GEOCHEMICAL AND BACTERIAL CHANGES ALONG THE BUFFALO NATIONAL RIVER

The Buffalo River runs approximately 150 miles from Newton County, Arkansas to Baxter County eventually joining the White River. The Buffalo National River is the one of the last free flowing rivers in the continental U.S. with a rich cultural and political history surrounding it. The geology of the area can be characterized by karst and its many caves, depressions, and sinkholes found along the river, which makes it more susceptible to groundwater pollution. An increase in animal production in the area is also a concern for increased nitrate and phosphate, along with fertilizer runoff from agricultural areas. The purpose of this study was to determine the geochemical and bacterial changes along the Buffalo River from human and environmental influences. Samples were collected at several different locations along the river along with parameters such as pH, conductivity, salinity, and temperature during several trips in the summer and fall of 2017. Water samples were analyzed for cations and anions by IC, trace metals by ICPMS, and Escherichia coli with agar colony counts.

The results reveal a general increase in Ca, Na, sulfate, and Sr as the river flows downstream with higher concentrations in the Big Creek tributary. Chloride and Mg also increased in concentration as the river flowed downstream, but with lower concentrations in the Big Creek tributary. Other anions, such as nitrate and phosphate, were analyzed, but concentrations were below detection levels. The trace elements Li, B, and Ba show a general decrease in concentrations downstream, which could be a result of more dilution of anthropogenic water discharge. The results of some of the cations, anions, and trace elements are all factors of the geology (i.e. high Ca and Sr from limestone). No constituents were above EPA standards. However, higher concentrations in June can be attributed to lower water level and discharge. The Escherichia coli results had the highest concentrations at the Pruitt campground, which is one of the most visited campgrounds in the watershed located just a few miles from the city of Jasper. September overall, had higher colony counts, which can be attributed to lower water levels and higher surface water temperatures.