1. Outline of Presentation
Definition of Aquifer Storage and Recovery (ASR)
Why ASR?
Joint Powers Water Board
ASR Well 9
ASR Pilot Testing Results
Current ASR Status

2. Definition of ASR
ASR involves storing treated drinking water underground in times when water is available for later withdrawal to meet peak, drought, or emergency demands

3. Confining Layer Confining Layer
ASR Wells Can Provide an Alternative Water Supply
Confining
Layer
Native
Ground
Water
Native
Ground
Water
Buffer
Zone
Stored
Water
Stored
Water
Buffer
Zone
Target Storage Volume
Confining Layer

4. ASR Applications Peak shaving for water treatment
Seasonal, long-term or emergency storage
Maintain distribution system flow/pressure
Other ASR applications (maintaining wetlands, controlling saltwater intrusion)

5. Joint Powers
Joint Powers Water Board – Albertville, Hanover, St. Michael, Minnesota
Seven Wells (4 drift, 3 Mt. Simon), 6,500 gpm firm capacity
10 MGD WTP
8 MGD Max Day, 2.5 MGD Avg. Day
14 MGD max day demand projected in 2020

6. ASR Site
ASR Site

7. ASR Site

8. Joint Powers Well 9 Mt. Simon Well – drilled in 2006
504’ deep
30” casing to 197’, 24” casing to 447’
Open hole from 447’ to 504’
Mt. Simon is deep, confined aquifer
150 hp submersible motor, 1,000 gpm pump
3” ASR recharge pipe

9. Well 9 – Background Chemistry
Iron – 1.2 mg/L
Manganese – 0.27 mg/L
Radium 226/228 – 9 pCi/L
Gross Alpha 19 pCi/L

10. Joint Powers Well 9

11. Joint Powers Wellhouse 9

12. Joint Powers Wellhouse 9

13. Joint Powers Wellhouse 9

14. Joint Powers Wellhouse 9

15. Wellhouse 9 Site

16. ASR Permitting MDH Variances Pilot Cycles 1 & 2
Additional Monitoring Wells (TW-5, TW-6)
Continuous Monitoring
Pilot Cycle 3 – Second Variance
Distribution Sampling
Class V Injection Well Permit
Draft Permit was issued in Sept. 2008
Minor Modification issued for Pilot Cycle 3 in 2010
Major Modification issued for full scale testing in 2012

17. Pilot Test Cycles 1 & 2 Pilot Test Cycle 1 – Feb. 2009
Recharged 361, gpm
Stored one day
Recovered 1,300,000 gallons to waste
Pilot Test Cycle 2 – Feb. 2009
Recharged 6,090,000 gallons
Stored one month
Recovered 9,400,000 gallons to waste
Extensive Sampling

18. Pilot Test Cycle 3
Started Recharge on May 26, 2010, concluded on October 11, 2010
310 gpm recharge
62,700,000 gallons recharged
Started Recovery on January 6, 2011, concluded on February 21, 2011
Recovery rate 700-1,000 gpm continuous, to distribution system
Recovered 52,000,000 gallons

19. Pilot Test Cycle 3
Samples collected during recharge, storage, recovery – Fe, Mn, radionuclides daily
Aesthetic water quality good
Chemical Feed
No fluoride necessary until 50% recovery
2 mg/L chlorine ( gpm)

20. Annual Sampling Requirements
Collect background samples from Well 9, TW-6, distribution system
Collect monthly injection samples, 95% TW-6, Well 9
Collect 5%, 30%, 60%, 100% recovery samples
Distribution sampling for THMs, HAA5

21. Reporting Requirements
Monitor water levels continuously (TW-3, TW-4, TW-5, TW-6, Well 9)
Monitor injection pressure, volumes
Monthly injection reports to EPA, MDH
Annual summary report

22. Current Status Currently in fifth year of full scale ASR operation.
2012: Recharged 50 MG, Recovered 40 MG
2013: Recharged 58 MG, Recovered 48 MG
2014: Recharged 90 MG, Recovered 80 MG
2015: Recharged 70 MG, Recovered 60 MG
2016: Started recharge in Nov. 2015, on track to recharge 90 MG by June 2016.

23. ASR Cost/Benefit Analysis
Compare capital cost of new treatment plant or expansion to cost of ASR well
Need metering and monitoring equipment (wellhouse) with ASR well
Sampling costs
Still have the cost of treating water and pumping
More regulatory hurdles with ASR