State environmental officials are trying to decide if the Dragon Cement plant in Thomaston is doing things the right way. Dragon is trying to deal with a long-time problem of dust.

Two large dust piles have built up over the years, under previous owners. Critics blame the dust for a variety of health and environmental problems

Last year, Dragon covered the piles with soil and grass. Now its asking the state board of environmental protection to approve its plan to monitor air and water quality, and gradually use up the material in the piles.

But critics say they want proof there aren’t health threats.

"The stuff coming out of their stack blowing off their piles, coming off the backs of the trucks that everybody’s seeing, don’t they have the responsibility to the community to prove this isn’t affecting us in an advcerse way?" asked Tiffany Walker from Neighbors for a Safe Dragon.

"When it comes to health issues, the EPA and Mine Safety and Health have done several studies on cement plants and the industry and they came up with a set of guidelines and those are the guidelines we follow. And they found no evidence they cause human health problems," said Dragon Executive Vice President Terry Veysey.

Public testimony is scheduled for Thursday night, and both Dragon critics and Dragon workers are expected to be there.