SEASONAL WATER STORAGE AND REPLENISHMENT OF A FRACTURED GRANITE AQUIFER USING ASR WELLS

Transcription

1 SEASONAL WATER STORAGE AND REPLENISHMENT OF A FRACTURED GRANITE AQUIFER USING ASR WELLS Mario R. Lluria; Phillip M. Paski; Gary G. Small HydroSystems, Incorporated Phoenix, Arizona USA

2 Presentation Contents Managed Aquifer Recharge Development in Arizona The Payson M.A.R. Project Water Resources Availability and Challenges Water Supply Alternatives and Solutions Hydrogeologic Framework Regional Geology Local Geology Hydrogeology Hydrogeochemistry Water Chemistry of the Cragin Reservoir Spring and Groundwater Chemistry Impacts of Blending Reservoir Water and Groundwater Geophysical Studies Evaluation of A.S.R. A.S.R. Well Field Operation Conclusions

3 M.A.R. in Arizona Main Reason For Its Progress 1980 Groundwater Management Act Central Arizona Project (CAP) Aqueduct Excess CAP Water Storage Issue Water Reclamation and Storage Insufficient Direct Use Intensive Aquifer Use

4 M.A.R. in Arizona Development Phases Phase I Experimental Studies Phase II Demonstration Projects Phase III Large Storage Capacity Water- Spreading Facilities Phase IV Intermediate to Small Storage Capacity Facilities

5 Water-Spreading Facilities GRUSP Development In-channel basins in the Salt River Recharge capacity 100,000 ac-ft/yr (123,300,000 m 3 /yr) Near SRP and CAP water infrastructure Started operation in 1994 Total cost $2.2M

6 Water Spreading Facilities GRUSP and NAUSP W White Tank Mountains Agua Fria River NAUSP Salt River GRUSP E McDowell Mountains Red Mountains UAU MAU LAU UAU MAU LAU West Salt River Valley Basin East Salt River Valley Basin

7 M.A.R. in Arizona Water-Spreading vs Well Recharge Capacity Water-Spreading ASR Well Vadose Zone Well 5, ,000 ac-ft/yr (6,165, ,950,000 m 3 /yr) < 5,000 ac-ft/d (<6,165,000 m 3 /d) Water Source CAP, RW, S&V, Mixed RW, CAP RW Unit Cost ($/ac-ft) Very low High Intermediate 1,000 15,000 ac-ft/yr (1,233,000 18,495,000 m 3 /yr) Number of Facilities

8 TOWN OF PAYSON AQUIFER STORAGE AND RECOVERY PROJECT

9 Water Resources and Challenges Groundwater is currently the sole source of supply The aquifer is a fractured granite Individual well production ranges from liters/second 42 production wells meet daily peak and annual demand of 3,108,000 m 3 /yr Extreme drought pressures these limited groundwater supplies Long-term sustainability requires additional water supplies

10 Water Supply Solution Arizona Water Settlements Act of 2004 with the Completion of the Cragin Pipeline Project (Blue Ridge). Diversifies the supply portfolio by adding 3,700,500 m 3 /year. The Cragin Project entails a ~15 mile pipeline, a combo hydro-generation/water treatment plant facility, and in-town improvements. Annual allocation will be delivered over 9-months due to weather conditions. Innovative conjunctive use strategies which bring groundwater, surface water, and reclaimed water sources together, can lead Payson to water supply sustainability, even within our drought sensitive environment.

11 Water Supply Solution Groundwater production areas which were once over pumped are now planned for seasonal and long-term storage recovery of surface water through Aquifer Storage and Recovery Wells ASR The use of ASR will meet seasonal needs while also helping to restore previously depleted groundwater areas ASR storage capacity in the aquifer is estimated at 15,420,000 m 3 but seasonal recovery of over 7,000 acre-ft is anticipated between When 100% full the aquifer is estimated to hold a minimum of 27,200,000 m 3 of recoverable water Over 15 years, approximately 6,800,000 m 3 of injected surface water may remain in the aquifer to augment natural recharge. Therefore, pre-pumping aquifer conditions should be restored via ASR wells and natural recharge!

12 Hydrogeologic Framework REGIONAL GEOLOGY Rock Units Age Tectonic Events Gravel, sands, silts Quaternary-Recent None Rim Gravel and Limestone Tertiary-Quaternary Late B. and R. Basalt flows Tertiary (Cenozoic) Late B. and R. Colorado Plateau Section: Limestones, conglomerates, sandstones, shales Felsic to mafic volcanic and intrusive rocks; metasediments, metavolcanics Cambrian-Permian (Paleozoic) Early to Middle Proterozoic ( Ma) (Precambrian) B. and R. Laramide Jurassic Faulting B. and R. Laramide Jurassic Faulting

13 Composite, General Stratigraphic Section for the Study Area. Looking west along the Diamond Rim Fault across the northern part of the Verde Graben, west of Payson

14 Geologic Cross-Section Displaying Water Level Elevation From the Mogollon Rim to the East Verde River

15 ARIZONA TECTONIC EVENTS pc FOLDING 1.6 b.y pc RIFTING JURASSIC FAULTING LARAMIDE FOLDING, THRUSTING PLUTONISM CORE COMPLEX MID-MIOCENE FAULTING B AND R FAULTING 1.1 b.y 150 m.y. 65 m.y. 25 m.y. 14 m.y. 6 m.y. TIME ---Summary of the tectonic events in Arizona and their approximate mean time of occurrence. The middle Cenzoic orogeny includes the core complex formation and the detachment-listric faulting.

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17 Hydrogeologic Framework HYDROGEOLOGY

18 The C-Aquifer, Mogollon Rim North of Payson, Arizona

19 The RMX-Aquifer, Payson Airport Road, Arizona

20 Fractured System of the Payson Granite. Road cut in Payson, Arizona. Weathered Payson Granite. Road cut in Payson, Arizona.

21 Hydrogeochemistry Source Surface Water C.C. Cragin (Blue Ridge) Reservoir SRP Groundwater Capacity: 18.5 Mm 3, ; Runoff snowmelt and rain from the Colorado Plateau. Type: Calcium Bicarbonate; TDS ~ 42 mg/l; ph ~ 7.3; LI ~-1.8 Shallow/Local Aquifer (Payson Granite X Aquifer) Type: Calcium Bicarbonate TDS: mg/l; ph ~ 7.2 Deep/Regional Aquifer (Payson Granite X Aquifer) Type: Calcium-Bicarbonate TDS: mg/l; ph ~ 7.8 Local + Regional Aquifer (Payson X Aquifer) Type: Calcium Bicarbonate TDS ~ 266 mg/l; ph ~ 7.7; Ca ~ 47mg/l; Fe ~0.056 mg/l; As<0.001mg/l Regional X Aquifer (Gibson Creek Batholith) Higher TDS, Na S0 4 (sulphide veins) Blending SW and GW. In the Aquifer (Payson Granite) Geochemical Modeling: Dissolution of CaC03 and CaS04 and minor precipitation of Fe(OH)3.

22 The C.C. Cragin Reservoir Located in the Colorado Plateau, north of Payson, Arizona. It is a unit of the SRP surface water storage system.

23 Water Chemistry Difference Piper Diagram Indicating Water Chemistry Difference Between Regional Groundwater Aquifers and Local Recharge Town of Payson, Arizona

24 Chemical Variability of Spring, Surface and Well Waters Chemical Variability of Spring, Surface and Well Waters as Shown by Stiff Diagrams (Colors indicate regional aquifer contribution and shapes generally vary according to amount of local recharge)

25 Geophysical Studies NSAMT Survey. Zonge Engineering Crew, Payson, Arizona

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27 ASR Evaluation The Town of Payson ASR System and Operation 2006 Tested 5 existing wells Recharge capacity 81.6 l/s Tested 8 existing wells Recharge capacity: l/s 13 wells recharge capacity: 20,000 m 3 /d ASR Planned Operation Will use excess WTP water after municipal and surface storage demand is met. ASR Well Field: 4 Base Load Wells 20 cm (8 ) steel casing with O.P. Recharge continuously 4 On-Call Wells 25 cm (10 ) steel casing with F.C.V. Recharge on demand only Computerized (SCADA) Fully Automated Recharge Operation With Manual Control Option.

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29 Town of Payson ASR Well Testing

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32 With Renewable Surface Water Use Fully Maximized Via ASR and Conjunctive Use Payson Achieves True Water Resources Sustainability Town of Payson Future ( ) Water Resources Portfolio: Diversified

33 Do ASR Wells Really Work in Granite? The Payson Water Department, in collaboration with HydroSystems Inc., have tested about a dozen wells. It can be done! Payson will be one of the first to use ASR in a fracture granite aquifer. We have proven a recharge capacity of more than 231 l/s or about 20,000 m 3 /d Exceeded project goal by more than 100%