Hydrochemical Characterization of Brines and Identification of Brine Contamination in Aquifersa

Abstract

ABSTRACTHydrochemical investigations of aquifer contamination by brine are usually approached using conventional graphical methods (i.e. Stiff, Piper, and Schoeller diagrams). While these methods may be used successfully to identify brine in distinction from other contaminants (e.g., road deicing agents) in ground water, they are unsuccessful in differentiating between brine contaminants from different stratigraphic origins. We present a methodology to be employed in hydrochemical investigations of suspected brine contamination, which incorporates the use of select ionic ratios [Ca:Mg, Na:Ca, Na;Mg, Na:Cl, K:Cl, K:Na, Mg:K, Ca:K, Cl:Mg, Cl:Ca, and (Ca + Mg):(Na + K)] in discriminant analysis and modified graphical methods. The method is tested by applying it to an area of known brine contamination in northeastern Ohio. The results of the test indicate that the method is successful in identifying brine as a contaminant in ground water and in identifying the stratigraphic origin of the brine. This method, when combined with information obtained from drilling reports, can be used to suggest a point source for the brine contamination.