The scheme aims, through joint initiatives between the Government's adviser on nature conservation and British Coal Opencast, to rehabilitate land no longer used for mining. It was said to be 'the first of its kind with a major industry'.
But in a damp valley near Cefn Cribwr, Bridgend, BCO's ambition to tear out 124 acres (50 hectares) of ancient woodland, orchid meadow and the habitat of the rare marsh fritillary butterfly has been dogged by controversy since a public inquiry into the scheme two summers ago.
The inquiry inspector's report is now with John Redwood, the Secretary of State for Wales, whose final decision for or against the development is said to be 'imminent'.
The marsh fritillary is one of the most rapidly declining butterflies in Europe. Its presence near Cefn Cribwr, breeding on its vulnerable food source, devil's bit scabious, qualifies the site as one of regional importance. Massive earth moving, with its juggling of water tables and geological strata, makes it unlikely that the butterfly's habitat would ever return to its original condition.
Central to the problem has been the close relationship between BCO and the Glamorgan Wildlife Trust. Since 1990 they have jointly managed the 250-acre Park Slip nature park, land reclaimed and restored from old BCO workings and adjacent to the proposed site.
The trust has benefited from BCO's financial sponsorship over the years, including the gift, in 1980, of a headquarters building on the park site (refurbished at the company's expense), the salary for a reserves officer and a Land Rover, decked out in BCO's green and white livery.
This relationship between miner and ecologist worries conservationists.
The director of Butterfly Conservation, Andrew Phillips, talks of 'difficulty getting the support of the Glamorgan trust' to defend the proposed site. The trust's decision not to give evidence at the public inquiry in 1991 could be a crucial factor in the fate of the marsh fritillary breeding ground.
As early as 1989 the Glamorgan trust proved a useful ally in BCO's plans to renew opencast mining in the area. In the run-up to the public inquiry its officers provided BCO contractors with helpful evidence.
The trust's work included a survey of bird species on the proposed site, carried out by its reservations officer, Alex Coxhead, whose salary was paid through a BCO grant. BCO's environment consultants paid the trust a fee (said to be pounds 600) for the survey.
Its purpose was to act as a checklist against a similar survey being carried out by Steve Moon, the ecology officer for Mid Glamorgan County Council, which opposed the planning application at the inquiry.
The trust's conservation officer, Nigel Ajax Lewis, also provided BCO with a list of 133 animals, insects and birds to be found in Park Slip - evidence showing a profusion of wildlife restored to a landscape blitzed by mining over 20 years.
Objectors at the inquiry, including Neil Jones, the South Wales organiser of Butterfly Conservation, claimed later that the list had been 'enhanced' with species, including the small red damselfly, that were alien to the park's terrain.
Objectors were also mystified that Mr Ajax Lewis's list was produced at the inquiry without a letterhead to identify its origin. In the margin was a handwritten note which started: 'Peter, as requested . . . ' Mr Ajax Lewis agreed last week that the handwriting was his and that 'Peter' was Peter Weavers, BCO's operations director in South Wales.
More serious was BCO's acquisition from trust headquarters of a highly-sensitive list of marsh fritillary breeding sites, complete with grid references, drawn up by Neil Jones and given to the trust as an act of professional co-operation.
Mr Jones was dismayed to be confronted with it by BCO at the inquiry. 'It's an endangered species and my list was being used by British Coal to say that the marsh fritillary was common in the area,' Mr Jones said. 'It's not the sort of document you'd expect to be given to a developer.'
The Glamorgan trust's reluctance to criticise opencast mining on the boundary of its park - it expects to be given full control of the area by British Coal within three years - was highlighted in November 1989 when the trust's chairman, Gwyn Davis, wrote to Mid Glamorgan planners saying the trust did not wish to object to the work on wildlife grounds.
'As matters stand at present,' Mr Davis wrote, 'there is evidence to suggest that habitat re-creation after restoration will be such as to result in no significant diminution in the total local wildlife resource.
'Indeed experience at Park Slip indicates a very positive attitude towards conservation by the Opencast executive, resulting in the enhancement and possible diversification of such resources in the long term.'
Although conservationists differ about the true ecological value of post-mining restoration work - one dismissed the trust's nature park as 'a good pastiche of countryside created by flower bombing' - the development has been a feather in BCO's public relations cap after it won a conservation prize in last year's Prince of Wales awards.
'The trust seems to think they've done a good job on the site and to some extent they have,' Neil Jones said. 'The problem is they've become so absorbed with it they can't see the wood for the trees, if you'll pardon the cliche.'
Another senior ecologist in the region said: 'The relationships built up by some officers of the trust, with people lunching together, meeting regularly, it becomes friendship. I understand how it happens but it makes me feel the cause of local conservation is being diminished.'
Mr Coxhead left the trust last year to take a biology degree, but he remains a member of its governing council. 'I was there by the grace of British Coal because they paid the trust pounds 10,000 for my salary as reserves officer,' he said.
'I did the bird census because I thought it was important to find out what was on that site. I certainly didn't realise they were going to use it against other conservationists in the form of Steve Moon. It was a most unpleasant predicament to be in.
'While working at the trust I was excluded from all the liaisons between the trust and British Coal, which I felt very cross about. British Coal staff would come in and more or less take over the place. They'd have a meeting with Nigel and I'd be excluded. I was never told anything and I've no idea why.'
Mr Ajax Lewis agreed that the trust had provided information for British Coal. He said Neil Jones's list of marsh fritillary sites had been photocopied in the office by a BCO consultant and taken away.
'I wrote to apologise to Neil for the embarrassment. My concern about the list going out of the building and appearing at the public inquiry was that it was giving incorrect grid references by the order of some magnitude and it had been passed to me to sort out.'
He also accepted that there may have been unintentional enhancement on the wildlife list he produced for British Coal. He blamed a propensity for some species to drift into the park from areas untouched by mining operations - and blips on a faulty computer.
Mr Ajax Lewis thought the trust might do things differently in future. 'I'd like to think we've learnt something from this,' he said. 'Possibly to take a wider view of what information should be gathered for whom, rather than being actually quite keen on rushing around gathering it for all and sundry.'
David Ketteridge, BCO's head office spokesman at Mansfield, was surprised that its donations to the Glamorgan trust should raise questions.
'We give away quite a few second-hand Land Rovers to conservation bodies,' he said.
'Opencast supports 15 wildlife trusts up and down the country. I'm rather surprised if anyone should see that as undermining their morality because quite frequently we'll find trusts opposing us on certain issues at public inquiries.'
He added: 'The whole of the ecology of the British Isles is a landscape which has been affected by man's activities.
'Some people say you shouldn't sup with the devil, even with a long spoon. But other people, such as English Nature, say that business and conservation people should try to work together.'