THOUSANDS of hectares of heather moorland could be damaged if a new processing plant is built at the Wensley Quarry, near Redmire, English Nature and two parish councils have warned.

Describing how Yarker Bank near Leyburn was often covered in dust from a similar roadstone coating plant, Coun Andrew Jordan said at Redmire Parish Council on Wednesday evening: "It would be a tragedy if the SSSI gets in that condition."

The new plant at the quarry, owned by Tarmac, is within 400m of Lovely Seat, the Stainton Moor site of special scientific interest (SSSI). It is within the North Pennine Moors special protection area and is therefore recognised as a significant European site and covered by the 1994 conservation regulations

Colin Newlands, English Nature's conservation officer based at Leyburn, has asked Richmondshire District Council's environmental unit to make an appropriate assessment under those regulations as to how emissions from the plant would affect the heather moor.

And both Redmire and Preston-under-Scar parish councils are also asking the county council to consider any adverse impact on the environment. "I'll be keeping an eye on the matter," said County Coun Roger Harrison-Topham.

Mr Newlands pointed out that emissions from this plant would be alkaline and was concerned that the dust could both smother plants and alter the acidic nature of the soil. He said the moorlands were of international importance for their blanket bog and heather which sustained golden plovers, short-eared owls, red grouse, curlews, snipe and redshank plus merlins, peregrines and hen harriers.

Dr Sam Ellis, the regional development officer for the North of England for butterfly conservation, is also asking for a proper environmental assessment to be made.

He said that within 500m of the quarry there were four sites sustaining the Northern Brown Argus butterfly, one of the rarest butterflies in the north of England and dust covering the vegetation might affect them.

Besides the impact upon the moorland, it was pointed out at Redmire Parish Council that the plant could also affect the water table. This would have a direct impact upon Redmire as the village gets its water supply from a local spring.

Preston-under-Scar Parish Council is also concerned about the increase in lorries using the quarry. The councillors understood that Tarmac wanted to produce 100 tons an hour at the plant. This could mean an additional eight 20-ton lorries leaving the site each hour, plus those bringing in some of the raw materials.

There were questions about whether the chimney at the new plant would be visible and the affect of the vapour and dust on the villages and countryside in an area heavily dependent upon the tourist trade.