An adaptive management approach to improve water quality at a model dairy farm in Vermont, USA

Shelburne Farms is a non-profit environmental education center and working dairy farm located in Shelburne, Vermont, on the shores of Lake Champlain. Ecological and recreational functions of Lake Champlain have been increasingly threatened by high inputs of contaminants such as phosphorus, a high proportion of which is contributed by non-point sources including agriculture. Concerns about agricultural pollution motivated Shelburne Farms to set an example of good stewardship by applying an adaptive management process to investigate and improve water quality. The purpose of this paper is to describe both the process and outcomes as they evolved through a collaborative effort between Shelburne Farms, local stakeholders, and researchers at the University of Vermont. The adaptive management process included: (1) assessing conditions based on four years of water quality monitoring, (2) identifying and prioritizing potential solutions, (3) implementing a solution by installing a stormwater treatment system, (4) evaluating start-up performance of the treatment system, and (5) adjusting the strategy based on the results. Pre-implementation monitoring indicated that unacceptable levels of phosphorus and Escherichia coli entered the lake in runoff during storm events and that the dairy barnyard area was a significant contributor of pollutants. The stormwater treatment system, installed to treat runoff from the dairy barnyard area, reduced TSS and P concentrations within the first few months of operation on average by 25% and 43%, respectively, across all storm events. E. coli concentrations were highly variable with a mean reduction of 1% and median reduction of 78%. The adaptive management process was effective in engaging stakeholders, securing funds to implement solutions, and providing research results to inform future work.