Proceedings of the 2022 Mississippi Water Resources Conference

Year: 2022 Authors: Chaux L.C., Ramirez Avila J.J., Achury S.O., Czarnecki J., Schauwecker T.

Livestock production is a predominant economic activity in the United States (US). However, it is also considered one of the agricultural activities that contributes to pollution of the nation's waters. It's currently estimated that around 55% of the assessed US streams have been impaired by sediments and nutrients coming from non-point sources via overland flow. A study was established to assess the spatiotemporal variation in water quality under baseflow conditions in the mainstream flowing through the MSU Joey Bearden Dairy Research Center. Water quality monitoring consisted of biweekly grab sampling and in-situ testing (dissolved oxygen, pH, turbidity, specific conductivity, total dissolved solids) from July 2019 to March 2020. Laboratory analysis of water samples included assessment of total suspended solids (TSS), total phosphorus (TP), total nitrogen (TN) and coliforms concentration. Water quality parameters were contrasted with state and national recommended water quality criteria. Results suggest the study reach is unable to meet the nutrient requirements for the assigned designated use. Mean concentrations of TP were 10 and 6 times higher than the nutrient criteria during the summer and winter months, respectively, while TN concentrations were 4 and 2 times higher. Overall, colony forming units of Escherichia coli exceeded in up to 19 times the corresponding criteria. In addition to the impairment on water quality, field observations have evidenced the unrestricted access of animals to the stream has negatively affected stream hydrology (i.e. higher runoff due to compacted soils) and geomorphology (i.e. streambank erosion). Monitoring efforts after implementing a 30-ft riparian zone buffer will be contrasted to evaluate the BMP effectiveness.