Five-year microbial and chemical assessment of the Blue Marsh Watershed in Reading, Pennsylvania

• High concentrations of nitrates and phosphates were found in the Blue Marsh Watershed. • Escherichia coli and Enterococcus spp. counts exceeded EPA limits over 52 and 83 percent of the times, respectively, tested. • Anthropogenic actions may raise pathogenic bacteria and toxic algae concentrations in the Blue Marsh Watershed. Recreational, agricultural, and industrial utilizations of areas surrounding waterways provide opportunities for collecting chemical and pollutant runoff, which influence the chemical makeup of the waterways and connecting watersheds. Human activities within watersheds can result in conditions that enable pathogenic microorganisms to thrive and allow unique microbial communities to emerge. The study area consisted of three locations at the Blue. Marsh Watershed in Reading, Pennsylvania, with different surrounding land use and anthropogenic activities. The study areas were monitored monthly during the five-year project to assess seasonal variations in chemical levels and microbial count changes. Chemical testing included inorganic nitrates, inorganic phosphates, and dissolved oxygen. Additional microbial testing included monthly counts for Escherichia coli and Enterococcus spp. to assess potential pathogenic microbial populations. On most occasions, chemical analyses found nitrate and phosphate concentrations above natural environmental levels. During the five years, Escherichia coli and Enterococcus spp. concentrations were above the EPA recreational water recommendations 52% and 83% of the time, respectively. These results suggest that recreational, agricultural, and industrial utilization of surrounding waterways may influence chemical and microbial characteristics, including pathogenic microorganisms in the Blue Marsh Watershed.