The City of Los Angeles Bureau of Sanitation operates four treatment plants in the City of Los Angeles—Hyperion Treatment Plant, Donald C. Tillman Water Reclamation Plant, Los Angeles-Glendale Water Reclamation Plant, and the Terminal Island Water Reclamation Plant.
The water treatment process is similar, however treatment levels vary from plant to plant.
- PRELIMINARY TREATMENT: This takes place as the sewage comes into the plant where the course debris and grit is removed through bars and rakes.
- PRIMARY TREATMENT: 70% of organic and inorganic is removed from the raw wastewater. Solids are allowed to settle and oils and grease rise to the top. Both are collected and returned to the sewer.
- SECONDARY TREATMENT: Biological treatment occurs here—living organisms are added to feed on the bio-solids. Aeration also occurs, helping the organisms to thrive. The fat organisms then settle to the bottom and are removed to be used again.
- TERTIARY TREATMENT: Water passes through sand filters where the remaining solids are removed. From there it is disinfected and ready for use.
- MICROFILTRATION and REVERSE OSMOSIS: At this time, the Terminal Island Water Reclamation Plant is the only plant in the city to produce advanced treated water.
