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American Society of Farm Managers & Rural Appraisers
Kevin Morrison, P.G.Project Coordinator – Desalination Engineering
Brackish Groundwater Desalination Program Update
October 2, 2014
October 2, 2014
Brackish Groundwater Desalination Program UpdatePage 2
Outline• Background
• Treatment Process
• Program Progress
• Program Cost
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Background
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SAWS Water Supply - 2014No Cutbacks
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What is Brackish Groundwater?• Brackish groundwater
contains total dissolved solids (TDS) greater than 1,000 milligrams per liter – Fresh: 0 – 1,000 mg/l– Edwards: 350 – 400 mg/l – Brackish: 1,000 – 10,000
mg/l– Saline: greater than 10,000
mg/l– Seawater: greater than
35,000 mg/l
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Brackish Groundwater Desalination Program UpdatePage 6
Why Brackish Desalination?
• Untapped resource
• Large volumes of available brackish water– Estimated over 2.7 billion
acre-feet
• Resource close to San Antonio
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Brackish Groundwater Desalination Program UpdatePage 7
Feasibility - 2006
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Carrizo – Wilcox Cross Section
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Production WellsInitial Test
WellsProduction Wells
(8)Depth 1250 - 2660 1205 - 1770
Production Rate (gpm) 800-1000 800 -1100
Total Dissolved Solids (mg/L)
1437 1346
Iron (mg/L) 0.233 0.314Silica (mg/L) 18.8 18.5
Water Chemistry
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Brackish Groundwater Desalination Program UpdatePage 10
Membrane Pilot Testing
• Receive TCEQ capacity rating and permit
• Test membranes from three manufacturers
• Test pre-treatment/post treatment options– “Open System” vs. “Closed System”
• Additional Investigations– Concentrate Pipe Loop Study
– Air Leak Testing
– System fouling trend and membrane autopsy SAWS Membrane Pilot Test Unit
Pilot Testing Goals
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Brackish Groundwater Desalination Program UpdatePage 11
Current BGD Program • Phase I (2016)
o 12 MGD or 13,440 Acre-feet/yr
• Phase II (2021)o 12 MGD or 13,440
Acre-feet/yr
• Phase III (2026)o 6 MGD or 6,720 Acre-
feet/yr
• Totalo 30 MGD or 33,600
Acre feet/yr
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Treatment Process
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Diagram by Osmonics, Inc.
Reverse Osmosis Membrane Construction
RO Treatment
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RO Treatment
Acid
CF
AS
Calcite Contactor,Degasification,Sodium hydroxide
Product
WellConcentrate Disposal
Raw Water Blending
RO
Concentrate
Pre-treatment
Primary treatment
Post treatment
AS: Anti-scalent CF: Cartridge Filter
13
.11
MG
D2
MG
D
10 MGD
1.1
1 M
GD
11
.11
MG
D
12 MGD
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Brackish Groundwater Desalination Program UpdatePage 15
What is Concentrate/Brine• Reverse osmosis treatment plant produces
two products– 90% permeate (30-60 mg/L TDS)– 10% concentrate (~15,000 mg/L TDS)
• Concentrate stream requires disposal
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Concentrate DisposalOptions Considered
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Class I Test Injection WellPerforated Versus Open Hole Completion
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Injection Zone
~ 860 ft. Thick
Confining Zone
~ 2,360 ft.Thick
Production Zone ~ 600 ft.
Thick
GeorgetownEdwards &
Upper Glen RoseLimestone
Midway Shale
AnacachoLimestone
Navarro Clay
Wilcox Sand(Brackish Water)
Upper Wilcox Clay
Carrizo Sand(Fresh Water)
Austin Chalk
Eagle Ford Shale, Buda
Limestone, & Del Rio Clay
Well Construction
Injection Tubing
Retrievable Packer
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Class I Test Injection Well
• Total Project Cost: $4.83M• Cost Per Linear Foot: $958
Project Costs
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Class I Test Injection WellInjection Well Results• Depth: 5,000 – 5,300 ft
• Injection Zone Edwards Limestone Upper Glen Rose Limestone
• Native Edwards water salinity ~ 90,000 mg/L TDS
• 450 gpm Injection Rate
• Two Injection Wells required for BGD Phase I (about 1.1 MGD)
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Program Progress
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20132012
Conceptual Design
Pre-Construction
Design
2015 20162014
Program Completion October
2016
Construction Management Services
Construction
Commi-ssion
Commi-ssion Warranty
Warranty
2017 2018Program Manager
(PM)
Construction Manager at Risk
(CMAR)
GMP Board AwardMarch 2014
CMAR Process• Process allows:
– Contractor’s input in the design– Engineer’s involvement in construction planning– Qualification based selection– Guaranteed maximum price (GMP)– Pursue SAWS SMWB goals
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Brackish Groundwater Desalination Program UpdatePage 23
Program Components• 12 - Production Wells
• 2 – Injection Wells
• Reverse Osmosis Treatment Plant
• Pipelines
• SCADA and Electrical system
• Security
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Activities Completed• Design Completed
– Wells– Conveyance– RO Treatment Plant– Electrical / SCADA– Security
• Construction and Guaranteed Maximum Price approved by SAWS Board in March
• Construction Manager at Risk in the procurement phase
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Current ActivityTreatment Plant Earthwork – Jun. 21, 2014
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Current ActivityTreatment Plant Earthwork – Sept. 9, 2014
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Program Cost
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Cost
• Total estimated construction cost:
$192.66 million
• $/AF: $1,177 / AF
• Construction in Progress
• Completion - October 2016
Phase I
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Brackish Groundwater Desalination Program UpdatePage 29
Questions?
American Society of Farm Managers & Rural Appraisers
Kevin Morrison, P.G.Project Coordinator – Desalination Engineering
Brackish Groundwater Desalination Program Update
October 2, 2014
