Transcript Nonpotable Strategy Project RPMT Briefing

Colorado Springs’ ASR
Program
Presented by Cortney Brand
Western Water Workshop, Gunnison, CO
July 28, 2005
Outline
 Colorado Springs’ Water
System
 Long-Term Water Supply Plan
 Denver Basin Aquifers
 Benefits of ASR
 ASR Operational Concept
 Feasibility Investigation
 Long-Term Testing
 Next Steps
Rampart Reservoir
Colorado Springs’ Water System
 Serve water to approx. 410,000 people
 97% surface water (primarily snowmelt)
 3% alluvial and bedrock groundwater
 Extensive network of diversions, tunnels, reservoirs,
pipelines and canals
 Can deliver 110,000 AF/yr from 200 miles away
 Current demands of 80-90 KAF/yr, projected to be 180
KAF/yr by 2040
 includes existing and planned DSM programs
Supply Systems
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Colorado Springs
FVA Pipeline
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Local (1800’s – present)
Blue R./S. Platte (50’s)
Homestake (60’s)
Fry-Ark (60’s)
Twin Lakes (70’s)
Colorado Canal Exchange (80’s)
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Long-Term Water Supply Plan
 New major delivery system – Southern
Delivery System (SDS)
43-mile, 66-inch pipeline from Arkansas River
Delivery capacity of 78 MGD
Online by around 2011-12
 Bridge gap by:
Local water system improvements
Nonpotable water development & distribution
Groundwater development & ASR
Denver Basin Aquifers
 Extensive sedimentary bedrock
aquifer system
 Non-renewable
 Underlies ~7,000 mi2 area (40% of
Denver
Basin
Colorado Springs)
 Relatively low transmissivities and
well yields
 Colorado Springs has 15 Denver
Basin wells
 Delivery capacity of 3,600 AF/yr
 Used for supplemental potable
supply and irrigation (parks, etc.)
Colorado
Springs
Why Pursue ASR?
 Unique (for Front Range) combination of surface and
groundwater supplies and infrastructure
 Additional water storage capacity
 Leverage investment in groundwater supply infrastructure
 Use off-peak capacity in treatment plants and pipelines
 Bank water for future dry years
 Improve sustainability of Denver Basin groundwater
 Diversify water supply portfolio (risk mitigation)
ASR Operational Concept
October – April (Inject/Store)
Proactively Deliver from Reservoir Storage
(make space to capture spills)
Treat
Pipe to wells
Inject into aquifers
ASR Operational Concept
May – September (recover)
Disinfect
Recover Water
Deliver to Tanks
ASR Feasibility Investigation
 Conducted Fall of ’04
 Injection/recovery testing at two wells
 Water sampling & analysis
 Geochemical modeling
 ASR water availability analysis
Used supply system Operations & Yield model to
quantify “spills”
 Conceptual plan for implementing ASR
ASR Testing Results
 Arapahoe Well
 Injection rate of 500 gpm
(pumping rate of 600+ gpm)
 No water quality concerns
 Denver Well
 Injection rate of 75 gpm
(pumping rate of 75+ gpm)
 Potential recovered water
quality concerns
 Need pH adjustment
Northgate Tank Site
ASR Water Availability
80%
Percent of Time Available
70%
Short-term goal (5 yrs)
60%
Ultimate goal (10 yrs)
50%
2005
2010
2015
40%
2020
2030
30%
2040
20%
10%
0%
1,000
2,000
3,000
4,000
5,000
10,000 15,000 20,000 25,000 30,000 35,000
Amount Available (ac-ft)
Long-Term Testing
 Started in July – complete in December
 Objectives
 Determine sustainable, long-term injection rates
 Verify water quality
 Determine backwash frequencies
 Arapahoe Well
• 500 gpm
• 3 months injection
• 2+ months recovery
 Denver Well
• 50-75 gpm
• pH adjustment
• 2 injection/recovery cycles
Next Steps
“Crawl, Walk, Run”
1. Evaluate long-term testing results
2. Operate Northgate ASR facility in 2006
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Will recovered water need to be re-treated?
Can we maintain injection rates?
Is the system easy to operate?
Develop and implement water accounting practices
3. Retrofit additional wells
4. Work toward goal of 2-3 KAF/yr capacity by 2010
Questions?