Challenge. Develop new brackish water supply well(s) needed to increase water supply from 1,500 gallons per minute (gpm) to 4,000 gpm to support expansion of natural gas storage capacity by constructing two additional storage caverns within the Jefferson Island salt dome

Solution. INTERA provided siting and design of production and monitoring wells; design, performance, and analysis of aquifer tests; and spatial prediction of the water level (potentiometric surface) drawdown over the planned 5-year production period. Prior to installing a full-sized production well, test and observation wells were installed for initial water quality sampling and aquifer testing. INTERA performed and analyzed a step-drawdown test and a 24-hour constant-rate test (pumping rate of 183 gpm) on the test well that showed the hydraulic conductivity and specific storage of the lower sand unit was sufficient to provide the water needed for expansion of facility operations. We also assisted in the design and testing (step-drawdown and constant-rate test at 1,700 gpm) of the full-size production well. Based on the results of the production well aquifer testing, INTERA developed a matrix of estimated potentiometric surface drawdowns at distance over time for several different scenarios including a range of production rates and interference effects assuming the concurrent production from a second well. The results of our efforts helped provide JISH with additional groundwater that not only meets the needs for expanding gas storage capacity, but does so in a manner that is minimizing any negative impacts to the surrounding agricultural industry.