Treatment Process


The San Mateo facility serves more than 130,000 people and businesses in our service area at an average flow of 12 million gallons each day. By effectively treating wastewater at an advanced biological treatment facility, the plant helps keep San Francisco Bay environmentally clean and safe.

The treatment plant uses bacteria to remove organic material and toxins from the wastewater it treats. Sewage arrives at the plant through a series of pipelines and pump stations. The sewage then passes through a series of physical and biological processes which result in high-quality effluent being discharged to the deep-water channel of the Bay.

View the plant schematic of treating wastewater.