An appeal has been lodged against the approval to expand the Medway coal mine, in a move which Boral workers fear could threaten the viability of not only the mine, but  the Berrima cement works as well.

Earlier this year the Planning Assessment Commission gave approval for Boral to double production from Medway, to more than 400,000 tonnes a year.

However the Commission was told there were environmental concerns about heavy metals being discharged into local waterways, although the company claims they are within approved limits.

The appeal has been lodged by the Southern Highlands Coal Action group, and has been submitted with the assistance of the Environmental Defenders Officer.

Alan Lindsay who lives near the boundary of the mine lease says while there have been concerns about the increase in truck movements on Medway Road, his real worry is about the effect mining is having on water quality.

Wingecarribee Councillor and Boral employee Graham Mc Laughlin says any long drawn out and expensive appeal raises serious questions about the future of  the mine and the cement works as well