharge Elimination System (NPDES) permit conditions, sludge use and disposal requirements and any other federal or state laws to which the municipal wastewater system is subject

Area businesses are required to install, operate and adequately maintain pretreatment equipment and/or systems to remove those pollutants that could otherwise damage or obstruct the wastewater collection system; or interfere with or pass through the wastewater treatment process. Examples of such pollutants include heavy metals, cyanide, toxic organics, and acidic or caustic wastes from industrial operations. The wastewater from restaurants and other food service industries are often more problematic due to conventional pollutants such as grease and solids.

Major Elements

Some major elements of the city's Pretreatment Program include: 

  • The collection of samples
  • The initiation of enforcement activities when appropriate
  • The issuance of permits
  • The performance of inspections
  • The review of permittee self-monitoring reports
  • The review of pretreatment designs

Sample Manhole

The City of Winston-Salem Pretreatment Program inspects and monitors industrial and commercial wastewater sources discharging to the City's wastewater collection system to verify compliance with all applicable pretreatment standards. Any facility whose wastewater service line is not already connected at a wastewater manhole would be required to have a control manhole if:

  • The facility is or will be discharging wastewater regulated under the Sewer Use Resolution (PDF)
  • The city can show through documented historical data or information that problems exist at the part of the collection system to be used by the facility. These problems can include: 
    • Backups
    • Corrosion
    • High grease or solids
    • Line stoppages
    • Overflows
    • Etc. 

Control manholes shall be located on the facilities premises and be constructed in the right of way without obstruction by landscaping or parked vehicles. See the Water and Sewer Technical Specifications under the Forms and Application Section.