Phosphorus Control Plans

In 2016, EPA established phosphorus TMDLs for the twelve Vermont segments in Lake Champlain. The TMDL places on a cap on the maximum amount of phosphorus that is allowed to enter the Lake and still meet Vermont water quality standards. In response to the TMDLs, the State drafted an Implementation Plan that outlines actions the State plans to take in order to reduce the amount of phosphorus entering the Lake. 

Stormwater from developed lands is a significant source of phosphorus. Under the most recently issued MS4 permit, the Town is required to develop a Phosphorus Control Plan that details how the Town will reduce the amount of phosphorus entering the Lake by approximately 20% from municipally owned and operated developed lands. 

In 2018, the Village received a grant from the Vermont Agency of Transportation in the amount of $50,000 to develop a joint Town and Village Phosphorus Control Plan to strategically implement projects across both communities to reduce phosphorus that are also the most cost effective. The Village hired Stone Environmental in partnership with Milone & MacBroom and the Plan is currently in progress. A final Plan is due to the State by April 1, 2021 and the Town and Village will have 20 years from the issuance of the MS4 permit (2018) to implement the projects identified as having the greatest potential to remove phosphorus.  

In addition, the Town is required to ensure that all “hydrologically connected” road segments and outlets from stormwater systems are brought up to State standards as identified under the MS4 permit. The majority of the road segments are on gravel roads. The State broke down roads into 100 meter (328 feet) long segments. A road segment is considered hydrologically connected if it meets one of the following requirements:

  • It is located within 100 feet of a water resource; 
  • It bisects (crosses) and drains to a water resource; 
  • It is located within the DEC river corridor

An outlet is considered hydrologically connected if it is located within 500 feet of a water source. The Department of Environmental Conservation used their GIS data layer to estimate the number of hydrologically connected road by Vermont municipality which can be seen in the Agency of Natural Resources Atlas. The Town worked with the Chittenden County Regional Planning Commission to create a Road Erosion Inventory (REI) that verifies the road segments, outlets, and best management practices (i.e., stone-lined ditches, increase culvert size, etc.) that need to be implemented to meet compliance requirements. 


Related Documents

Information regarding the Lake Champlain Phosphorus Total Maximum Daily Load and the State of Vermont’s Implementation Plan can be found here:

EPA Lake Champlain Phosphorus TMDL