Los Angeles Sanitation and the Los Angeles Department of Water and Power are committed to a sustainable water future that relies more on local water supplies than costly and unreliable purchased imported water. The plan to increase local water resources includes groundwater replenishment using purified recycled water (purified water). The Los Angeles Groundwater Replenishment (GWR) Project is an important infrastructure investment that will help develop a local, safe and reliable water supply for a sustainable Los Angeles.
The Los Angeles Groundwater Replenishment (GWR) Project will provide up to 9.78 billion gallons (30,000 acre- feet) of purified water, per year, from the Donald C. Tillman Water Reclamation Plant in Van Nuys to the Hansen and Pacoima Spreading Grounds in the eastern San Fernando Valley. The water will be infiltrated into the groundwater basin where it can eventually be pumped and supplied to homes for drinking and non-drinking uses. This project will provide enough water to supply 90,000 single family homes in Los Angeles per year.
The GWR Project supports the Mayor’s goals to be more drought-resilient and less dependent on purchased imported water. The goals are also consistent with LADWP’s 2010 Urban Water Management Plan that includes efforts to increase the supply of recycled water in Los Angeles to 19.2 billion gallons of water (59,000 acre- feet) by 2035.
Groundwater Replenishment: How it’s done
Hansen Spreading Grounds in the eastern San Fernando Valley
DID YOU KNOW?
One acre-foot is 326,000 gallons of water and is enough to serve three single family homes in L.A. for one year.
Groundwater replenishment is the process of refilling and recharging groundwater aquifers with a water source that can eventually be pumped and supplied to homes for drinking.
Spreading grounds can be likened to football field-sized bowls with layers of natural permeable materials that allow water to percolate underground to reach natural aquifers, or groundwater basins, that serve as large-capacity storage. Currently, the San Fernando Groundwater Basin
is replenished primarily by stormwater. The GWR Project will augment stormwater capture with purified water for infiltration.
The City has four water reclamation plants that collectively receive up to 350 million gallons of water per day (or 392,000 acre-feet per year). Approximately 75,000 acre-feet of this water is currently used for non-drinking uses such as irrigation, commercial and industrial uses, seawater intrusion injection, and environmental benefits such as maintaining Lake Balboa, Wildlife Lake and the Japanese Garden in Van Nuys. The City is aggressively pursuing projects, including the GWR Project, to optimize the use of recycled water in the City.
Donald C. Tillman Water Reclamation Plant Improvements
The GWR Project will include the construction of advanced water purification facilities at Donald C. Tillman Water Reclamation Plant to treat the recycled water and half a mile of 24-inch pipeline for brine discharge.
Currently, recycled water for non-drinking uses is produced through a multi-step process that includes breaking down debris and organic matter as well as chlorine disinfection. This process ensures the recycled water meets regulations for irrigation as well as for commercial/industrial and environmental uses