Post on 30-Mar-2018
transcript
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West Basin’s Ocean Water
Desalination Program
Present and Future of
Ocean Water Desalination
Diane Gatza Desalination Project Engineer
March 4th, 2015
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West Basin Leadership
• Five person Board of elected Directors – Division I Harold C. Williams – Division II Gloria D. Gray – Division III Carol W. Kwan – Division IV Scott Houston – Division V Donald L. Dear
• Director Gray is the current President • Elected to four year term by the people
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West Basin Service Area
~900,000 people 17 cities 185 square miles
West Basin Water Supply Portfolio
Ground Water
1947
Imported Water Groundwater
West Basin Water Supply Portfolio
1990
Imported Water Groundwater
Recycled Water
Conservation
West Basin Water Supply Portfolio
2015
Imported Water Groundwater
Recycled Water
Conservation
Ocean Water Desal
West Basin Water Supply Portfolio
2020
• By 2020, shift local supply from 33% to 66%
• Avoid water supply fluctuations caused by: – Environment – Weather – Natural disasters – Competing interests
2x
20 MGD
2x
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5
4
3
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Tertiary Water
Reverse Osmosis: Double Pass
Reverse Osmosis: Single Pass
Nitrified Water
Indirect Potable Reuse: Barrier Water
Designer Waters
Conservation
Commercial & Industrial
Commercial Restroom – Retrofit
Cash 4 Kitchens Recirc & Save
Ocean-Safe Car Wash Landscape
Turf Removal Surveys
Controller Installations Ocean Friendly Demo
Gardens
Toilet Distributions Ocean Friendly Classes
Landscape Surveys Smart Controllers &
Rebates Sprinkler Nozzles
Residential
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Poor Start To WY 2013
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Conditions Are Better This Year
www.westbasin.org January 2014
www.westbasin.org January 2015
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Desalination Objectives and Steps
• Improve reliability • Reduce dependence on imported water • Diversify water supply portfolio • New source of local potable water
3. Comprehensive Planning
2. Demonstration Project (2010 – Present)
1. Piloting (8 Years)
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Responsible Desalination
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• Economics
• Energy Efficiency
• Education
• Environment
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Economics
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1947 1990 2000 2011
30x 10x 2x 1.8x
2020
~1.5x
Economics Desal Costs vs. Imported Costs
IPR Recycled
WB
$1,531 A/F
Desal
$1,887 A/F
20 MGD
Desal
$1,579 A/F
60 MGD
Economies of Scale Desal Costs vs. Recycled Water Cost (West Basin)
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• Water Energy Nexus • Thermal desal • Micro-grid approach • Regional desalination planning
Economic Research Opportunities Future Alternatives
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Energy Efficiency
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Energy Consumption
Reverse Osmosis With ERI Energy Recovery Device
Permeate 1 MGD
1 MGD
883 psi
1 MGD 25 psi
903 psi
1 MGD 2 MGD Feed Water 2 MGD
25 psi
1 MGD
1 MGD
25 psi
1 MGD
857 psi Concentrate
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RO Process: •ERI 43% less energy than no energy recovery
•ERI 12% less energy than a pelton wheel
Total Facility: •ERI 35% less energy than no energy recovery
•ERI 9% less energy than a pelton wheel
Energy Consumption
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Energy Assessments • Nano H2O membrane testing
– Based on water quality objectives there is no energy or $ savings for West Basin case
• Optimized operating parameters – Red tide events – High wind and turbidity events
• Hybrid RO membrane approach • Conceptually evaluating thermal distillation
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• Forward Osmosis • Pressure Retarded Reverse Osmosis (RO-PRO) • Renewable Energy
• Wave Energy
Energy Research Opportunities Future Alternatives
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Environment
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Desal Pilot Facility (2002-2009)
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Pilot Conclusions • Demonstrated performance through
seasonal variations of water quality • Determined MF/UF is a viable
pretreatment to RO • No process challenges due to
– Hyperion Effluent – Storm water – Red Tide
• Developed design criteria for Demonstration Facility
• Identified environmental impacts as a research need
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Desal Demonstration Facility (2010-2014)
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• Certify Processes at a Full-Scale Level • Process Optimization • Energy Minimization • Regulatory Compliance • Water Quality Assessment
• Distribution Integration • Environmental protection • Policy Development • Research Facility
Demonstration Facility Process
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Environment Intake
• Impingement • Based on velocity
• 0.5 ft/s • Entrainment
• Organism size dependent • Large species • Adult and juvenile marine life • Larval stage
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Impingement and Entrainment
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• Impingement - Velocity • Entrainment - Size 1. How to quantify larval entrainment impacts? 2. Do screening technologies provide marine protection?
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Larvae in Sample Area
(v1)
Ocean Current Flow
Larvae Entrained
(v2)
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Intake Effects Assessment Study
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Intake Effects Assessment Study
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Wedge Wire Screening • Wedge wire screens DO reduce entrainment
– Screen out large and adult marine life – Screen out mature larvae that is most likely to make it
to a reproductive adult stage – Smaller intake size = fewer number of days a species
has the ability to be entrained
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Age (days)
Head Capsule
Size (mm)
2.00
1.00 Distance (m)
2.00 mm
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Environment Discharge
• Ambient ocean concentration is doubled (ie 50% recovery) • Could be toxic? • Increasing concentrations for other constituents
• Discharge is denser than ambient seawater • Tendency to settle on the ocean floor • Impact to benthic organisms
• Long Term Effects • Best Available Technology –Diffuser Entrainment
• Diffusers? • Dilution?
Ocean Surface
Concentrate Flow
Brine Plume
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• Assess brine impacts on marine organisms • Short Term Study • Long Term Study • Acute and Chronic Toxicities
• Survival • Growth, weight, behavior, etc.
High Salinity Sensitivity Study
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EPISODE 1
33, 42, 51, 60, 70 PPT
EPISODE 2
33, 36, 39, 41, 45, 50 PPT
EPISODE 3
33, 36, 39, 42, 45, 60 PPT
High Salinity Sensitivity Study
High Salinity Sensitivity Study Short Term Research
• Life stages • Invertebrates: Adult
• Exposure Duration • 72 hours – 7 days
• Endpoints • Survival • Acute Effects
High Salinity Sensitivity Study Long-Term Study
• Life stages • Fish: Juvenile • Invertebrates: Adult
• Exposure Duration • Two weeks at each salinity • 3 days at ambient in between
• Endpoints • Survival • Growth of two fish species
• Sanddabs • Sea bass
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1. Species with highest exposure risk, e.g. bottom dwellers, are least sensitive 2. No observable effects for 24 hours - 7 days at 42.5 parts per thousand (ppt),
average ambient salinity is 33 ppt 3. Scientific EPA endorsed study
Conclusions Short Term Research (lab)
1. West Basin first to perform this innovative study 2. Food dispersion between species important 3. Same life-stage organisms for each trial 4. All species tolerant to salinities up to 42.5 ppt 5. Site specific species (demersal and pelagic fish) tolerant to highest salinity
tested at 47.5 ppt
Long Term Research (aquarium)
Brine Diffuser Entrainment Study
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Brine Diffuser Entrainment Study
Completed Research
• Harmful Algal Bloom and Marine Biotoxin Study- DWR
• Pilot Facility Final Report – West Basin
• High Salinity Sensitivity Study– West Basin
• Brine Diffuser Entrainment Study – West Basin
• Intake Effects Assessment Study– West Basin
• Water Quality Integration Study– West Basin/ MWD
• Desalination Energy Intensity – West Basin
• Energy Consumption Modeling Study – Water
Research Foundation
Ongoing/Upcoming Research • Energy Reducing Technologies Study - WateReuse
• Habitat Value Assessment – West Basin
• Intake Bio-fouling and Corrosion Study – MWD
• Subsurface Intake Study – USBR
• IM&E Mitigation Development Grant – WateReuse
• Desalination Concentrate Disposal – PAC Participant
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Education
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Education Public Outreach
• Stakeholder briefings to local, state
and federal elected officials
• Free public tours
• Presentations and tours to civic
groups
• “Seeing is believing” positive
reactions and recognize need for
desalination
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Education Public Outreach
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Education Public Outreach
Desalination Policy in the State of California
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• State of desal • 3 operating plants • 1 plant under construction (Carlsbad) • 1 near-term desal construction project (Santa Barbara) • Numerous pilot and demonstration facilities
• 25+ Permits to build an ocean water desalination facility • Lengthy permitting process • Currently no desalination policy exists in the State of California
• Once Through Cooling (OTC) Policy • State Water Resources Control Board
• California Ocean Plan • Amendment Process
• 2011- Present • Expert Panels • Stakeholder Outreach • Circulated an initial draft policy in August 2014 • Final draft to be coming out March 2015
• Policy Framework • Intake Technologies (subsurface and wedge wire) • Discharge zone of initial dilution
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Thank You
Diane Gatza DianeG@westbasin.org
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