GROUNDWATER TRANSFER & INJECTION: PROGRESS TOWARD A MANAGED AQUIFER RECHARGE OPTION FOR SUSTAINABLE GROUNDWATER SUPPLY

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1 GROUNDWATER TRANSFER & INJECTION: PROGRESS TOWARD A MANAGED AQUIFER RECHARGE OPTION FOR SUSTAINABLE GROUNDWATER SUPPLY J.R. Rigby, Ph.D. Research Hydrologist National Sedimentation Laboratory USDA-ARS, Oxford, MS

2 Recharge from:

3 What is Managed Aquifer Recharge (MAR)? Purposeful recharge of water to an aquifer unit for subsequent recovery Surface infiltration management Infiltration basins Stream Weirs Artificial Recharge (Injection) Aquifer storage and recovery (ASR) Aquifer storage, transfer and recovery (ASTR) Bank filtration + Transfer + Injection

4 Groundwater Injection

5 River-Aquifer Interactions Aquifer Supplies Water to River River Recharges Aquifer

6 Riverbank Filtration

7 Bank Filtration Transfer & Injection Abstraction Wells/ Stream Capture Injection Wells ~10mi RIVER Avg flow ~1500 cfs 75,000 gpm/ 170 cfs 120,000 ac-ft/yr x10 x10 Water quality from bank filtration uncertain, but recharge rate relatively high with moderate footprint

8 Example Well Fields

9 What we don t know Will the river supply enough water through the riverbed? Is the water pumped near the river channel of sufficient quality for injection? How should we design and site a groundwater transfer and injection project for best operation?

10 Groundwater Transfer & Injection Project (GTIP) Pilot Study

11 GTIP Pilot Study 1 well along the river, 1 injection well 1-2 mi transfer between wells Proof of concept Data collection on operational efficiency and design considerations Design and cost analysis of full-scale GTIP

12 GTIP Pilot Study - status Determination of possible pilot study sites Permitting requirements Funding Preliminary hydrologic and geophysical data collection Study design

13 Preliminary hydrologic and geophysical data collection Aquifer Study at Money, MS

14 What we don t know Will the river supply enough water through the riverbed? Is the water pumped near the river channel of sufficient quality for injection? How should we design and site a groundwater transfer and injection project for best operation?

15 Aquifer Study Money, MS DESCRIPTION Pumping test using existing irrigation well along banks of Tallahatchie River, consisting of Observation well network Geophysical (resistivity) surveys RATIONALE Use observation well hydraulic response and water chemistry changes to determine stream bed conductance and aquifer parameters USES Constrain stream bed conductance for Tallahatchie River in MERAS for regional modeling Provide inputs for small-scale, high-resolution engineering model for abstraction-injection hydraulics along river

16 Aquifer Study Money, MS Observation Well Schematic 50m 25m 300m 100m 10m ~100m Observation Well Irrigation Well 5m Hunt, B. (1999) Unsteady stream depletion from ground water pumping. Ground Water 37(1):98-102

17 Aquifer Study - Money MS Geophysical Survey GPS Resistivity Profile

18 Aquifer Study - Money MS 6 deep resistivity profiles Max depth of investigation is about 225 feet below land surface Used to develop a 2D image the aquifer and confining units

19 Aquifer Study - Money MS North South Aquifer ~100ft thickness Confining Unit PRELIMINARY DATA Subject to revision Not for distribution

20 Aquifer Study - Money MS 1 irrigation well 2400 gpm 3 days pumping Observation 21 observation Well Configuration wells (preliminary) 2 sides of the river 5m-600m

21 Pump Test Feb 8-10

22 Groundwater Levels PUMPING BEGINS DRAWDOWN PUMPING ENDS RECOVERY PASSIVE/AMBIENT PRELIMINARY RESULTS

23 Observations ~350 ft from Irrigation Well PRELIMINARY RESULTS

24 Initial results Very rapid drawdown and recovery More drawdown on the east side of the river than expected Less drawdown near the pumping well than expected 1 Ft of drawdown measured ~2000 ft away Three phases to analyze: drawdown, recovery, ambient Wells remain instrumented during the growing season

25 Next step Money Study Modeling & Interpretation 1D to 3D incorporating geophysics (w/ NCCHE) Collecting growing-season water levels Collect geophysics on east side of the river Continued planning for a Pilot Project

26 Acknowledgements John Bush and Annette Morgan USGS: Wade Kress, Roland Tollett, et al. YMD: Mark Stiles, Board, Dave Kelly Scott Flynn (USDA-ARS) MDEQ Delta Council, Delta FARM Special thanks to Scott, Roland and Dave for long hours and creative problem solving

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