Overview
Mining at the Carrshield Lead and Ore Mine is believed to have taken place at various stages from the mid-1700’s to the early 1980s within two mines – Barney Craig Mine and Scraithole Mine. Originally worked for lead, these mines were also later mined for barytes, fluorspar and zinc.
The River West Allen is polluted by metal contaminated groundwater (mine water) draining from these former mine workings. The main source of pollution is the Barney Craig adit, dug by the miners in the 1760s, which is located near to the Carrshield Bunkhouse. The diagram below represents the proposed scheme to treat the polluted mine water impacting the West Allen catchment:
The Environment Agency has been monitoring the mine water and the rivers in the area for many years so they can show how far downstream the pollution extends. This mine water pollutes at least 40km of rivers – in the River West Allen and into the River South Tyne. Zinc concentrations measured in the river downstream of the Barney Craig Mine can be up to 180 times the safe level for river wildlife. To read more about this visit : Rivers polluted by Barney Craig mine water
Groundwater (mine water) containing very high concentrations of metals continues to flow out of the adits all year round and it washes metals out of the ore minerals left deep underground. This will continue for hundreds more years as it is not possible to stop rain getting into the mine workings.
Ore extracted from the Barney Craig and Scraithole Mines was processed at the Carrshields Mine site. The waste material from this processing was stored at one end of the site in a tailings dam or in spoil (waste) heaps around the site. Run off from spoil around the site and metal rich material slumping into the watercourse from the eroding tailings dam further contributed to the problem. We have already completed work to reprofile and stabilise the tailings dam here.
As the mines closed before 2000, the former mine owners and operators do not have to deal with the water pollution they created. This pollution will continue for hundreds more years unless action is taken.