Project Overview
The City of Los Angeles is committed to a sustainable water future that relies more on local water supplies than costly and unreliable imported water. The plan to increase local water resources includes groundwater replenishment using advanced purified water. The Los Angeles Department of Water and Power (LADWP), in partnership with the Los Angeles Bureau of Sanitation (LASAN), is undertaking the Los Angeles Groundwater Replenishment Project (LAGWR). LAGWR will provide up to 22,000 acre-feet per year (AFY) of purified water to replenish the San Fernando Groundwater Basin using proven, state-of-the-art technology that is highly protective of human health. LAGWR is an important investment in developing a local, drought resilient, and reliable water supply for a sustainable Los Angeles.
LAGWR includes the construction of an Advanced Water Purification Facility (AWPF) at the Donald C. Tillman Water Reclamation Plant (Tillman). This new facility adds advanced treatment – that meets the highest regulatory standards – to the existing, multistep treatment process at Tillman. Up to 22,000 acre-feet per year of purified water will be delivered through an existing pipeline to the Hansen Spreading Grounds (HSG). Following spreading at HSG, the purified water will infiltrate into the San Fernando Groundwater Basin where it will remain for several years, adding to L.A.’s future drinking water supply.
Multiple Levels of Treatment
At Tillman, operated by LASAN, wastewater from homes and businesses undergoes multiple levels of treatment to produce recycled water. Recycled water is currently used for irrigation, commercial, industrial, and environmental uses. LAGWR’s AWPF will add full advanced treatment as part of the multistep process to purify recycled water for groundwater replenishment. The advanced treatment process includes membrane filtration, reverse osmosis, and ultraviolet advanced oxidation. This process exceeds the regulatory requirements for surface spreading.
The purified water will then be conveyed through an existing recycled water pipeline to the Hansen Spreading Grounds. The existing recycled water pipeline will be pretreated to prepare it for receipt of the new, purified water from AWPF. The water will be added to the spreading grounds where it will flow through the soil to replenish the aquifer in the San Fernando Groundwater Basin.
The water will travel underground for several years until it is pumped out by existing groundwater wells and further treated with existing drinking water treatment to supplement the City’s drinking water supplies.
Project Timeline
- Summer 2024: 100% Design completion
- Winter 2024: Construction begins
- Winter 2027: Construction ends
- Summer 2028: LAGWR online and operational