Kepco’s plan for a Bylong Valley mine to provide coal security for Korea is the company’s first 100per cent equity investment in Australia, but is also the newest battle line in the clash between coal and agriculture.

Kepco, part-owned by the Korean government, paid Anglo American $403million in 2010 for the exploration licence and coal asset.

An environmental impact statement of more than 3000 pages, placed on public exhibition on Wednesday, said the mine would run for 25 years and provide 90million tonnes of coal over its life, with an average annual workforce of 290.

An economic assessment put net social benefit at between $592million and $757million.

The environmental impact statement (EIS) said 440 hectares of strategic, or prime, agricultural land, and nearly 1300 hectares of equine critical industry cluster land were within the project boundaries, but it argued that  the impact would be minimal.

The project area includes Tarwyn Park, the property developed by Peter Andrews and hailed as the beacon for sustainable Australian land use in the future, which was sold to Kepco in 2014 when Mr Andrews’ son, Stuart, gave up fighting the company because ‘‘they have the law on their side’’.

The EIS argued that the mine offered net economic benefits to the region, state and country, and social and environmental impacts were  minimal or could be managed.

But Lock the Gate slammed the proposal, saying the NSW government needed to fix big  gaps in mining and planning laws before more farmland and water resources were permanently lost to mining.

Prime agricultural land and equine critical industry cluster land were directly affected, said Lock the Gate Hunter spokesman Steve Phillips.

‘‘These lands were supposed to have been made off-limits to coal mining years ago but the government has utterly failed to deliver promises to protect farmland from mining,’’ Mr Phillips said.

The Kepco mine has been described as the new frontier in the clash between coal and agriculture after the shock approval for the Shenhua Watermark mine on the Liverpool Plains.

It has united farmers, environmental groups and academics who oppose the project.

NSW Farmers mining spokesman Tim Duddy said there were some projects that the minerals industry should leave alone because they would do irreparable harm, and Watermark and Kepco were  on that list.

Bylong Valley Protection Alliance’s Craig Shaw, whose property is affected by the project, said  though community outrage had been focused on the Shenhua Watermark decision, the relative impacts of the Kepco mine on Bylong Valley would be even greater than the Watermark mine on the fertile Liverpool Plains.

‘‘If we’re going to make a stand in terms of whether we value agricultural land in this country, then it should be here,’’ Mr Shaw said.