Challenge. Assessment of available water supplies, source water quality, and permitting requirements for siting of two power plants

Solution. INTERA applied expertise with the surface and groundwater characteristics at both sites in conjunction with our experience working with groundwater conservation districts to define the most suitable water sources, with respect to water quality, quantity, and permitting requirements, for each proposed power plant site. Surface water was not a viable option at either of the sites. The target raw water production rates were 2,500 gallons per minute (average) and 4,100 gallons per minute (peak) for each of the sites, which were located over two different aquifer systems. The Fannin County site overlies the Northern Trinity and Woodbine aquifers in north Texas, while the Neches County site overlies the Carrizo-Wilcox Aquifer—the more productive of the two aquifer systems. INTERA reviewed relevant literature regarding hydraulic properties of the aquifers and collected and analyzed pump test and specific capacity test data in the areas of the two proposed sites. Groundwater quality was assessed through groundwater samples and geophysical logs (gross quality). We provided guidance in obtaining the appropriate permits for the water supply wells and performed local-scale drawdown analyses with a multi-layer analytic element code (TTIM) that enabled us to evaluate drawdowns at both the water supply wells and other nearby wells that could potentially be impacted. After our assessment confirmed that adequate supplies exist at each site, we also provided optimal well layouts to establish the costs associated with developing the water supplies.