Under the National Pollutant Discharge Elimination System (NPDES) permits issued to the City and County of San Francisco (City) to operate the Southeast and Oceanside Water Pollution Control Plants, the City is required to implement a Pretreatment Program. This Program is required to comply with the regulations incorporated in the Clean Water Act (33 United States Code [U.S.C] section 1251 et seq.) and the General Pretreatment Regulations (Title 40 of the Code of Federal Regulations [CFR] Part 403).
SFPUC enforces the Pretreatment Program by regulating discharges from non-domestic sources into the City's sewerage system. Regulations governing these discharges are contained in the City's sewer use ordinance - Article 4.1, Chapter X, Part II of the San Francisco Municipal Code. Additional wastewater pollutant limitations are contained in the City's Department of Public Works Order No. 158170.
What is Pretreatment?
Wastewater from non-domestic (i.e., industrial and commercial) sources can contain pollutants, such as fats, oils and grease, heavy metals (such as lead and mercury) or low pH. These pollutants can damage sewers, interfere with the operation of treatment plants, pass through the treatment plants into the receiving waters or into the sludge removed at the plants, or jeopardize the health and safety of sewerage system personnel, as well as the general public. The practice of removing pollutants from industrial and commercial wastewaters before they are discharged into municipal sewage treatment systems is known as "pretreatment." Pretreatment differs from pollution prevention, which focuses on procedures to reduce or eliminate the introduction of pollutants into wastewaters from residential, commercial and industrial sources.
Wastewater Discharge Permits
In San Francisco, SFPUC issues Industrial User Permits to “industrial users” for regular or continuous discharges that result from commercial or industrial operations, such as:
- Food Processors
- Dental Offices
SFPUC also issues Batch Wastewater Discharge permits for non-routine, episodic, or other temporary discharges, such as:
- De-watering of construction sites
- De-watering of wells drilled to investigate or mitigate a suspected contaminated site
- Power-washing of buildings or parking lots
- Any other activity that generates wastewater, other than from routine commercial or industrial processes
The permits specify the conditions under which wastewater may be discharged into the sewer system. Permits are issued for a specified duration and are tailored to each user.