City of Kerrville Aquifer Storage and Recovery System; A Drought Management Tool

City of Kerrville Aquifer Storage City of Kerrville Aquifer Storage and Recovery System; A and Recovery System; A

Drought Management ToolDrought Management Tool

Stuart Barron/City of Kerrville, TexasStuart Barron/City of Kerrville, TexasJames Dwyer, P.E. /CH2M HILL, Austin, TexasJames Dwyer, P.E. /CH2M HILL, Austin, Texas

Texas Innovative Water 2010October 11-12, 2010October 11-12, 2010San Antonio, TexasSan Antonio, Texas

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Presentation OutlinePresentation Outline

• ASR ConceptsASR Concepts– Supply & DemandSupply & Demand– Typical ApplicationsTypical Applications– RegulationsRegulations

• Kerrville ASRKerrville ASR– History & PhasingHistory & Phasing– HydrogeologyHydrogeology– TechnologyTechnology– Current StatusCurrent Status

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Projected Demand

Water Supply and DemandWater Supply and Demand• Southern and Western USSouthern and Western US

– High Population and Demand GrowthHigh Population and Demand Growth– Stressing Existing Water SuppliesStressing Existing Water Supplies

• Climate ChangeClimate Change– Changing Precipitation DistributionsChanging Precipitation Distributions– More Extreme EventsMore Extreme Events– Longer DroughtsLonger Droughts– Warmer TemperaturesWarmer Temperatures

Projected Supply

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Options for StorageOptions for Storage• Surface ReservoirsSurface Reservoirs

– Historical solution to enhanced availabilityHistorical solution to enhanced availability

– Regulatory, economic, political obstacles to new Regulatory, economic, political obstacles to new constructionconstruction

– Costs have increasedCosts have increased

– Lead times increased 10 to 20 yearsLead times increased 10 to 20 years

• Aquifer Storage and RecoveryAquifer Storage and Recovery

– Generally maintains quality of stored waterGenerally maintains quality of stored water

– Can reduce required peak capacity of WTPCan reduce required peak capacity of WTP

– Reduced environmental impactReduced environmental impact

– Fewer obstacles, faster, more flexible implementationFewer obstacles, faster, more flexible implementation

– Control of stored water an issueControl of stored water an issue

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ASR Project ConceptASR Project Concept• Traditionally Annual Demand FluctuationsTraditionally Annual Demand Fluctuations

• Multi-year Storage for Long-Term Drought ProtectionMulti-year Storage for Long-Term Drought Protection

• Optimization of Available SupplyOptimization of Available Supply

Injection Cycle

J F M MA DJ J A S O N

Months

Monthly DemandAnnual Average DemandASR

Recovery

ASRStorage

ASR Storage

Recovery Cycle

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Typical ASR ElementsTypical ASR Elements

Raw Water WithdrawalRaw Water Withdrawal

Treated Treated Water StorageWater Storage

Water Treatment Plant

ASR Well

TreatedWater

Raw Water StorageRaw Water Storage

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Texas Regulatory Texas Regulatory ConsiderationsConsiderations

• Surface Water RightsSurface Water Rights

• Groundwater LawGroundwater Law

• Underground Injection ControlUnderground Injection Control

• Public Drinking Water RulesPublic Drinking Water Rules

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Texas Surface Water RightsTexas Surface Water Rights

• Surface water belongs to the StateSurface water belongs to the State

• State grants the right to use the State grants the right to use the waterwater

• Appropriated water rightsAppropriated water rights– How muchHow much– WhenWhen– For what purposeFor what purpose

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Texas Groundwater LawTexas Groundwater Law

• Rule of CaptureRule of Capture• Groundwater is the private property of the Land Groundwater is the private property of the Land

OwnerOwner• Texas Supreme Court 1904Texas Supreme Court 1904

– Houston & T.C. Ry Co. v. East 81 S.W.279Houston & T.C. Ry Co. v. East 81 S.W.279– Reaffirmed in Sipriano v. Great Spring Waters of Reaffirmed in Sipriano v. Great Spring Waters of

America, Inc. 1 S.W. 3d 75America, Inc. 1 S.W. 3d 75 (Ozarka Case) (Ozarka Case)

• LimitationsLimitations– May not pump to maliciously harm neighborMay not pump to maliciously harm neighbor– May not use in wasteful mannerMay not use in wasteful manner– May not use in negligent manner so as to cause land to May not use in negligent manner so as to cause land to

subside/settlesubside/settle

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Groundwater Engineering and Groundwater Engineering and ScienceScience

• ““Because the existence, origin, Because the existence, origin, movement, and course of such waters, movement, and course of such waters, and the causes which govern and direct and the causes which govern and direct their movements, are so secret, occult, their movements, are so secret, occult, and concealed that an attempt to and concealed that an attempt to administer any set of legal rules in administer any set of legal rules in respect to them would be involved in respect to them would be involved in hopeless uncertainty, and would, hopeless uncertainty, and would, therefore, be practically impossible.”therefore, be practically impossible.”

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Groundwater Conservation Groundwater Conservation DistrictsDistricts• Local Management of Groundwater Local Management of Groundwater

ResourcesResources– climatic conditionsclimatic conditions– water use patternswater use patterns– growth projectionsgrowth projections– aquifer characteristicsaquifer characteristics

• Comprehensive Management PlansComprehensive Management Plans• Associated RulesAssociated Rules

– Well spacingWell spacing– Production limitationsProduction limitations– Exporting water outside the districtExporting water outside the district

• Permitting and Data CollectionPermitting and Data Collection

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Class V Injection WellsClass V Injection Wells• Texas Commission on Environmental Quality UICTexas Commission on Environmental Quality UIC• Miscellaneous group that does not fit into the other Miscellaneous group that does not fit into the other

four injection well classes.four injection well classes.• Underground Source of Drinking WaterUnderground Source of Drinking Water

– Supplies any public water systemSupplies any public water system– Contains sufficient water <10,000 mg/l TDSContains sufficient water <10,000 mg/l TDS– Not an exempt aquiferNot an exempt aquifer

• Generally inject non-hazardous fluids into or above Generally inject non-hazardous fluids into or above an underground source of drinking wateran underground source of drinking water

• Authorized by ruleAuthorized by rule– Usually do not need permitUsually do not need permit– Must submit inventory informationMust submit inventory information

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Public Drinking WaterPublic Drinking Water

• Texas Commission on Environmental Texas Commission on Environmental QualityQuality

• Required offsets from potential Required offsets from potential pollutionpollution

• Minimum construction standardsMinimum construction standards

• Plan review processPlan review process

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Project Project LocationLocation

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Kerrville ASR HistoryKerrville ASR History

• Dependence on Groundwater until 1980 - Dependence on Groundwater until 1980 - Declining Trinity aquifer levelDeclining Trinity aquifer level

• Late 1980’s - Considered Guadalupe River Water Late 1980’s - Considered Guadalupe River Water Treatment Plant expansion with off-channel Treatment Plant expansion with off-channel reservoirreservoir

• Alternative - store treated surface water from the Alternative - store treated surface water from the Guadalupe River undergroundGuadalupe River underground– Phase 1 Feasibility 1988Phase 1 Feasibility 1988

– Phase 2 Full-Scale Testing, ASR-1 1992Phase 2 Full-Scale Testing, ASR-1 1992

– ASR-2 Construction 2001, operational in 2002ASR-2 Construction 2001, operational in 2002

– ASR-3 Under construction, planned completion 2011ASR-3 Under construction, planned completion 2011

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Recent Kerrville Water Recent Kerrville Water StatisticsStatistics• 80%-90% of Water from Guadalupe River80%-90% of Water from Guadalupe River

– 3 permits total 5922 ac-ft/yr (1930 MG)3 permits total 5922 ac-ft/yr (1930 MG)

• Balance from Trinity Aquifer WellsBalance from Trinity Aquifer Wells– 5.55 mgd (6.15 MGD with Emergency Well)5.55 mgd (6.15 MGD with Emergency Well)

• 5.2 mgd Conventional WTP Capacity5.2 mgd Conventional WTP Capacity

• 1.0 mgd Membrane Expansion1.0 mgd Membrane Expansion

• Total Annual Raw Water DemandTotal Annual Raw Water Demand– approx. 1,400 MG/yrapprox. 1,400 MG/yr

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Geologic Geologic SectionSectionNorthNorth SouthSouth

1800

1600

1400

1200

1000

Guadalupe RiverGuadalupe River

ApproximateApproximateGround SurfaceGround Surface

Upper Member ofGlen Rose Limestone

Lower Member ofGlen Rose Limestone

Hensel Sand

Hammett Shale(Confining Layer)

Hosston and SligoFormations

Cow Creek Limestone

Pre-Cretaceous Rock

Hosston-SligoPotentiometric Surface

ASR-1ASR-1

Upper Member ofGlen Rose Limestone

Lower Member ofGlen Rose Limestone

Hensel Sand

Hammett Shale (Pine Island)

Hosston and SligoFormations

12” Open Hole

Injection Tubes

FE

WTPClearwell

FE

ToDistribution

RechargeRechargeLineLine

RecoveryRecoveryLineLine

Pump

495’

125’

Submersible Pump

RecoveryRecovery RechargeRecharge

16” T&C SteelCasing

MonitoringMonitoringWellsWellsASR-1ASR-1

Cow Creek Limestone

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Schematic of ASR Schematic of ASR 11

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ASR 1 OperationASR 1 Operation

• Treated water from Stadium Drive HSPSTreated water from Stadium Drive HSPS

• 200 to 700 gpm through recharge tubes200 to 700 gpm through recharge tubes

• Monthly backflushing during recharge to Monthly backflushing during recharge to restore capacityrestore capacity

• Recovered water disinfected at wellheadRecovered water disinfected at wellhead

• 1000 to 600 gpm rate1000 to 600 gpm rate

• Initial recovery to storm sewerInitial recovery to storm sewer

• Switch to clearwell for distributionSwitch to clearwell for distribution

2020

2121

2222

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Schematic of ASR Schematic of ASR 22

FE

Chlorine FeedChlorine Feed To/FromDistribution

Upper Member ofGlen Rose Limestone

Lower Member ofGlen Rose Limestone

Hensel Sand

Hammett Shale (Pine Island)

Hosston and SligoFormations

Cow Creek Limestone

EllenburgerEllenburger

13 3/8”T&C Casing

495’

75’ 20” Open Hole

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Operation of ASR 2Operation of ASR 2

• Treated water from distribution systemTreated water from distribution system

• Up to 400 gpm (through the pump)Up to 400 gpm (through the pump)

• Monthly backflushing to restore capacityMonthly backflushing to restore capacity

• Recovered water disinfected at wellheadRecovered water disinfected at wellhead

• 600 gpm Rate600 gpm Rate

• Initial recovery to storm sewerInitial recovery to storm sewer

• Delivered directly into distribution Delivered directly into distribution systemsystem

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2626

2727

2828

2929

3030

3131

3232

281 MG

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Technical IssuesTechnical Issues• Application FeasibilityApplication Feasibility

– System Water BalanceSystem Water Balance– HydrogeologyHydrogeology– Capital and Operations CostsCapital and Operations Costs– IntegrationIntegration– Test WellsTest Wells

• ASR DesignASR Design– WellWell– WellheadWellhead– WellfieldWellfield

• TestingTesting– During ConstructionDuring Construction– Post ConstructionPost Construction– Long-Term MonitoringLong-Term Monitoring

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ASR Cycle TestingASR Cycle Testing• Multiple Cycles of Injection and RecoveryMultiple Cycles of Injection and Recovery

• Evaluate Hydraulic PerformanceEvaluate Hydraulic Performance– Injection of non-native water Injection of non-native water

can alter the borehole near the wellcan alter the borehole near the well

• Evaluate Recovery EfficiencyEvaluate Recovery Efficiency– Water Chemistry InteractionsWater Chemistry Interactions

and Mixing and Mixing

• Data CollectionData Collection– Flow RateFlow Rate– Water LevelsWater Levels– Water QualityWater Quality

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Recovery EfficiencyRecovery Efficiency

• ImportanceImportance– Loss of Injected WaterLoss of Injected Water– Increase in Treatment Increase in Treatment

RequirementsRequirements

• FactorsFactors– MixingMixing– Chemical ReactionsChemical Reactions– Regional Groundwater Gradients Regional Groundwater Gradients

• DeterminationDetermination– Conservative Chemical Conservative Chemical

ConstituentsConstituents– Native vs. Stored WaterNative vs. Stored Water

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SummarySummary• Kerrville was one of the first communities Kerrville was one of the first communities

to utilize ASRto utilize ASR

• Significant savings over surface Significant savings over surface reservoir/WTP expansionreservoir/WTP expansion

• ASR can be implemented at different ASR can be implemented at different scales and in phasesscales and in phases

• Currently, Kerrville has banked a large Currently, Kerrville has banked a large supply of treated water to protect against supply of treated water to protect against a long term droughta long term drought

• Design of ASR 3 is underwayDesign of ASR 3 is underway

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Questions?Questions?