Bacteriological Water Quality in Vermont Agricultural Watersheds Undergoing Land Treatment

ABSTRACT

Bacteria are often important indicators of nonpoint source water pollution. Runoff from farmland and agricultural activities such as animal waste management, feedlots, and grazing are the principal sources of bacteria to surface waters. Fecal coliform and fecal streptococcus levels have been monitored in four Vermont agricultural watersheds for eight years as part of the LaPlatte River Watershed Project. This project is a long-term monitoring program designed to evaluate the effects of implementing best management practices on water quality. Bacterial densities recorded in the monitored streams and in runoff from specific agricultural practices are reported. While levels of fecal streptococci in the streams have declined significantly since implementing land treatments, bacterial densities continue to exceed water quality criteria 20 to 30 percent of the time, particularly in summer. Bacterial densities in the streams appear related to agricultural activities within their watersheds such as corn production, pasturing, and animal density.