Desalination for Marin County
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Transcript of Desalination for Marin County
Desalination for Marin CountyDesalination for Marin County
Paul HellikerGeneral Manager
Marin Municipal Water District
North Bay Watershed Association
April 5, 2007
Paul HellikerGeneral Manager
Marin Municipal Water District
North Bay Watershed Association
April 5, 2007
2-Minute History of MMWD Water2-Minute History of MMWD WaterAnnual Rainfall: 1879 through 2001
1912
MMWD formed
1948
Bon Tempe
1953
Kent
1960
Nicasio
1976
First Russian River Imports
1918
Alpine
1971
Measure B Fails
1977
Richmond Bridge Pipeline
1979
Soulajule
1982
Kent Lake Raised
1990
Pilot De-Sal Plant
1991
Measure W Fails
1992
Measure V Passes
1996
Lagunitas Creek
Settlement
Reservoirs72%
Russian River (via NMWD )
26%
Recycled2%
Current MMWD SuppliesCurrent MMWD Supplies
Supply will decrease 25%
Climate uncertainties
Highcost
Projected Supply and DemandProjected Supply and Demand
Current Yield
Future Yield
Acre-feet1987 Demand
0
5000
10000
15000
20000
25000
30000
35000
2002 2005 2010 2015 2020
Projected 2020 ScenarioProjected 2020 Scenario
Current supply deficit: 3,200AF Demand increase: 1,560AF Projected loss of NMWD
capacity: 2,300AF Total projected deficit: 7,060 AF
Current supply deficit: 3,200AF Demand increase: 1,560AF Projected loss of NMWD
capacity: 2,300AF Total projected deficit: 7,060 AF
MMWD OptionsMMWD Options Conservation
– Remains first choice– Already achieved 25% savings– BMPs implemented and very aggressive tiered rates– Additional reductions may cost more than other options
Recycling– Currently have many innovations in place– Expansion complicated by cost and water quality issues
Imports– Endangered species protection limitations– Least costly now – likely increase
Desalination– Reliable supply– Cost and energy use are major issues
Conservation– Remains first choice– Already achieved 25% savings– BMPs implemented and very aggressive tiered rates– Additional reductions may cost more than other options
Recycling– Currently have many innovations in place– Expansion complicated by cost and water quality issues
Imports– Endangered species protection limitations– Least costly now – likely increase
Desalination– Reliable supply– Cost and energy use are major issues
MMWD PlanMMWD Plan– Proximity to
infrastructure– Mix brine with
wastewater in existing deep water outfall
– Intake water is less saline and is warmer than ocean
– No power plant impacts
– Public ownership– Reduce imports
MMWD Desalination Pilot Program & EIR
MMWD Desalination Pilot Program & EIR
- Nine/Twelve month demonstration and test
- Conventional/MF/UF pretreatment, 4 Reverse Osmosis makes
- Chemical, biological testing of water streams
- Dilution modeling- Fisheries studies- Entrainment analysis
- Nine/Twelve month demonstration and test
- Conventional/MF/UF pretreatment, 4 Reverse Osmosis makes
- Chemical, biological testing of water streams
- Dilution modeling- Fisheries studies- Entrainment analysis
Intake ScreeningIntake Screening
Designed to meet Federal and State criteria for fish protection– 3/32-inch openings– <0.3 fps velocity– airburst cleaning
Located at end of existing 2000-ft pier
Multiple screens for full-scale facility
Designed to meet Federal and State criteria for fish protection– 3/32-inch openings– <0.3 fps velocity– airburst cleaning
Located at end of existing 2000-ft pier
Multiple screens for full-scale facility
Reverse Osmosis (RO) Desalination
Reverse Osmosis (RO) Desalination
Tested four manufacturers
Three RO elements per train
Initial problems with non-standard sizes
All performed acceptably – fewer cleanings with MF/UF
Tested four manufacturers
Three RO elements per train
Initial problems with non-standard sizes
All performed acceptably – fewer cleanings with MF/UF
Bay Fish SamplingSummary of Results
Bay Fish SamplingSummary of Results
Northern anchovy & Pacific herring common in midwater trawl
Bay goby, shiner perch common in otter trawl
Dungeness crab most common invertebrate
Species composition similar to CDFG sampling
Spiny dogfish not collected by CDFG
Long-term CDFG data can be used in the environmental analysis
Northern anchovy & Pacific herring common in midwater trawl
Bay goby, shiner perch common in otter trawl
Dungeness crab most common invertebrate
Species composition similar to CDFG sampling
Spiny dogfish not collected by CDFG
Long-term CDFG data can be used in the environmental analysis
E n v iron m en ta l
Measurement of species composition, seasonal distribution, and densities of icthyoplankton, crab, shrimp, oysters
Twice monthly for 12 months Use Empirical Transport Model,
Adult Equivalent Loss and Fecundity Hindcast models to estimate entrainment impacts
Measurement of species composition, seasonal distribution, and densities of icthyoplankton, crab, shrimp, oysters
Twice monthly for 12 months Use Empirical Transport Model,
Adult Equivalent Loss and Fecundity Hindcast models to estimate entrainment impacts
Pilot Plant Entrainment StudyPilot Plant Entrainment Study
0.000224*200565,866yellowfin goby
N/A4540615,864northernanchovy
0.0002983,0894,6981,860,969unidentifiedgobies
0.00062567,45831,396229,061,594Pacific Herring
ETM:Pm Estimate
Annual AELEstimate
Annual 2FHEstimate
Total AnnualEntrainment
Taxa
Estimated EntrainmentEstimated Entrainment
Results to DateResults to Date
ETM estimates range from 0.02 – 0.06%, well below sustainable harvest level of 30-40%
No northern anchovies in source water – no ETM estimate
No salmon, steelhead or sturgeon larvae were collected
ETM estimates range from 0.02 – 0.06%, well below sustainable harvest level of 30-40%
No northern anchovies in source water – no ETM estimate
No salmon, steelhead or sturgeon larvae were collected
Brine Discharge AnalysisBrine Discharge Analysis
Analyzed near- and far-field dilution of brine in sewage effluent
Brine flows stable, up to 15 MGD Sewage highly variable flow: 2 – 100 MGD Near field dilutions average 200:1, min. of
9:1 Far field dilutions in San Rafael Bay of
1500:1
Analyzed near- and far-field dilution of brine in sewage effluent
Brine flows stable, up to 15 MGD Sewage highly variable flow: 2 – 100 MGD Near field dilutions average 200:1, min. of
9:1 Far field dilutions in San Rafael Bay of
1500:1
Size of the Initial Mixing ZoneSize of the Initial Mixing Zone
Worst Case: 650m x 250m
Mean: 30m x 15m
Brine Mixture BioassaysBrine Mixture Bioassays Acute bioassays on mysid
shrimp, topsmelt, marine algae at 79%, 27% and 5% brine– No significant impacts
Chronic bioassays on giant kelp, bay mussel, inland silverside at 79% and 27% brine– No significant impacts under
EPA protocol (correct salinity)– Sublethal impacts for high-
brine mix– No major differences from
sewage effluent alone
Acute bioassays on mysid shrimp, topsmelt, marine algae at 79%, 27% and 5% brine– No significant impacts
Chronic bioassays on giant kelp, bay mussel, inland silverside at 79% and 27% brine– No significant impacts under
EPA protocol (correct salinity)– Sublethal impacts for high-
brine mix– No major differences from
sewage effluent alone
Water Supply AnalysisWater Supply Analysis
Testing for:– 100 Regulated compounds or compounds that require
monitoring – 250 non-regulated compounds – An additional 100 non-regulated compounds specific
to SF Bay (incl. flame retardants, algal toxins)– E-screen bioassay
6,000 Data Points to Evaluate Water Quality and Treatment Performance
Testing for:– 100 Regulated compounds or compounds that require
monitoring – 250 non-regulated compounds – An additional 100 non-regulated compounds specific
to SF Bay (incl. flame retardants, algal toxins)– E-screen bioassay
6,000 Data Points to Evaluate Water Quality and Treatment Performance
Desalinated Water Quality ResultsDesalinated Water Quality Results
ConstituentsMaximum
Contaminant Level (MCL)a
SF Bay Watera Desalinated Watera
Existing MMWD
Sourcesa
Sodium N/A 7,100 21 18 – 20
Chloride 250b 12,000 20 8 – 21
Total Organic Carbon (TOC)
2c 0.86 ND 1 – 2
Boron 1d 2.3 0.2 ND – 0.28
Ethylene Dibromide
0.00005 0.00002e ND ND
Mercury 0.002 ND 0.0003e ND
a - ppmb – Federal Secondary (aesthetic) Standardc – based on MMWD source water qualityd – CA DHS notification levele – 4 of 5 samples tested non-detect
Detailed List of Constituent Sample Results Available
Energy for Desalting Seawater is Similar to Common Appliances
Energy for Desalting Seawater is Similar to Common Appliances
At 7.15 kWh/1000 gal seawater desalination requires only 1.9 kWhr/day of power to produce 270 gallons per day.
81 Watts
1.9 kWh/day
2.4 kWh/day
140 Watts
3.4 kWh/day
75 Watts
1.8 kWh/day
100 Watts
2.4 kWh/day
100 Watts avg.
On average, MMWD households use 270 gallons of water per day
Desal would be approx. 0.7% to 3% of Annual Marin Energy UseDesal would be approx. 0.7% to 3% of Annual Marin Energy Use
0200400
600800
10001200
140016001800
Current MMWDEnergy Use
Desal (AvgConditions)
Desal(Drought
Conditions)
Marin CountyEnergy Use *A
nn
ua
l En
erg
y U
se
, Mill
ion
kW
hr
pe
r y
ea
r
* From California Energy Commission for year 2000
Desal Energy is like an extra lightbulb in every Marin homeDesal Energy is like an extra
lightbulb in every Marin home
Average operation would be like an extra compact fluorescent bulb on all the time
Drought operation would be like a standard 100-W bulb on all the time
MMWD will be considering renewable power to supply this energy need
Average operation would be like an extra compact fluorescent bulb on all the time
Drought operation would be like a standard 100-W bulb on all the time
MMWD will be considering renewable power to supply this energy need
• Desalination facility: $81-121 million• Non-construction costs (permitting, construction
management, etc.): $7-10 million• In-system distribution improvements (Phases IV
and V): $22 - 42 million
Total $110 - 173 million
Annual operating costs: $4 – 12 millionNormalized cost: $2,433 - $2,023 per acre-foot
• Desalination facility: $81-121 million• Non-construction costs (permitting, construction
management, etc.): $7-10 million• In-system distribution improvements (Phases IV
and V): $22 - 42 million
Total $110 - 173 million
Annual operating costs: $4 – 12 millionNormalized cost: $2,433 - $2,023 per acre-foot
Cost of Desalination OptionCost of Desalination Option