COAL company Lake Coal has applied for permission to build an underground conveyor to link its Chain Valley colliery with the nearby Mannering mine it took control of last year.
Both mines are mainly under Lake Macquarie and the conveyor joining them would run under the ground owned by Delta Electricity between the Vales Point power station and suburban Mannering Park.
Documents on display until June 10 show that Mannering’s owner, Centennial Coal, closed the mine for ‘‘care and maintenance’’ in November 2012.
In October last year, Lake Coal assumed the rights to operate Mannering until 2022, giving it access to the two mines, which both supply Vales Point power station.
Mannering’s coal goes to Vales Point by surface conveyor and Lake Coal says joining the two mines by underground conveyor would allow Chain Valley’s coal to go to the power station by that route rather than by truck.
Maps on display show that the Mannering colliery, especially, had historic workings under some houses on the western side of Mannering Park, and residents say they are still concerned about mine subsidence.
Mannering was formerly known as the Wyee State Mine and began operations in 1960.
Chain Valley Bay resident John Burrows said past history made residents wary but Lake Coal had been open with the residents about its proposals.
“The conveyor does not run under houses and it will take trucks off the road into the power station,’’ Mr Burrows said.
The documents show the underground mine roads to carry the conveyor and personnel would be dug through the Fassifern seam for about 1.6kilometres.
The work would take about 12months, and would result in new mine subsidence of no more than about 20millimetres.
Depending on the seams that had already been mined in that area, the total subsidence, including previous seam collapses, could be as much as 125millimetres.
Lake Coal has approval to extract up to 1.1million tonnes of raw or run-of-mine coal from the Mannering colliery, with another 1.5million tonnes of raw coal available from the Chain Valley mine.
Chain Valley also supplies export coal as well as domestic coal to Vales Point and a Lake Coal spokesman said this would continue.
Construction of the underground road would create work for about 40 mine workers and would increase employment at Mannering from five mine workers to about 20, but some truck driving jobs would be lost.