Treatment Plant

The San Jose/Santa Clara Water Pollution Control Plant (Plant) is one of the nation's largest and most advanced wastewater treatment facilities. The Plant serves more than 1.4 million residents and businesses in the eight tributary cities:

• San José
• Santa Clara
• Milpitas
• Campbell
• Cupertino
• Los Gatos
• Saratoga
• Monte Sereno

The cities of San José and Santa Clara co-own the Plant. Six other cities have contracts with the Plant, either directly or through sanitation districts. The Plant is located in Alviso and managed and operated by the City of San José Environmental Services Department.

The Plant was constructed in 1956 with a capacity to treat up to 167 million gallons of wastewater per day. Water that drains from sinks, showers, toilets, washing machines, and floor drains from homes and businesses contributes 110 million gallons of wastewater daily.

Wastewater System
After the water leaves homes and businesses, it enters an intricate wastewater pipe system that funnels into increasingly large pipes that lead to the Plant.

The water undergoes a sophisticated, 18-hour treatment process that simulates natural water purification. By the time the wastewater is discharged into the Bay, 99 percent of water impurities have been removed.

Other wastewater system components include the sanitary sewer system and the Plant biosolids area.

Water Recycling
Most of the wastewater that enters the sewer system is cleaned at the Plant before discharged as fresh water through the Artesian Slough and into South San Francisco Bay.

About 10 percent of the wastewater is treated further and recycled through South Bay Water Recycling pipelines. The recycled water is used for landscaping irrigation, industrial processes, and cooling at regional businesses and facilities.

Stormwater System
The Plant does not collect or treat stormwater. A separate stormwater system collects all outdoor water, including rain and runoff, and discharges into local rivers and creeks without treatment.