View File - Development Services - City of Oxnard

WATER RESOURCES TECHNICAL REPORThydrogeologic studies on the Oxnard Plain. The observation well would be drilled to adepth of approximately 1,200 feet.Extracted Water Facilities. Pilot ASR injection well storage facilities would consist of a20,000-gallon tank or open basin for periodic maintenance during well operation. To controlclogging during normal operation, water would be pumped periodically to the tank or openstorage basin to allow sediments to settle. Water stored in the tank would be disposed ofonsite or discharged offsite in accordance with NPDES permit regulations. If the open basinwere implemented, water would percolate into the ground surface. Extracted water facilitieswould occur within the 1-acre pilot ASR injection well site. Recovered groundwaterextracted from the pilot ASR injection well would be transferred to the PTP via the recycledwater delivery system during pilot ASR program injection-extraction cycles.Potable Water ASRThe approach to implementing potable water ASR would include retrofitting four existingwells (Well Nos. 20, 21, 22, and 23) and constructing three to four new wells at the CityWater Yard. The potable water ASR wells would extract (and at times inject) water from(and at times into) the UAS and LAS. Existing Well Nos. 20 and 21 are completed in theLAS, and Well Nos. 22 and 23 are completed in the UAS. These four existing wells have acapacity of approximately 3,000 gpm. The new potable water ASR wells would becompleted in the UAS and would each have a capacity of approximately 1,000 to 3,000 gpm.The locations of the existing wells to be retrofitted (at the City Water Yard) are shown inFigure 4-2. The new potable water ASR wells would be located on the perimeter of CityWater Yard property as shown in Figure 4-5. Three wells are proposed to be sited along theperimeter of the site. If a fourth well is determined to be needed, it would also be locatedalong the perimeter of the site.Facilities associated with the potable water ASR include:• Conveyance facilities to convey potable water to the potable ASR wells within theCity Water Yard• ASR well and injection-extraction pumping equipmentApproximately 800 feet of 24-inch miscellaneous yard piping would be required todistribute potable water throughout the City Water Yard. ASR well injection and extractionequipment would be similar to that described above for pilot ASR (Section 4.3.4.1).4.3.5 Regional DesalterAs discussed in Section 4.2 GREAT Program Overview, the delivery of recycled water forirrigation would generate groundwater storage credits through (1) displacement pumpingof groundwater on the Oxnard Plain and (2) groundwater injection conducted as part ofaquifer storage and recovery. The groundwater pumping allocations not used byagricultural interests and groundwater storage credits gained through aquifer storage andrecovery represent a new local water source that the City could supply to its customers tomeet potable demand. The unused groundwater pumping allocation and groundwaterstorage credits could be redeemed through the Fox Canyon Groundwater ManagementAgency, the agency that manages the region’s groundwater supply. The groundwater notW112003002SCO LW1458.DOC/ 033390002 58