A man who has been taking aerial photographs of Marcellus Shale gas wells and the area surrounding them will present his photographs and what he has learned about gas processing at 12:30 p.m. Saturday at the Butler Public Library, 218 N. McKean St.

The free talk is sponsored by Marcellus Outreach Butler.

For five years, Bob Donnan, a state resident who opposes the fracking process of gas drilling, has used photography to document landscape changes in the tri-state area.

Infrared camera video footage recorded by Earthworks and shale test of local emissions from a gas well under construction and gas industry related infrastructure such as a processing plant and a compressor station also will be presented.

Lisa Graves-Marcucci from the Environmental Integrity Project will talk about the air quality and the permitting of these facilities.

Also, representatives of citizen groups concerned about the gas industry in their communities will discuss their activities.