View File - Development Services - City of Oxnard

WATER RESOURCES TECHNICAL REPORTgroundwater in the Oxnard Plain and Pleasant Valley area. Opportunities for bothcoastal and inland configurations would be considered. As needed to meet agriculturalwater demands, the City would recover the directly injected water either from injectionwells or other wells.• Concentrate Collection System. A new concentrate 3 collection system would bedeveloped to serve the AWTF, the regional desalter, and various existing industrialbrine producers. The concentrate collection system would collect the reverse osmosis(RO) concentrate produced by these facilities instead of allowing it to discharge into theexisting City sewer system. Because the source of secondary effluent for the GREATProgram is the Oxnard WWTP (fed by the City sewer system) the quality of recycledwater produced by the treatment program is dependent upon sewer system inputs. Theconcentrate would be directed to the Oxnard WWTP outfall for disposal.• Permeate Delivery System. A new permeate 3 distribution system would be developedto provide high quality water to industrial users. This would reduce the need to provideRO treatment of City potable water and reduce discharges of concentrate to thecollection system.• Concentrate Disposal. Tertiary filter backwash from the TTF and concentrate from theAWTF and regional desalter would bypass treatment at the Oxnard WastewaterTreatment Plant to avoid contributing to the high TDS levels of the wastewater influent.Instead, backwash and concentrate would be directly disposed into the Pacific Ocean viathe existing Oxnard WWTP outfall.Section 4.3, Phase 1 Elements, and Section 4.4, Phase 2 Elements, describe the generallocation and specific elements of the GREAT Program, to be developed and operated intwo phases.4.3 Phase 1 ElementsWhile full build out of the GREAT Program (i.e. implementation of both Phases 1 and 2) isone of the recommended elements of the City’s Capital Improvement Program to meetprojected water supply needs through year 2020 (Water System Master Plan, January 2003),Phase 1 is intended to construct and implement facilities at a scale sufficient to meet theCity’s near-term needs. In addition, if Port Hueneme Water Agency (PHWA) participates inthe GREAT Program and the Brackish Water Reclamation Demonstration Facility (BWRDF)is converted to advanced treatment of tertiary treated water, Phase 1 would service PHWApotable water customers currently served by the BWRDF. Construction of Phase 1 facilitiesis anticipated to occur over a period of approximately 32 months (2.5 years).4.3.1 Tertiary Treatment FacilityThe Oxnard WWTP (6001 South Perkins Road) currently treats 22 mgd of wastewater tosecondary treatment standards. Up to 5 mgd of the treated wastewater would be diverted3 In situations where brackish groundwater is treated with membrane filtration technology, two products are produced:“permeate” and “concentrate.” Permeate is produced through the removal of salts and is intended for consumption by varioususers. Concentrate is the portion that contains the concentrated salts and requires disposal. The terms “brine” and“concentrate” are used interchangeably for the purposes of discussion in this document.W112003002SCO LW1458.DOC/ 033390002 51