6-14 Air

How does the height of the “smokestack” affect emissions disbursement and, specifically, the abutting properties?

RESPONSE 6-14

 

Emissions from a stack mix with the ambient air and become more dilute before reaching the ground.  There are many factors that influence the degree of dilution, including the stack height, velocity and temperature, as well as ambient conditions, such as the temperature, relative humidity, wind direction and wind velocity at the stack exit.  A higher stack will result in a higher plume, which will travel a longer distance to reach the ground at a point further away from the stack, allowing more time for dilution and will result in lower ground level concentrations.

 

Invenergy conducted a turbine stack height optimization as part of the air dispersion modeling analysis completed for the project.  The purpose of this optimization was to determine a range of turbine stack heights at which compliance with all applicable air quality standards could be achieved, while still minimizing CREC’s visual impacts to the surrounding community and its potential impact on air traffic navigation from nearby airports and airfields. 

 

The results of the optimization confirmed that taller turbine stacks would decrease the air impacts to abutting properties but would increase CREC’s visual impact while shorter stacks would increase air impacts to abutting properties but decrease the visual impact further, which is already minimal.  The proposed CREC turbine stack height (200 feet) was the height at which it was determined that air quality impacts and visual impacts to the surrounding community would be best balanced, while still achieving full compliance with all applicable air quality standards.  The turbine stack is approximately the same height as the adjacent cell tower, which is 190 feet.         

             

 

RESPONDENT:

 

Mike Feinblatt, ESS Group, Inc.

 

DATE:

May 11, 2016