1 | emwd.org

Brackish Desalination – Water Supply Planning for Resiliency and GrowthJoe Mouawad, P.E.

November 17, 2016

2 | emwd.org

EMWD 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)

• EMWD Representative –Randy Record, Chairman

4 | emwd.org

Products and Services

Fresh Water: 145,000 accounts

• Imported Water

• Hemet Water Filtration Plant

• Perris Water Filtration Plant

• Menifee Desalter

• Perris I Desalter

• Perris II Desalter (design)

• Groundwater Wells

Wastewater: 237,000 accounts

4 wastewater treatment plants

• Capacity: 70 MGD

• Currently treating: 45 MGD

Recycled Water:

• EMWD treats 100% of wastewater generated

• 100% of effluent is reused for RW application

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EMWD’s Water Supply Portfolio

• Balanced Portfolio of Supplies with 54% of total supplies from diversified local sources; 46% imported

• 100% beneficial reuse of recycled water within service area; fully subscribed

• Two brackish desalters in operation - ~7,400 acre feet production in CY 2015 of potable water from otherwise unusable groundwater

• Groundwater production from an adjudicated/managed basin with replenishment resumed in CY 2016

Imported Water46%

Ground-water12%

Desalter6%

Recycled Water36%

Calendar Year 2015123,087 AF

Source: EMWD 2015 Urban Water Management Plan

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Brackish Desalination Program

• Objectives:

– Develop substantial unused brackish (>1,000 mg/l) groundwater in service area that receives sub-surface recharge

– Protect adjacent groundwater resources from salinity intrusion

– Achieve net salt balance relative to imported water supplies

– Utilize available brine disposal options and advance recovery technologies

– Implement timely and cost effective expansion projects

7 | emwd.org

Salinity Management

GroundwaterManagement Zones –

Ambient Water Qualities (AWQ)

GMZ AWQ

(mg/L)

Canyon 340

San Jacinto Upper Pressure 350

San Jacinto Lower Pressure 800

Lakeview 860

Hemet North 860

Perris North 760

Hemet South 940

Menifee 2030

Perris South 2400

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EMWD’s Desalination Program Components

• Groundwater Wells

• Desalter Feed Pipelines

• Treatment Facilities

– Menifee and Perris I Desalters

– Perris II Desalter (future)

• Brine Disposal

– Inland Empire Brine Line

– On-site recovery (future)

9 | emwd.org

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

• Treatment Facility – 3.6 MGD with Reverse Osmosis

• Production Facilities – four wells with combined capacity of 3,000 gpm

• Brine Disposal

• Desalter feed pipelines

• Finished water pipeline

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Brackish Desalination Supply Costs

$979 - $1,073

$250

$1,015 - $1,235

$401

$2,014 - $2,257

$1,200 - $1,400

$0

$500

$1,000

$1,500

$2,000

$2,500

Imported waterfrom MWD

GroundwaterWells

DesalinatedGroundwater

Recycled Water OceanDesalination

Indirect PotableReuse

EMWD Supplies Alternative Supplies

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Importance of Brine Concentration

• Menifee and Perris I Desalters reject 25% of treated flow as brine (75% recovery rate)

– Typical of reverse brackish source water reverse osmosis systems

• Generated Brine Volume:

– Menifee Desalter 0.9 MGD

– Perris I Desalter 1.4 MGD

2.3 MGD

• Loss of Valuable Water Resources:

– Presently – 2,500 AF/year

– Future – 4,000 AF/year

• Brine Management Objectives:

– Maximize available water resources

– Reduce disposal costs

14 | emwd.org

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 has 5.9 MGD pipeline capacity and is currently using about 3.5 MGD

– Cost for O&M $1.05 M/yr

• Cost for purchased capacity:

– Pipeline capacity $3.75 Million/MG

– Treatment and disposal capacity $8.6 million/MG

EMWD Desalters

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Perris/Menifee Desalters Operational Costs

Category Cost

Labor and staffing $85/AF

Chemicals $45/AF

Energy $45/AF

Materials and services $35/AF

Brine disposal charges $200/AF

Wells $95/AF

Average cost $505/AF

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EMWD’s 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 (1,890 hours of run time)

• Peer review by U.S. Bureau of Reclamation

18 | emwd.org

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

– May be used as potable water if desalted

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 Aquaselmodule)

– 1/16 of a full-scale 2.3 mgd plant

• This 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

20 | emwd.org

Summary and Conclusions

Advantages of EMWD Brackish Water Desalination Program

• Creates local potable water source to meet growth:

– Will provide over 14,600 AF/year to serve 30,000 households

• Reduces dependence on imported water

• Is cost effective and competitive with alternative supplies

• Supports regional salinity management and offset objectives

• Sustains recycled water program through source water salinity reduction

• Provides opportunities for expansion through technology

– Brine minimization and recovery

21 | emwd.org

Contact Information

Joe Mouawad, P.E.Senior Director of EngineeringPhone Number (951) 928-3777 Ext. 4463

Email: mouawadj@emwd.org