Brackish Desalination – Water Supply Planning for … - Brackish Desal... · 2017-02-07 · Brackish Desalination – Water Supply Planning for Resiliency and Growth ... Salt Balance:

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Brackish Desalination – Water Supply Planning for Resiliency and Growth Paul D. Jones II February 2, 2017

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EMWD Agency Overview

• Established in 1950

• Unique agency, serving:

– Water/wastewater/recycled

– Wholesale and retail

• Five district-elected board members

• More than 600 employees

• Annual operating budget of $171 million for FY 2016/2017

• Five year capital program of $461 million FY 2017 – 2021

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EMWD’s Service Area

• 555 square miles

• Population: 795,000

• Moreno Valley to Temecula

• Seven cities and the unincorporated areas

• One of 26 member agencies of The Metropolitan Water District of Southern California (MWD)

• High-growth area that is 38% built-out

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EMWD Services

• Potable Water: Approx. 144,000 accounts – Imported water from the State Water Project

and Colorado River • Directed treated deliveries from MWD • Two Ultra-filtration plants

– Groundwater wells (adjudicated - managed basin)

– Brackish desalination

• Wastewater: Approx. 239,000 accounts – Four regional water reclamation facilities

• Recycled Water: Approx. 300 accounts – 35,617 acre feet sold in FY 2014/2015 – Approximately 10,800 acres of agriculture

irrigated by recycled water

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EMWD’s Retail Water Supply Portfolio

• Balanced Imported/local portfolio: – 54% of total supplies coming

from diversified local sources; – 46% of total supplies are

imported • Recycled water: 100% beneficial

reuse within service area • Brackish groundwater: Two

desalters in operation, – 6,500 AF of potable water from

an otherwise unusable source • Groundwater management:

– Adjudicated Hemet/San Jacinto sub-basin

– GSA for Perris/Menifee Sub-basin

Imported Water 46%

Groundwater 12%

Desalters 5%

Recycled Water 37%

Calendar Year 2016 (119,046 AF)

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Four Key Desalination Program Objectives

• Supply: Develop substantial brackish groundwater (>1,000 mg/l) resources from Perris and Menifee sub-basins ‒ Rising groundwater basin with substantial

natural replenishment ‒ Minimal pumping by other entities ‒ Adjudicated but under GSA

• Groundwater Management: protect groundwater sub-basins from salinity intrusion

• Salt Balance: Achieve net salt balance relative to imported water supplies

• Technology Optimization: Develop advanced brine recovery technologies

Strategic Supply Goal: Expand Brackish Groundwater Desalination to

Provide over 17,500 AF/year to Serve 35,000 Households

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Desalination Supply Objectives and Program Components

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EMWD’s Desalination Program Components

• Initial desalter built in 2002

• Groundwater Wells • Desalter feed pipelines • Treatment facilities

– Menifee and Perris I Desalters

– Perris II Desalter (future)

• Brine disposal – Inland Empire Brine Line – On-site brine recovery

(future)

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Existing Program – Menifee Desalter

• Perris South Basin

• Inland Empire Brine Line

• Feedwater pipelines • 3 production wells

Menifee Desalter – Phase I • 3.1 MGD Reverse Osmosis Desalter • 3,000 AF/year capacity • Operational in 2002

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Existing Program – Perris I Desalter

• Perris South Basin

• Inland Empire Brine Line

• Feedwater pipelines • 9 production wells

Perris I Desalter • 5.6 MGD Reverse Osmosis Desalter • 5,600 AF/year capacity • Operational in 2005

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Proposed Perris II Desalter – Phase I

• New Treatment Facility – 3.6 MGD • Production Facilities – four wells

with combined capacity of 3,000 gpm

• Brine disposal connection • Extended desalter feed pipelines • Shared site/infrastructure

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Brine Disposal

• Constructed by a five agency Joint Powers Authority

• Pipeline is 70 miles – capacity is 30 MGD

• Supports six desalters and industrial dischargers, including:

– Menifee Desalter

– Perris Desalter

• EMWD currently using about 3.5 MGD

– O&M is $1.05 M/yr.

EMWD Desalters

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Brackish Desalination Supply Costs

EMWD Supplies Alternative Supplies

$942 - $1,076

$250

$1,015 - $1,235*

$401

$2,014 - $2,257

$1,079 - $1,295

$0

$500

$1,000

$1,500

$2,000

$2,500

Imported water from MWD

Groundwater Wells

Desalinated Groundwater

Recycled Water (Purple pipe)

Ocean Desalination

Indirect Potable Reuse

Desalinated Groundwater

* Desalination operating costs are $505 per acre-foot

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Desalination Groundwater and Salinity Management Objectives

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Groundwater Basin Management Objectives

Basin Plan Objectives • Hemet /S.J. 320 mg/l (Max Ben Obj.) (500 mg/l) • S.J. Low. Press. • Lakeview Less than • Hemet North 570 mg/l • Perris North • Hemet South 730 mg/l • Menifee Approx. • Perris South 1260 mg/l

EMWD Service Area and Groundwater Basins

N

Hemet – San Jacinto Basin principal groundwater source for four

agencies and Soboba Tribe

Desalters

Rising groundwater

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Salinity Management Objectives

• Current: 2.3 MGD of desalter brine disposal through the Inland Empire Brine Line

• Proposed: 4.5 MGD disposal at full expansion

• Current salt removal ‒ 25,000 Tons Annually ‒ Slight Net Import into Region

with Imported Water

• Ultimate salt removal goal ‒ 55,000 Tons Annually ‒ Net Export

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Achieving Salt Balance

Imported Water (Average Year) SWP = 46,900 af/yr (66%) 250 mg/l or 680 lbs/af = 15,900 t/y CRA = 24,000 af/yr (33%) 520 mg/l or 1,360 lbs/af = 16,400 t/y 32,300 t/y Current Desalting and Brine Discharges EMWD Menifee and Perris I Desalters - 2.3 MGD brine 25,000 t/y Other industrial dischargers

Intl Rectifier - 0.05 MGD (30,000 mg/l) 2,300 t/y Inland Empire Energy - 0.2 MGD (6,000 mg/l) 1,800 t/y

29,100 t/y

Imported Supply Salt (TDS – mg/l) Lbs. of salt/acre foot Colorado River Water ~500 to 700 mg/l 1,360 to 1,900 lbs/af

State Water project (current) ~250 mg/l 680 lbs/af

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Technology Optimization Objective - AquaSel™ Brine Concentration Pilot Project

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Background

• Pilot Study of the AquaSel Brine Concentration Technology was completed in August 2015

• AquaSel is a proprietary process by GE which uses Electrodialysis Reversal (EDR) and a precipitator

• Tested 10 gallons per minute (gpm) pilot plant

• Pilot testing was conducted over a nine-month period

• Peer review by U.S. Bureau of Reclamation

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Summary of Findings

• Typical membrane fouling and hydraulic issues were mitigated

• Achieved significant operation time – 1,890 hours of operation – 320 hours of continuous run time

• Sustained operation with occasional downtime

• Average TDS of pilot plant product water was approximately 1,500 mg/l – Compatible with raw well water for

blending

Achieved 95 percent overall recovery of brackish groundwater through improved brine concentration

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Next Steps

• Conduct a Larger AquaSel Demonstration Project: – Validate the process at a larger scale utilizing

one full-size AquaSel module – Sized for 100 gpm (typical size of Aquasel

module) – 1/16 of a full-scale 2.3 mgd plant

• Demonstration Project will: – Include full scale components – Refine the design and sizing of the

precipitator – Utilize the same EDR stack as a full-scale plant – Confirm the AquaSel process has been

optimized for a full-scale plant – Validate preliminary estimates for operating

costs

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Summary and Conclusions

Importance of EMWD’s Multi-benefit Brackish Water Desalination Program

• Supply - creates a drought-proof sustainable potable water source to meet growth: – Will provide over 17,500 AF/year to serve 35,000 households – Is cost effective and competitive with alternative supplies

• Groundwater basin management and regional salt balance: – Protects potable basins from brackish intrusion – Net salt export – Sustains recycled water program through source water salinity

reduction • Technology optimization for brine recovery:

– Brine discharge minimization and recovery

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Contact Information

Paul D. Jones II General Manager (951) 928-3777 Ext. 6130 Email: [email protected]