View File - Development Services - City of Oxnard

WATER RESOURCES TECHNICAL REPORTSeasonal storage of potable water supplies would be implemented to provide additionalhandling capacity for the potable water supply of the City. Seasonal storage means thatwater would be injected and then recovered on an annual basis. Seasonal storage wouldprovide the City with additional handling capacity for its potable water supply in lieu ofincreasing the capacity of its existing pipeline distribution system. Potable water wouldbe injected and recovered from seven to eight potable ASR wells located on City WaterYard property. Four existing ASR wells would be retrofitted, and three to four new ASRwells would be constructed.• Regional Desalter. A new regional groundwater desalination facility (regional desalter)would be constructed to treat groundwater for potable water service to the City andPHWA through the existing water delivery system. The City currently blends higherquality imported water with groundwater to provide a balance between quality andcost. The new regional desalter would allow the City to meet its potable water qualityobjectives without relying solely on blending with the higher quality imported water. IfPHWA participates in the GREAT Program, the desalinated water produced by theregional desalter would replace the potable water that the BWRDF currently supplies tothe PHWA service area. Also, the recycled water deliveries described above wouldreduce groundwater pumping in the Pleasant Valley area, thereby generating unusedgroundwater credits that could be transferred to the City and also serve as the sourcewater for the regional desalter.• Blending Station No. 5. The City currently blends higher quality imported surfacewater with groundwater on a one-to-one basis at one of four blending stations toprovide a balance between quality and cost. The City has identified a fifth additionalblending station location in the southern portion of the City that would provideimproved water supply reliability, water quality, and hydraulic efficiencies and assist inmeeting peak hour and fire flow demands for water. The blending station would includepipeline facilities to convey blended water to the existing potable water distributionsystem of the City.• Concentrate Disposal. Consistent with current City wastewater treatment plantoperations, tertiary filter backwash from the TTF and concentrate from the AWTF andregional desalter would be processed through the WWTP headworks for treatment andthen disposed into the Pacific Ocean via the existing Oxnard WWTP outfall.4.2.2 Phase 2 SummaryIn Phase 2, the treatment or conveyance capacities of the Phase 1 project elements generallywould be expanded. In addition, the pilot aquifer storage and recovery element would beconverted to full-scale ASR. Opportunities for both coastal and inland recycled wateraquifer storage and recovery have been identified. Phase 2 would also consist of a newconcentrate collection system and permeate delivery system. The Phase 2 elementsdiscussed below are summarized in Table 4-1 and shown in Figure 4-3.• Aquifer Storage and Recovery Expansion. The Phase 2 aquifer storage and recoveryelement will be dependent upon results of the pilot ASR program conducted underPhase 1. However, it is anticipated that either existing water supply wells or new aquiferstorage and recovery wells would be used to recharge and potentially recoverW112003002SCO LW1458.DOC/ 033390002 50