Total concentrations of ammonium (NH{sub 4}{sup 1}) have been found to exceed the State of Wyoming ground water quality standard for Class 1 aquifers near Torrington, Wyoming. The cause of the NH{sub 4}{sup 1} contamination is thought to be associated with fertilizer use and/or the leaching of organics into the ground water from impoundments holding wastes from sugar beet processing. This type of contamination could be expected from other industrial processes, including those associated with the use of fossil fuels. In an initial step in understanding and solving the ground water contamination problem, Western Research Institute (WRI) conducted a laboratory investigation to understand the aquifer system as it relates to the chemistry of NH{sub 4}{sup 1} as it moves through the aquifer material. The data collected during the attenuation tests do provide an indication that the attenuation of NH{sub 4}{sup 1} in the ground water system will occur. In addition, the results show the redox condition of the site and the possible chemical reactions that are influencing the ground water quality.