With the growing number of ethanol plants planned and under construction, water use and environmental concerns associated with associated water discharge are increasing.   Water regulation authorities and the public are taking notice and starting to pressure the industry to evaluate existing and new water conservation measures.

Ethanol plants will use water in their process, boiler and cooling tower makeup and in their water treatment units such as reverse osmosis, softeners and multi-media filtration.  Evaporation loss in the cooling towers is the largest area of water use at an ethanol facility.  

Ethanol siting evaluations should include site-specific hydrogeologic studies that consist of an evaluation of existing literature, discussions with local/regional groundwater regulators, and area drillers.  If this initial study indicates good potential for groundwater production, a field investigation is completed to characterize local hydrogeologic conditions and theoretical aquifer yield.  The field investigation phase can include the use of surface and downhole geophysics, surface lineament studies, placement of exploratory soil borings, and installation of test/observation wells.

Long-term aquifer response to ground water withdrawal can only be determined from monitoring a carefully designed network of observation wells, including potential surface water gauging stations, during ethanol facility operation.  Long term groundwater elevation monitoring may be completed through manual or automated groundwater monitoring technologies.
 
Moving forward, the ethanol industry must continue to look at existing and new water treatment technologies to reduce their water consumption and eliminate or minimize their discharge to surface or ground water.  Use of wastewater treatment plant discharges, synergistic uses with adjacent industries, geothermal technologies, and emerging water treatment technologies should be considered as water conservation options for all future ethanol facilities.