saws - development of brackish groundwater desalination project
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Development of Brackish Groundwater Desalination Project: SAWS Twin Oaks Brackish Groundwater Desalination ProgramTRANSCRIPT
TWCA 2014 Mid-Year Conference
W. John Seifert, Jr., P.E.LBG-Guyton Associates
Kevin Morrison, P.G.San Antonio Water System
Development of Brackish Groundwater Desalination Project: SAWS Twin Oaks Brackish Groundwater
Desalination Program
June 12, 2014
June 12, 2014
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Topics
• Groundwater Hydrology • Groundwater Supply Development• Program Update
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What is Brackish Groundwater?
• Practical Definition: Brackish groundwater contains from 1,000 to 10,000 mg/L TDS
Fresh Brackish Saline Fresh Slightly-saline Moderately-saline Very-saline
1,000 mg/L 3,000 mg/L 10,000 mg/L
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Why Consider Brackish Groundwater?
• By 2060– Population will increase by 82% to 46.3 million– Demand will increase by 22%– Municipal demand will increase 71%– Supply (existing sources) decrease 10%– Advances in treatment technology
– Data from TWDB 2012 State Water Plan
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Carrizo-Wilcox
Gulf Coast
Hueco-Mesilla Bolsons
Major Aquifers
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Carrizo-Wilcox Aquifer
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Gulf Coast Aquifer
(Wells >500 ft deep)
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Aquifers with Substantial Amounts of Brackish Groundwater
• Carrizo-WilcoxInterbedded sand, silt and clay
• Gulf CoastInterbedded sand, silt and clay
• Hueco-Messilla BolsonsSilt, sand and gravel
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Favorable Conditions for a Brackish Groundwater Project• Water quantity adequate• Water quality acceptable
– Total dissolved solids content slightly saline to moderately saline
• Resource located in reasonable proximity to demand• Regulatory environment reasonable• RO Concentrate Management can be cost contained• Project effects are acceptable
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Carrizo-Wilcox Aquifer
- Strive for locations with
greater areal extent of resource
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Geologic Description of an Area
• Electric Log Data Point
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Carrizo-Wilcox and Gulf Coast AquifersBrackish Groundwater Resource Below Fresh Groundwater
Land Surface
Increasing
Depth
Brackish Water Sand(Yellow)
Freshwater Sand(Blue)
Clay(Brown)
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Wilcox Brackish Sands in Gonzales CountyF. Passmore #1
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GroundwaterSupply
Development
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Sequence of Supply Development
• Evaluate desk top data• Outline area for test drilling if needed• Perform drilling and water quality testing• Design wells and wellfield with appropriate well
spacing• Construct and test wells and evaluate water quality
data• Equip wells and construct water conveyance
infrastructure
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Screen Installation And Gravel Packing
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Large Capacity Brackish Water Production Well
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Production Well TestingObtain data on aquifer
productivity,
can be used for
groundwater flow modeling
Obtain water quality data
Collect data regarding
well efficiency
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Program Update
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Program General Information
• Source Water– Lower Wilcox Formation– 12 Production Wells – Avg. depth 1,600 ft.
• Treatment Process– Reverse Osmosis – 90% Recovery
• Concentrate Disposal– Deep Well Injection – 5,000 ft. depth– Two injection wells required for Phase I
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Program Components
• Production Wells
• Conveyance System (Pipelines)
• Reverse Osmosis Treatment Plant
• Injection Wells
• Electrical / SCADA
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SAWS BGD Program• Phase I (2016)
– 12 MGD or 13,440 Acre-feet/yr.
• Phase II (2021)– 12 MGD or 13,440 Acre-feet/yr.
• Phase III (2026)– 6 MGD or 6,720 Acre-feet/yr.
• Total– 30 MGD or 33,600 Acre-feet/yr.
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Lessons Learned from Past Projects
• Program Manager not having control over designers
• Low bid contractor may not be best qualified
• No contractor’s input in the design document preparation
• Claims, litigation and delays
• Change orders
• Lack of cooperation
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• Designer Engineers are under the contract of the Program Manager
• Sub-contractors are selected based on qualifications and experience under the Construction Manager At Risk (CMAR) procurement
• CMAR contractor were involved in the design phase
• Performance Incentive proposed
Procurement Plan
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Program Structure
- 4 Design Teams
- 20 Design Sub-Consultants
- 17 SMWB Firms
- 21 Local Firms
SAWS
Construction Manager at Risk (CMAR) Zachry Parsons Water
Resources JV
Program Manager Black & Veatch Corp.
Sub-ContractorsDesign Sub-Consultants
- 12 Construction Packages
- Multiple Subcontractors
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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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Guaranteed Maximum Price
• CMAR will publicly bid each construction package and recommend most qualified best value sub-contractor
• The payment to CMAR will be based on actual cost of construction not to exceed the GMP
• Should the actual cost be lower than the GMP, the difference will be a credit to SAWS
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Shared Performance Incentives• Maximum of $250,000 to Program Manager
• Maximum of $750,000 to CMAR
• Objective Parameters:• Budget• Completion Schedule• Change Control
• Subjective Parameters:• Partnering, Quality of service, Conflict Resolution,
Timely Responses
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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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Production vs. Disposal
Land Surface
GeorgetownEdwards &
Upper Glen RoseLimestone
TD = 5,040 ft.
Midway Shale
AnacachoLimestone
Navarro Clay
Not to Scale
TD = 1,600 ft.
Production Well Injection Well
Confining Zone
~2,360 ft. Thick
Wilcox Sand(Brackish Water)
Upper Wilcox Clay
Eagle Ford Shale, Buda
Limestone, & Del Rio Clay
Austin Chalk
Carrizo Sand(Fresh Water)
Injection Zone
~ 860 ft. Thick
Production Zone
~ 600 ft. Thick
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Remaining Work for Phase I
• Additional four production wells
• Additional injection well
• Reverse Osmosis treatment plant
• Pipelines
• SCADA and Electrical system
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Construction Package Procurement
Work Package
DescriptionSAWS Approval of
CMAR Recommendation
1 Enabling (Silt Fencing / Site Fencing) May-142 Site Work May-143 Foundation May-144 Electrical / SCADA May-145 Water Treatment Plant Jun-146 Pipelines Jun-147 Access Roads Jun-148 Well Fit Out Jul-149 Production Wells Jul-14
10 Injection Wells Jul-1411 Landscaping Dec-1412 Security
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Cost
• Phase I total estimated construction cost is $192.66 million
• $/AF: $1,177 / AF
Phase I
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Questions?
TWCA 2014 Mid-Year Conference
W. John Seifert, Jr., P.E.LBG-Guyton Associates
Kevin Morrison, P.G.San Antonio Water System
Development of Brackish Groundwater Desalination Project: SAWS Twin Oaks Brackish Groundwater
Desalination Program
June 12, 2014