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: purewatersd@sandiego.gov Call: (619) 533-7572