Desalination & Clean Water Technology Industry-Government Forum August 23, 2012 Roger Bailey Public Utilities Director
Feb 24, 2016
Desalination & Clean Water Technology Industry-Government
Forum
August 23, 2012
Roger Bailey Public Utilities Director
Policy Development
Water Supply Reliability Local Supply Development Legal Constraints Natural Disasters
State and Federal Regulations Water and Waste Water Treatment Processes Affordability for Ratepayers
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Water Supply: Seven-Year Average
Local Surface Water 7.20%
Imported Water 77.4%
Conservation 12.7%
Recycled Water 2.70% Groundwater 0.10%
Water Supply Reliability
Limited local supplies Increasing cost of imported water Pumping restrictions Recurring drought conditions Internal population growth Natural disasters
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State and Federal Regulations
Drinking Water Quality Upgraded all three water treatment plants
Alvarado and Miramar – Ozone treatment Otay – Chlorine Dioxide
National Pollutant Discharge Elimination System Permit Modified Permit allows advanced primary treatment
at Pt. Loma Waste Water Treatment Plant
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State and Federal Regulations
Greenhouse Gas Emission Reduction AB 32 requirements Energy/water/waste water nexus Need technologies to improve reliability, treatment
while reducing energy consumption Water Conservation Mandate
20% by 2020 “Low hanging fruit” is taken – support new ideas
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Water and Waste Water Treatment
Upgraded all three water treatment plants Alvarado and Miramar – Ozone treatment Otay – Chlorine Dioxide
Modified Permit allows advanced primary treatment at Pt. Loma Waste Water Treatment Plant Completed Recycled Water Study in July 2012 Condition of Coastal Commission approval for 2010
NPDES permit
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Operate one MGD facility San Vicente Reservoir study Define regulatory requirements Conduct energy & economic
analysis Public education & outreach
COMPONENTS
OUTCOMES
Water Purification Demonstration Project
Validate treatment process Gain regulatory approval Evaluate cost Public acceptance
Recycled Water Study
Identify opportunities to increase recycling of wastewater for Indirect Potable Reuse (IPR)and Non-Potable Reuse (NPR) for a 2035 planning horizon
Determine the extent recycling can reduce wastewater flows to the Point Loma Wastewater Treatment Plant
Determine implementation costs
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Recycled Water Study
Two Forms of IPR Evaluated: Groundwater Recharge Reservoir Augmentation
Findings: Groundwater basin size and data insufficient to
determine potential recharge projects. Revisit when more data is available
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Recycled Water Study
Findings: Two reservoirs deemed large enough to
provide retention times within range required in draft groundwater recharge regulations
San Vicente Reservoir Otay Reservoir
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Recycled Water StudyPrioritized Next Steps
Finalize the Water Purification Demonstration Project (Dec 2012)
Conduct Facility Siting Studies Evaluate cost sharing concepts Prepare Financing Plan Integrate into Point Loma Waiver Process Confirm Otay Reservoir IPR Potential
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Affordability for Ratepayers
Water and waste water service are fee based Revenues for the system are derived from
customers’ bills The City has had success when State and Federal
grant funds are available Future enhancement to system must be
financially beneficial for ratepayers
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Questions
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Back up slides to follow
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San Diego Water Reuse Timeline
1993 City & County Water Authority proposeWater Repurification Project
1994 Congress passes the Ocean Pollution Reduction Act, allowing the City to reapply for a waiver that is later granted
1994-1998 Planning, regulatory reviews & conditional approval (DPH), preliminary design on project (20 TAF or 18 MGD)
Fall 1998 Water Repurification Project becomes an issue in several closely contested political campaigns
Spring 1999 Project cancelled by City Council
San Diego Water Reuse Timeline
2002-2004 City enters into a settlement agreement with environmental groups committing to:
Evaluate improved ocean monitoringPilot test biological aerated filtersConduct study on increased water reuse
2004-2005 City undertakes Water Reuse StudyOctober 2007 City Council votes to proceed with the
Demonstration Project
Water Purification Demonstration Project
November 2008 City Council approves temporary water rate increase to fund $11.8 million project
January 2009- Temporary water rates in effectAugust 2010
Membrane Filtration Side-by-side microfiltration (MF) &
ultrafiltration (UF) to test effectiveness prior to reverse osmosis
Pressurized hollow fiber membranes MF nominal pore size: 0.10 microns UF nominal pore size: 0.02 microns
Reverse Osmosis: Step Two Same technology used by
bottled water companies Forces water under high
pressure through sheets of plastic membrane
Demineralizes and purifies water
Ultraviolet Light/Advanced Oxidation Process (UV/AOP)
RO permeate combines and feeds UV/AOP
Hydrogen peroxide (30%) injected upstream of UV at 3 mg/l
UV system utilizes low pressure/high output lamps
Single reactor, 72 lamp configurationUltraviolet (UV) plus H2O2 Disinfection
Testing & Monitoring Plan Objectives Demonstrate proposed water purification technology will
produce water quality that meets public health and reservoir augmentation criteria
Evaluate nutrient removal performance of the AWP Facility treatment train
Demonstrate integrity monitoring techniques and performance reliability measures
Monitor and collect operational and maintenance requirements of the AWP Facility equipment
Water Quality Results - Overview Exceptional overall water quality,
met all project treatment goals Purified water met all drinking
water standards Equipment at each step in the
treatment process is performing properly
San Vicente Limnology and Reservoir Detention Study
Dam to be raised 117 feetCurrently 90,000 acre-feet242,000 acre-feet after dam raiseConstruction duration 2009-2013Augmentation would improve water quality
InformationVisit: www.purewatersd.org Email: [email protected] Call: (619) 533-7572