The Sanitation Districts have a proud tradition of providing low-cost, high-quality wastewater treatment for Los Angeles County. This includes operating one of the largest, engineered wastewater recycling programs in the world.
Water recycling is very important in our arid Southern California environment where water must be imported from other parts of the state. The goal of the Sanitation Districts is to recycle as much water as possible from its Water Reclamation Plants (WRPs), therefore, the WRPs play a major role in meeting our water needs. This recycling significantly reduces the Los Angeles Basin's dependence on costly imported water and helps to replenish a large percentage of the groundwater used by the region.
The WRPs literally replicate what happens in nature. They just speed up the process and do it in modern, water treatment chemicals high-tech facilities. They provide what is known as primary, secondary, and tertiary treatment for approximately 165 million gallons of wastewater per day. The following describes the wastewater treatment and water reclamation processes.
A treatment plant is just like a natural river but in a concrete box. First, materials settle to the bottom of the primary settling tanks (Primary Treatment). Second, microbes use air to breath while they eat up organic material in the aeration tanks, then the microbes settle out in the secondary settling tanks (Secondary Treatment). Third, sand and coal filter out leftover particles in the filters (Tertiary Treatment) like sand in the bottom of a river.