The city of College Station relies solely on groundwater wells for its water supply. As the population grows, water demands are increasing and the aquifer is experiencing drawdown. The groundwater conservation district may mandate pumping restrictions if drawdown thresholds are reached. To plan for potential future limits on well pumping and meet demand, the city is considering alternative water supply options like aquifer storage and recovery, direct potable reuse, brackish groundwater desalination, and surface water from the Brazos River. Cost estimates and feasibility issues are discussed for each option.

1. City of College Station
Water Supply Alternatives
September 11, 2017
City Council Workshop

2. Background
• CS water supply is 100% Groundwater wells
• We have 7 deep Simsboro wells and 2 shallow wells
– Another deep Simsboro well will be drilled this Fall
– Have land for one more deep Simsboro well
• Well Permits restricted by pump rate and Annual production
• Future water supplies are adequate to meet demands
• See following charts

5. Potential Future Pumping Reductions
• Well Permits regulated: BV Groundwater Conservation District
– Can mandate pumping restrictions if aquifer conditions warrant
• Aquifer health determined by Drawdown since 2000
– Drawdown is measured by Static Water Level
• Maximum Drawdown is about to be set at 295’ for Simsboro
• Benchmark was set in 2000, so far we’ve seen 28’ drawdown
– At this rate, the max is reached in 168 years
– Growing population and Exports will accelerate this rate
• BVGCD has established drawdown triggers to activate cutbacks
• We must identify alternative water supplies:
– Deal with potential future well pumping cutbacks
– Determine best source of water supply for growth

6. Water Supply Options – based on 6 MGD
1. ASR – Aquifer Storage & Recovery
a. Take treated wastewater effluent, treat it again to drinking water quality, inject it
into an aquifer, and pump it out when needed.
b. Ballpark construction cost: $154 million
c. Operational costs: High
d. Feasibility: Very good.
2. DPR – Direct Potable Reuse
a. Take treated wastewater effluent, treat it again to drinking water quality, and put
it right back into the potable water system.
b. Ballpark construction cost: $119 million
c. Operational costs: High
d. Feasibility: Very good. Must overcome “yuck factor”

7. Water Supply Options – based on 6 MGD
3. Desalination – Brackish Groundwater
a. Drill wells into brackish region of Simsboro aquifer, treat the water to remove
excess salt, then add to water system.
b. Ballpark construction cost: $58 million
c. Operational costs: High
d. Feasibility: Questionable, since these wells would require permits from BVGCD
and would be subject to the same cutbacks as our potable wells.
4. Surface Water – Brazos River Supply
a. Get a permit from the Brazos River Authority to pump water from the Brazos
River, treat the water to drinking water quality, then add to water system.
b. Ballpark construction cost: $46 million
c. Operational costs: Moderate
d. Feasibility: Await outcome of legal challenges to BRA’s System Operations Permit
to see whether this option is feasible.
e. Note: Gibbons Creek reservoir is a possible option as well.