A citizens group formed to cut pollution from the Lafarge cement plant said a proposed first-ever state limit on mercury should be cut by more than half.

Comments filed with the state Department of Environmental Conservation by the group Community Advocates for Safe Emissions also called for continuous mercury emissions testing on the plant’s smokestack, which is along Route 9W across from the Ravena-Coeymans-Selkirk middle and high schools.

Under a proposed air pollution permit being considered by the state Department of Environmental Conservation, Lafarge could emit up to 176 pounds of mercury a year.

Mercury is a potent neurotoxin that causes developmental problems in fetuses and children, primarily entering the body through consumption of tainted fish. Mercury tends to enter the food chain through water, where it can be transformed into toxic methyl mercury.

CASE urged DEC to set the plant’s mercury limit at 69 pounds to reflect proposed rules under consideration by the U.S. Environmental Protection Agency.

"We would like to see DEC hold a public hearing on this," said Elyse Kunz, a co-founder of CASE, which formed in 2008 to urge the state to crack down on plant emissions. "There are a lot of questions people want to ask."

Lafarge has announced it expects to modernise the 48-year-old plant by 2016, and convert its wet-kiln process to a less-polluting dry kiln. "Lafarge Ravena hopes that the comments provided to the DEC help to clarify and further improve the final version of the renewed permit," said John Reagan, plant environmental manager.