A mining boss said most of the 110,000 tonnes of coal he wants to excavate from a site in Carmarthenshire would not be burnt.
Chris James, of Bryn Bach Coal Ltd, has submitted a planning application to the county council to remove the coal from seams under grassland and woodland north-west of Ammanford .
The company has already excavated 70,000 tonnes of coal from the Glan Lash site and carried out some restoration work.
A planning document which accompanies the current application said 50% of the coal produced was used by water filtration companies and as a brick colourant – with neither use involving burning – while the other half was burned for domestic heating.
But Mr James said this ratio had changed.
“The planning department has asked for an in-depth analysis of where the coal is going,” he said.
“We found 75% of it goes to water filtration and brick (sectors) – that leaves 25% for domestic heating.”
The proposed extension site covers 10 hectares, but only eight of them – including a 2.5-hectare woodland – would be mined. The other two hectares would be for storing soil.
If given planning approval, Bryn Bach Coal would employ 11 full-time workers for six-and-a-half years to excavate the coal and process it at the site’s existing washery.
The hours of operation at the extension site would be 7.30am to 5.30pm on Monday to Friday, and 7.30am to 1pm on Saturday.
The processed coal would be taken away by lorries via the B4556, which links Llandybie and Penygroes.
An ecological assessment of the extension site commissioned by Bryn Bach Coal said the proposals did not directly affect any statutory or non-statutory sites designated for biodiversity protection.
The assessment said four protected species occurred within or around the site: marsh fritillary butterfly, dormouse, bat and otter.
The butterfly habitat, it said, would be relocated to fields owned by Bryn Bach Coal north of the extension site.
The assessment said the mining was not anticipated to adversely affect any otters in the area, while no signs of badgers were found during surveys – although they might forage on drier parts of the land.
It added that dormice had been spotted 2.6km from the Glan Lash site in the past, and that the woodland and grassland which Bryn Bach Coal said it would cover the mined area with after removing the coal would be suitable for the animals.
The company said it aimed to provide four times as much woodland than existed before any excavation – and has also commissioned a health impact assessment.
Meanwhile, a liaison committee involving local councillors has been up and running since 2015, with £5,000 given to it each year for good causes by Bryn Bach Coal.
Karen Davies, chairwoman of Llandybie Community Council, which will consider the application at its next planning meeting, said Bryn Bach Coal ran a clean and quiet operation, and that she was not aware of disruption.
“They have been very good members of the community and surrounding area,” she said.