Item 27 - Water Supply Assessment for Cabrillo Town Center Project

Home Browse Search

Santa Ana 2020 Urban Water Management Plan arcadis.com 6-24 GAP water, current recycled water users include Mile Square Park and Golf Courses in Fountain Valley, Costa Mesa Country Club, Chroma Systems carpet dyeing, Kaiser Permanente, and Caltrans. The City maintains an agreement with OCWD to supply GAP water to customers where available. 6.6.1.2 OCWD Groundwater Replenishment System OCWD’s GWRS allows Southern California to decrease its dependency on imported water and creates a local and reliable source of water. OCWD’s GWRS purifies secondary treated wastewater from OC San to levels that meet and exceed all state and federal drinking water standards. The GWRS Phase 1 plant has been operational since January 2008 and uses a three-step advanced treatment process consisting of microfiltration (MF), reverse osmosis (RO), and ultraviolet (UV) light with hydrogen peroxide. A portion of the treated water is injected into the seawater barrier to prevent seawater intrusion into the groundwater basin. The other portion of the water is pumped to ponds where the water percolates into deep aquifers and becomes part of Orange County’s water supply. The treatment process described on OCWD’s website is provided below (OCWD, GWRS, 2020). The GWRS first began operating in 2008 producing 70 million gallons of water per day (MGD) and in 2015, it underwent a 30 MGD expansion. Approximately 39,200 AFY of the highly purified water is pumped into the injection wells and 72,900 AFY is pumped to the percolation ponds in the City of Anaheim where the water is naturally filtered through sand and gravel to deep aquifers of the groundwater basin. The Orange County Groundwater Basin provides approximately 72% of the potable water supply for north and central Orange County. The design and construction of the first phase (78,500 AFY) of the GWRS project was jointly funded by OCWD and OC San; Phase 2 expansion (33,600 AFY) was funded solely by OCWD. The Final Expansion of the GWRS is currently underway and is the third and final phase of the project. When the Final Expansion is completed in 2023, the plant will produce 130 MGD. To produce 130 MGD, additional treated wastewater from OC San is required. This additional water will come from OC San’s Treatment Plant 2, which is in the City of Huntington Beach approximately 3.5 miles south of the GWRS. The Final Expansion project will include expanding the existing GWRS treatment facilities, constructing new conveyance facilities at OC San Plant 2 and rehabilitating an existing pipeline between OC San Plant 2 and the GWRS. Once completed, the GWRS plant will recycle 100% of OC San’s reclaimable sources and produce enough water to meet the needs of over one million people. 6.6.2 Wastewater Description and Disposal The City operates and maintains the local sewer system consisting of over 390 miles of pipeline, 7,630 manholes, and two lift stations that connect to OC San's trunk system to convey wastewater to OC San's treatment plants. OC San has an extensive system of gravity flow sewers, pump stations, and pressurized sewers. Collected wastewater is sent to OC San's plants located in the Cities of Huntington Beach and Fountain Valley. OC San’s Plant No. 1 in Fountain Valley has a capacity of 320 million gallons per day (MGD) and Plant No. 2 in Huntington Beach has a capacity of 312 MGD. Both plants share a common ocean outfall, but Plant No. 1 currently provides all its secondary treated wastewater to OCWD’s GWRS for beneficial reuse. The 120-inch diameter ocean outfall extends 4 miles off the coast of Huntington Beach. A 78-inch diameter emergency outfall also extends 1.3 miles off the coast. Table 6-6 summarizes the wastewater collected by the City and transported to OC San's system in 2020.