Water quality assessment following the implementation of BMPs in the Grout Brook sub-watershed, Skaneateles, New york

Nutrients, sediments and pathogens associated with agricultural activities often lead to the impairment of surface waters. The effectiveness of BMPs in improving water quality within the Grout Brook sub-watershed was assessed by monitoring bacterial and nutrient levels from June to November 2006. In addition to measuring flow rate and five water quality parameters in-situ, bi-weekly grab samples were collected from nineteen sites along the entire reach of Grout Brook. In 2007, an exercise to determine the impact of cattle crossing on downstream bacterial concentrations was also conducted. Total coliform and E. coli concentrations exceeded EPA MCLs at all sites, however nutrient levels were low, with ortho-phosphate levels being the only nutrient to exceed EPA MCL. The intense impact of cattle crossing on bacterial levels was found to be temporary. There were no significant differences in nutrient levels between the current and previous year.;Keywords. Total coliform, E. coli, attenuation, best management practice, nitrates, orthophosphate, maximum contaminant level, regression model.