Transcript Newark Desalination Facility - North Bay Watershed Association

Newark Desalination
Facility
ACWD Service Area
C
Well Fields
Union City
Hetch-Hetchy (SFPUC)
South Bay Aqueduct
(DWR)
San Francisco Bay
Fremont
San
Francisco
Oakland
Fremont
Location Map
San Jose
Walnut
Creek
Newark
0
0.5
miles
1
Water Treatment
Plants
ACWD Water Supply
Planning

ACWD Integrated Resources
Planning Study (1995) identified key
issues for ACWD:
Dry year water supply reliability
 System production capacity
 Water 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



Water Production


Provides new source of production to
distribution system
Water Quality



New source of supply
Firm source of supply
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 membranes
performed well and will meet WQ
Objectives

RO Concentrate met NPDES discharge
requirements
2001 – Designs Finalized
ACWD Service Area
C
Union City
San Francisco Bay
CEDAR
WELLFIELD
DARVON
WELLFIELD
Fremont
Desal Facility
DESALINATION
FACILITY
$12.2 M
Well Upgrades
Newark
$ 1.3 M
Supply and
Discharge Pipelines $ 6.7 M
0
0.5
miles
1
Total : $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
Labor
18%
Chemicals
11%
Membrane
Replacement
6%
Power
65%
Power Cost - $1,026,564
Chemical Cost - $166,375
Labor Cost - $278,775
Amortized Membrane Replacement Cost - $88,647
Summary – What Have We Learned?

Desalination provides ACWD cost-effective
local supply




Most challenging aspects included:



Improved water quality
Public acceptance – favorably received
Cost comparable with other supplies
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




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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
1
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 – 40.1
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



Finished Water Quality


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TDS <100 mg/l
Hardness < 10 mg/l
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