|Air Pollution Control Division tells applicants that no decisions have been made about pre-construction monitoring.|
State of Vermont
March 3, 1999
RE: Southern Vermont Gas ^ Proposed Power Plants
Dear Mr. Folle:
In response to our telephone conversation yesterday, I am enclosing an update of Vermont,s Air quality Impact Evaluation Guidelines (1/6/99). This revised document should contain the information on receptors and elevation assignments your staff had questions on (see page 10). I should also mention that in addition to visibility impacts in Class I areas, a deposition model (e.g. nitrogen deposition) would likely be required by the Federal Land Manager (U.S. Forest Service). The current recommended deposition model is CALPUFF. I have attached the cover page of a U.S. EPA document describing the procedures (SEPA-454/R-98-019). Please be aware that impacts on the Great Gulf Wilderness Area in New Hampshire may also need to be assessed. The regional contact at the U.S. Forest Service is Nancy Burt, 802-747-6742, Green Mountain National Forest, 231 North Main Street, Rutland, VT 05701
I also contacted U.S. EPA Region I to discuss Ozone Transport Region (OTR) requirements under the 1990 Clean Air Amendments. Because Vermont is treated as moderate non-attainment for ozone as a result of the OTR, major sources for the pollutants NOx and VOCs are subject to non-attainment provisions, including LAER and offsets. As you know, LAER is the lowest emission rate which has been achieved in practice for a given pollutant. Region I has informed me LAER is at the moment considered to be 2 ppm NOx for gas turbines. Any major NOx application should begin at this level and also include a discussion of other transfer technology which is technically feasible. It is uncertain what level of VOCs or CO are expected from the proposed plants and therefore will have to be addressed accordingly in the application as well.
Finally, we have not made any decision on the need for meteorological pre-construction monitoring. It would be helpful to have a modeling protocol submitted which would provide more detail about these projects. This information would enable Vermont to provide you with a timely response.
Please contact me if you have any questions.
Copyright © 1999 by Vermonters for a Clean Environment
Updated: October 4, 1999