The state Department of Environmental Conservation closed its public comment period January 11 on a renewal application for the LaFarge Ravena cement plant, amid concerns by some environmental groups about potential mercury releases.

LaFarge plans to modernize its Ravena plant.The application will renew the plant's last Title V permit, which expired in 2006. The proposed new five-year permit would cap yearly mercury emissions at 176 pounds, the Hudson-Catskill Newspapers reported.

LaFarge estimated it released 146 pounds of mercury in 2008.  The federal Environmental Protection Agency toxic inventory estimates the plant emitted between 380 and 400 pounds annually from 2003-2006.

Friends of Hudson, which has had lawyers and other experts review the Tiitle V permit document, is concerned that a cap on mercury emissions would disappear if LaFarge decides not to modernize its plant. 

However, John Reagan, LaFarge's Northeast region environmental manager, told the newspaper that pending federal limits on mercury emissions from cement plants will act as a backstop to any loophole, should it exist, in the state permitting process.