MIT CEE 1.011 – Project Evaluation Spring Term 2003Susan Murcott, Lecturer 1Orange County Groundwater Replenishment System’s Environmental Impact AssessmentWhat is the Groundwater Replenishment (GWR) System?GWR is a new project (approved October 2002) of the Orange County Water District (OCWD) and Orange Country Sanitation District (OCSD) to purify, for reuse in groundwater recharge, highly treated wastewater that is currently discharged to the ocean via ocean outfalls. Where is it? Groundwater Replenishment System MapPacific OceanOcean OutfallSpreading BasinsOCSDTreatmentFacilitiesSeawater Intrusion BarrierProposed Site of Advanced Water Treatment PlantGroundwater Basin BoundaryNIrvineAnaheimLos AngelesSan DiegoConstruction Required• High-tech, water purification system at existing site.• 13 mile pipeline from Fountain Valley to Anaheim• New injection wellsAdvanced Water Treatment Plant• High-tech, water purification system producing “ultra-pure,” high quality water• Technology used in industry for years– Microfiltration – food, medicines– Reverse Osmosis – bottled water– Ultraviolet disinfection – for medical instruments• Similar projects in VA, TX, AZ, FL, HI, Europe and elsewhere.First Purification Step• Microfiltration used since WW II, in blood dialysis• Used in computer chip, food and pharmaceutical manufacturing• Used to purify fruit juices & baby food• Used to sterilize medicines that can’t be heated• First used to treat water by Disneyworld in Orlando• Excellent pre-treatment before reverse osmosisMicrofiltration (MF)MIT CEE 1.011 – Project Evaluation Spring Term 2003Susan Murcott, Lecturer 2Second Purification Step• Technology used by bottled water companies• Used in homes, boats, & by OCWD at Water Factory 21 since 1975• Forces water under very high pressure thru many plastic sheets of membranes• Demineralizes and purifies waterReverse Osmosis (RO)Third Purification Step• Proven technology – used to sterilize medical instruments• Concentrated light & H2O2creates an advanced oxidation reaction• Appears to be effective against new, emerging contaminants (e.g. pharmaceuticals)• Finally, recharge step is an additional natural barrier of filtration through the ground.• “Multiple barrier” approachUltraviolet (UV) Disinfection plus H2O2GWR Project SchedulePhase III operational. 120,000 af/yr2020Phase II operational. 95,000 af/yr2010Phase I operational. 70,000 af/yr2004Phase I construction begins2002Design phase completion and approval by OCWD/OCSD2001Environmental Impact Assessment (EIA) certified1999GWR research begins1994Why Groundwater Recharge? What’s the Need and Where does Orange County Water Come From?Why Groundwater Recharge? What’s the Need and Where does Orange County Water Come From?Population Growth & Water ShortagesOrange County‘s current population of 2.3 M is predicted to increase to 2.8 M by 2020. • Southern California: will add 7 million by 2020• California: will add 15 million by 2020 - CA will add current population of 8 western states!!!• Unless solutions are found, there will be water shortagesby 2020– Orange County predicts shortages of 180,000 acre-feet per year– CA Department of Water Resources predicts shortages of 2-4 million acre-feet per yearID, MT, OR, WY, AZ, NV, NM & UTOne Acre-Foot (AF) of Water• Enough water to cover a American football field to a depth of one foot• 325,900 gallons (1,200 m3)• Approximately enough water for two families (of 4) for one year• Orange County total water demand (2002) = 500,000 af/yrMIT CEE 1.011 – Project Evaluation Spring Term 2003Susan Murcott, Lecturer 3Where Does Orange County Get Water?• IMPORTED– “State Water” from Sierra Nevada Mountains = from Owens River and Mono Lake– “State Water” from Northern California – Colorado River Water • LOCAL– Santa Ana River – Groundwater How Much Water Does Orange County Use?• Current water demand = 500,000 af/yr• Projected water demand by 2020 = 680,000 af/yr• 40% = “State Water” + Colorado River Water• 60% = Groundwater Colorado River - shared with 7 Western states and Mexico• Hoover Dam and Lake Mead Colorado River is Divided Up• 16.4 M af/yr = original calculation when the Colorado Water Compact was negotiated.• 14 M af/yr = more accurate measurement• 12 M af/yr = drought years (e.g.1930s)• Total Allocation = 16.5 M acre-feet/year!!!– 7.5 M af/yr to upper basin states – 5.5 M af/yr to California, – 2.0 M af/yr to Nevada, and Arizona. – 1.5 M acre-feet to Mexico• Bottom Line – all parties must use less Colorado River water in the future!Orange County’s Mix of Groundwater and Imported Water• North Orange County uses mostly Groundwater provided by Orange County Water District– Basin under North-Central OC– Groundwater basin is a natural storage, filter and piping system – Useable: 1 million acre-feet of water – Filled by Santa Ana River & imported water • South Orange County uses 98% “State Water” (Metropolitan Water District of SoCal (MET) & Municipal Water District OC)– Owens River/Mono Lake, Northern California & Colorado RiverImported Water Cutbacks are coming!!!– State Water Reductions of Northern California Water• Expect loss of 25% or more of supply due to $8 Billion restoration SF-San Joaquin Bay Delta– Colorado River Reductions• CA must cut from 5.5M to 4.4M af/yr by 2016 due to over-allocation demands• Colorado River has many threats from growth, environmental, Native American, salinity, international & pollution fronts– LA/Orange County must leave 10% more water in Mono Lake/Owens River to prevent dust particulate problemMIT CEE 1.011 – Project Evaluation Spring Term 2003Susan Murcott, Lecturer 4GWR Cost and Who Pays?• $600 M over 20 years (1999 dollars)• Grants of $57M are expected of which $37M from State Water Bond approved by California voters in 2000Orange County’s Future Water Options *Cost in 2007Requires special costly piping$3,000Satellite Wastewater Reclamation PlantsSister agencies choice$800 - $2,000 Desalination$600 Rehab Existing H2O Treatment PlantYes!$450- $500* GWR SystemMay not be there$500-$550*Buy “State Water”Trying, but can’t do enoughConservationCommentCost ($/af)OptionBenefits of GWR Plan• More reliable water– Supports existing & new business & jobs– Provides water for recreation like golfing, horseback riding–