In Vermont and across the Lake Champlain Basin, the extent of tile drainage systems and their
potential impacts on water quality have not been adequately assessed. A previous study by
Stone Environmental (Stone) for the Lake Champlain Basin Program in the Jewett Brook
watershed in Franklin County (Braun et al. 2019) revealed that subsurface drainage systems in
agricultural fields can discharge significant quantities of phosphorus (P). This project adds to the
previous work by measuring nutrient and sediment concentrations and loads in tile drainage
water in a second agricultural area, Addison County, and comparing these values with nutrient
and sediment concentrations and loads measured in tile drains in the Jewett Brook watershed.

Development of a treatment train facility to remove phosphorus from Jewett Brook prior to
discharge to St. Albans Bay has the potential to accelerate water quality improvements in St.
Albans Bay. Jewett Brook has chronically elevated concentrations of phosphorus. Implementing
a treatment train facility on Jewett Brook would involve withdrawing, treating, and releasing a
portion of the streamflow. This facility could extend ongoing agency nutrient reduction programs
focused on implementation of agricultural conservation practices in the St. Albans Bay
watershed and bring the St. Albans Bay phosphorus targets within reach.

In the first phase of this project, representatives of local, state, and federal government bodies
were convened to evaluate the regulatory feasibility of developing a treatment facility on Jewett
Brook. The evaluation served to clarify which resource concerns were paramount as well as
potential ways to avoid or minimize impacts to these resources. The resource concerns that
emerged as most challenging were 1) entrainment of fish (specifically larvae) in intake pumps;
2) potential impacts to aquatic organisms due to warming of the stream at the discharge
location; and 3) potential impacts to fish species recruitment due to alteration of the natural flow
regime in Jewett Brook and the Black Creek Wildlife Management Area.

Stone performed a comprehensive review of potential sites in the lower Jewett Brook watershed
for development of a treatment train facility. Two sites on the Dunsmore Farm on Dunsmore
Road emerged as most viable. Each site has advantages and disadvantages. A conceptual
treatment facility design is presented for each site. At this juncture, we believe the Dunsmore 2
site is the best option, because it is more proximate to Jewett Brook and its soil, slope, tree
shading, and access conditions are more favorable. The primary resource concerns could be
addressed in the design and operation of a treatment facility located at the Dunsmore 2 site.
Operating the facility only when flow conditions are suitable will minimize impacts on aquatic
biota.

Assuming seasonal operation (spring and fall), Stone estimates a median total phosphorus
removal rate of 286 kg per year (631 lb./yr) for the proposed Dunsmore 2 Treatment Train.
Using ballpark cost estimates, we predict the cost of P removal at this facility will be about $800
per kilogram.

The Lake Champlain Basin is home to a number of nonnative and invasive species that cause economic and ecological harm to our ecosystem. Federal, state, and provincial partners of the Lake Champlain Basin Program from New York, Vermont, and Quebéc have identified invasive species management as one of the highest priorities in Opportunities for Action, a management plan for Lake Champlain.

This guide highlights a number of high priority non-native invasive plants, animals, and invertebrates that are known to exist within the basin and introduces high-priority invaders that users should be on the lookout for when in the basin. Species inclusion in this guide was based on partner input, reviewed by the LCBP Aquatic Nuisance Species Subcommittee, and the Lake Champlain Basin Aquatic Nuisance Species Management Plan and does not include all known aquatic invasive species in or threatening the basin. This booklet was developed to ensure that Lake Champlain stakeholders—such as boaters and anglers, law enforcement staff, lakeshore property owner groups, park managers and others—have the skills to recognize potentially harmful non-native species in the field. It was compiled by the Lake Champlain Basin Program Aquatic Nuisance Species Subcommittee Spread Prevention Workgroup. Funding for this guide was supported by the National Aquatic Nuisance Species Task Force.

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