Newark Desalination Facility

San Francisco Bay

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Location Map

Fremont

ACWD Service Area

Hetch-Hetchy (SFPUC)

South Bay Aqueduct (DWR)

Fremont

Well Fields

Water Treatment Plants

ACWD Water Supply Planning

ACWD Integrated Resources Planning Study (1995) identified key issues for ACWD:Dry year water supply reliabilitySystem production capacityWater quality (hardness)

IRP Recommended Strategy and Implementation Status

Item Status

Water Conservation All cost-effective BMPs are being implemented

Off-site Water Storage

150,000 AF of groundwater banking secured at Semitropic (1996, 2001)

Enhanced Local

Conjunctive Use

Quarry Lakes recharge pits rehabilitation completed (1996)

Recycled Water Joint ACWD/Union Sanitary District feasibility studies completed

Brackish GW Desalination

Phase 1 (5 MGD) facility in operation

(2003)

Niles Cone Groundwater Basin and Aquifer Reclamation Program

Niles Cone Groundwater Basin

Brackish Groundwater Desalination Concept

Brackish Groundwater Desalination Benefits

Water Supply New source of supply Firm source of supply

Water Production Provides new source of production to

distribution system Water Quality

High quality water Helps meet district’s hardness goals

Reliability of Local Control Provides water source west of Hayward

Fault Does not rely on outside sources

1998 - Pilot Tests Performed

Findings

ARP water has low membrane fouling potential & requires minimal pretreatment

Low pressure membranesperformed well and will meet WQ Objectives

RO Concentrate met NPDES discharge requirements

San Francisco Bay

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ACWD Service Area

DESALINATION FACILITY

CEDAR WELLFIELD

DARVON WELLFIELD

2001 – Designs Finalized

Desal Facility $12.2 MDesal Facility $12.2 M

Well Upgrades $ 1.3 MWell Upgrades $ 1.3 M

Supply and Supply and Discharge Pipelines $ 6.7 MDischarge Pipelines $ 6.7 M

Total : $20.2 MTotal : $20.2 M

Concentrate Discharge

Final Discharge Location Flood control channel

discharges to San Francisco Bay (approximately 2500 ft from Desal, 20,000 ft from San Francisco Bay)

Discharge Monitoring is conducted regularly to ensure that the concentrate stream is not negatively impacting the environment

Projected Annual Operating Cost: $ 241/Ac-Ft

Chemicals 11% Power

65%

Membrane Replacement

6%Labor 18%

Power Cost - $1,026,564Chemical Cost - $166,375Labor Cost - $278,775Amortized Membrane Replacement Cost - $88,647

Summary – What Have We Learned?

Desalination provides ACWD cost-effective local supply Improved water quality Public acceptance – favorably received Cost comparable with other supplies

Most challenging aspects included: Discharge permit Construction in an urbanized area

Future challenges include: Regulatory changes regarding discharge Future energy costs uncertain

End of Presentation

NPDES Permit Requirements for Desal

Conduct Self-Monitoring Program:On a monthly basis:

• Perform Acute Toxicity Testing on Concentrate– static renewal bioassay using 2 test species: three-spine stickleback and either rainbow trout or fathead minnow.

• Sample Concentrate for - Total Dissolved Solids, Dissolved Oxygen, Chlorides, Conductivity, pH, Temperature, Salinity and Total Metals (i.e., Arsenic, Cadmium, Chromium, Copper, Lead, Magnesium, Mercury, Nickel, Selenium, Silver and Zinc).

Flood Control Channel Discharge Issues

Concentrate Water Quality• Salinity• Trace Metal Concentrations

Habitat Impacts• Sensitive Species• Vegetation

Permit Acquisition• Regional Water Quality Control Board NPDES

Permit to Discharge• Calif Dept of Fish & Game Streambed Alteration

Permit to Construct Outfall

Permit Acquisition Approach

Identify Major Stakeholders and their concerns California Regional Water Control Board (RWQCB) United States Fish and Wildlife Services (USFWS) California Department of Fish and Game (CDF)

Conduct feasibility & technical studies (i.e., pilot work & water quality analysis)

Conduct vegetative biotic surveys to confirm habitat species

Projected Concentrate Discharge Water Quality

Specific Constituents of Concern

RWQCB

Fresh Water Quality Objectives (ug/L)2

Projected Concentrate Discharge (ug/L)

Selenium 5 2.8 – 4.6

Copper 38.7 19.9 – 32.8

Chromium VI 11 ND1

Nickel 509 3.3 – 5.5

Zinc 343 24.2 – 40.11 Non Detect (Chromium VI is not naturally occurring and typically present when total chromium values are elevated. Projected total chromium = 14.9 -24.6 ug/l)2 Calculated values assuming a hardness = 400 mg/l

Water Quality Objectives RO Permeate (Potable) Water Quality

TDS <100 mg/l Hardness < 10 mg/l

Finished Water Quality Hardness <150 mg/l Non-corrosive Good Tasting Water

Concentrate Water Quality pH 6-9 Non-toxic Meet NPDES Permit Requirements

Future Related Projects Wellfield Treatment Facility

Purpose: Demineralize well water and reblend w/ well and SFPUC Water

Impact: Lower hardness, improve protection and operating flexibility

Date: 2006

Newark Desal Facility Expansion Purpose: Additional production; blended with well

water Impact: Lower, more uniform hardness, increase

reliability Date: 2009