Announcements / Progress / Science

New Vermont Water Quality Standards Rule Approved


Individual uses of surface waters may exhibit very high quality for different uses. The new Water Quality Standards provide new tools to protect those uses.

The Watershed Management Division is pleased to report that the new Vermont Water Quality Standards have been approved by the Vermont Legislative Committee on Administrative Rules, and have been filed with the Office of the Secretary of State. This culminates a two-year effort that has modernized the Standards to promote better protection for surface waters and the uses they support. The Standards have been updated in the following manner:

  • The Standards were restructured to account for Act 79. Act 79 was passed in 2016, creating a new classification for surface waters called Class B1. The law also stipulated that specific individual uses may be designated upwardly from Class B2 (the lowest classification) to B1 or even A1. Previously, VT law required that all uses – aquatic life, habitat, swimming, etc., be managed to attain the exact same level of quality, based on class. This was unrealistic, and the new Standards establish a much more practical approach to maintaining the high quality uses of surface waters.
  • The concept of dynamic stream equilibrium is now included in the management objectives for aquatic habitat. The management of streams to support dynamic stream equilibrium represents State policy under Acts 110/138, and the Water Quality Standards now recognize this.
  • The temperature criteria have been improved. The Division has worked with the Department of Fish and Wildlife to examine an extensive dataset on temperature in trout streams. As a result, a new temperature limit has been proposed to complement the existing temperature limits, to protect fishing uses for wild trout fishery waters designated to Class B1. In addition, a “no change from the natural condition” criterion has been established for waters designated as Class A1 for the same fishing uses.
  • Incorporation of biological assessment procedures. The Division has incorporated long-used assessment procedures into the Standards. This lends predictability and transparency to the process of determining if aquatic life use is supported. A new stream type – slow winding streams – has also been added to these procedures.
  • Update to the toxic chemicals limits. Vermont followed a new EPA requirement that toxic chemical allowable limits are to be updated in the Standards whenever new EPA guidance is issued for a toxic chemical.
  • Reclassification of certain surface waters to Class A1. Based on a series of discussions with the Green Mountain National Forest and stakeholders, a series of surface waters have now been designated Class A1 for specifically identified designated uses. This is the first protective reclassification of surface waters conducted in Vermont since 1988.

The new Water Quality Standards, and supporting documentation, may be found online at the Division’s website.

This completed rulemaking effort sets the stage for the Division to begin working on a new Rule that will address how the State implements the antidegradation provisions of the Water Quality Standards, a requirement of the Vermont Clean Water Act.


Surface waters in the southern Green Mountain National Forest that have been reclassified to Class A1. Surface waters in yellow and green colors are newly reclassified, while those that are orange are existing Class A1 streams.