The San Dieguito Valley Brackish Groundwater Desalination Design Pilot constructs a test well and conducts a one-year pumping test to evaluate aquifer response in both wet and dry climactic conditions and refine the groundwater model and basin water balance. Treatment technologies will be pilot tested to refine treatment design criteria prior to construction of a full-scale brackish groundwater desalination facility. The design pilot will verify: test well locations with pilot borings; water balance of the San Dieguito Valley Groundwater Basin test wells; water quality from test wells for required desalination treatment; and manganese treatment by piloting pre-treatment technologies. Results will confirm the most beneficial and cost-effective approach to full-scale desalination facility construction to increase potable water supplies. Design pilot project components will include: 1) Project management, 2) Pilot hole drilling, zone testing and water quality sampling, and test well construction and development; 3) Data collection and analysis during long-term pump testing (one year), including installation of continuous reading pressure and conductivity transducer; 4) Refinement and update of the groundwater basin model and recalculation of the basin water balance and assessment of water level and water quality changes; 5) Hydrogeologic investigation report; 6) NPDES permitting for design pilot operation; 7) Field testing of manganese pre-treatment system and analysis; 8) Refinement of pre-treatment and reverse osmosis treatment design criteria; and 9) Public outreach and involvement. Successful completion of the design pilot will result in the anticipated construction of the full-scale desalination project beginning in 2021, with operation starting in 2022. The full-scale project will increase OMWD's supply reliability and produce 1,120 AFY of local, droughtproof water supply.
Olivenhain Municipal Water District
The objectives of the San Dieguito Valley Groundwater Basin design pilot are to: 1) Verify test well locations with pilot borings, 2) Verify water balance of San Dieguito Valley Groundwater Basin test wells, 3) Verify water quality from test wells for required desalination treatment, and 4) Verify manganese treatment by piloting pre-treatment technologies.
Project Benefits a Disadvantaged Community (or SDAC):