IT IS often claimed that ''environmentalists'' do not live in the real world. In the case of the Lingerbay quarry (May 25) it is the supporters of the development who are the fantasists.

The first responsibility of anyone interested in jobs in Harris is surely to protect the ones that already exist. Though his article covered most of the main quarry issues, David Ross did not mention the risks associated with ballast water, which threatens the pristine waters around the Western Isles, on which vital sectors of the economy depend. While I am not at liberty to quote the Reporter's findings on this matter, the evidence to the Public Inquiry, including all the risks involved, is fully laid out in the report.

The second responsibility of people interested in jobs is surely to try to provide them now. At the Public Inquiry I and others argued the common-sense view that the aggregate demand figures produced by the Government's forecasters were crazily overstated and were not remotely achievable. In practice that has turned out to be the case, with demand in 1997 running at just 217 million tonnes, compared to a forecast of some 300 million - a shortfall of close to 30%.

Even on the forecast figures, Redland had to work hard to prove any sort of case for the quarry achieving more than a nominal output before the year 2006. On the basis of the actual figures, that target has probably been pushed back another 10 years at least.

The truth of the matter is that, all along, Redland have wanted a blank cheque written on the mountain of Roinebhal, which they can cash when they feel like it anytime over the next 60 years. Except under one scenario, there will probably be no significant employment at Lingerbay for another generation. What there will be is planning blight on every other kind of development.

In the absence of any market demand for Lingerbay, the only scenario in which a quarry there could be viable in the short term is if the Scottish Office caves in to pressure from Westminster to export pollution from the South-east of England (which wants aggregates but not quarries) to the mountains of Scotland.

What Harris needs is not devolution of pollution, but some fresh thinking on the development of remote areas.

Ian Callaghan,

Scarista House,

Isle of Harris.

May 26.