Vic Kelson (presenter), Rhett Moore, and Bruce Duhe, Layne Christensen Company
For about 50 years, brackish water has been identified in the “1500-foot sand” aquifer in Baton Rouge, LA, moving northward from the Baton Rouge Fault. The intrusion of the brackish water has occurred as a result of long-term pumping of wells in the aquifer within and north of the City. In 2012-2013, Layne Christensen, Owen and White, and Baton Rouge Water Company collaborated on the design and construction of a “scavenger well couple”, a pair of wells that achieve in-situ separation of the brackish fraction of water at the bottom of the aquifer from the overlying fresh water. The scavenger well couple is not intended to remedy the brackish intrusion. It has been constructed as a means for protecting the viability of the Lula groundwater pumping station, which lies north of the scavenger.
This talk focuses on the field study and groundwater flow modeling that was conducted in support of the scavenger couple’s design. We will describe the science of how the couple works, in detail, and the design trade-offs that were central issues for the construction of the couple. We will also demonstrate the advantages of the two-well scavenger methodology to other approaches, such as small “skimming” wells or horizontal wells, for long-term water development in the Southern Hills Aquifer System.