Opacity Monitoring

Many stationary sources discharge visible emissions into the atmosphere, which often take the shape of a plume. Visible emissions are the visible particulate matter that occurs as the result of a wide range of processes. Such processes may involve smoke exiting a stack at a commercial or industrial facility, smoke exiting a chimney from a fireplace or kiln, or dust produced from driving down a gravel road. Opacity is the degree to which the transmission of light is reduced by such a plume and is typically measured over a 6-minute averaging period.

Visible emissions at commercial and industrial sites are frequently regulated to meet Federal, State or municipal air quality standards. Many permits require a certified visual observer to perform an EPA Method 9 Opacity Test annually. C.T. Male Associates Environmental Services division has an EPA Method 9 Opacity Test certified individual on staff. For more information, contact us at (518) 786-7400 or click here.