View File - Development Services - City of Oxnard

WATER RESOURCES TECHNICAL REPORTdelivery system along Hueneme Road to the pilot ASR injection well. The pipeline runsperpendicular to Hueneme Road, and the City would obtain an easement for portions of thepipeline outside the road right-of-way.A new turnout from Mugu Lateral may be required to provide the necessary potable waterfor blending prior to injection. Blending options are further discussed below. If BlendingOption 2 is implemented, a connection to the Mugu Lateral of the Oxnard-HuenemePipeline would be required. The location of the Turnout from Mugu Lateral is shown inFigure 4-2. The Turnout from Mugu Lateral would consist of 1,800 linear feet of 10-inchdiameterpipeline and occur primarily outside existing road right-of-way.Blending Station (Blending Option 2). As discussed previously, prior to groundwaterinjection, recycled water produced by the GREAT Program must comply with draft DHSgroundwater recharge regulations. DHS has recently developed draft regulations dated July21, 2003 that comprise the most current regulation of recharge of groundwater with recycledwater. These draft regulations, once finalized, are planned to supercede the 1978 DHSregulations. The GREAT Program would be in compliance with the current regulations andthe draft regulations, once finalized. To meet the requirements of the regulations, it isassumed that a 50/50 mixture of recycled water and higher quality potable water would beinjected into the groundwater aquifer at the pilot ASR injection well. Blending of potableand recycled water for groundwater injection at the pilot ASR injection well could beaccomplished in two ways. Blending Option 1: Blending at AWTF is described in Section2.3.2, Advanced Water Treatment Facility: Upgrades to BWRDF. Blending Option 2 isdiscussed below.Blending Option 2 would include construction of a blending station at the pilot ASRinjection well. Blending would occur in aboveground piping using potable water from theMugu Lateral of the O-H pipeline. The blending station would consist of an advanced watertreatment pipe approximately 12 inches in diameter and a potable pipe approximately8 inches in diameter. Each pipe entering the blending station would have a flow controlvalve and flowmeter.Pilot ASR Injection Well and Equipment. The pilot ASR injection well would be designed toaccommodate injection and extraction and would be completed to a depth of approximately1,200 feet. The well would be approximately 12 to 14 inches in diameter. The actual screeneddepth would be determined during drilling.The pilot ASR injection well would be equipped with injection and extraction equipment.Extraction equipment would be critical for performing periodic well development tomitigate clogging and maintain well performance. The actual rates and duration of injectionand extraction during pilot test activities would be determined during detailed design. Thewell is planned to be capable of injecting and extracting up to 620 gpm. Injection would beperformed using potable and reclaimed waters. Developing data for both water qualitieswould be important to address DHS regulations for future ASR operations that areconducted as part of Phase 2.Observation Well. One observation well would be installed to monitor water levels andwater quality before, during, and after pilot ASR testing. Discrete depth-specific monitoringwould be performed, consistent with recent United States Geological Survey (USGS)W112003002SCO LW1458.DOC/ 033390002 57