CHED 250

Brewer Lake, a 1200-acre water impoundment in central Arkansas, supplies drinking water to Conway, Arkansas and surrounding towns.  Recently, extensive gas-well drilling has begun in the Fayetteville shale in northern and central Arkansas, including the 36-square-mile watershed of Brewer Lake.  Students of the Department of Chemistry, Hendrix College, Conway, Arkansas are currently sampling and analyzing the lake's water to determine if the run-off is changing the water quality.  In this study ion chromatography is being used to measure the following ions: Na⁺, K⁺, Ca²⁺, Mg²⁺, NH₄⁺, F^-, Cl^-, NO₃^-, SO₄^2- and PO₄^3-. The instrument is a Dionyx Model 1500 with auto sampler.  A CS12 column is used for the positive ions, an AS9-HC column for negative ions.  Turbidity, pH, temperature, conductivity, and dissolved oxygen are also being monitored.  Results of the analyses will be presented.