What is the Nent Haggs Mine Water Treatment Scheme?

The Nent Haggs mine water treatment scheme was built to remove metals from one of the most significant sources of pollution in the River Nent. Each year, up to 3 tonnes of the harmful metals, cadmium and zinc, are released into the river from the Haggs adit, an abandoned mine water drainage tunnel. In 2019, planning permission was granted for the Coal Authority and Environment Agency to build a mine water treatment scheme and improve water quality for people and wildlife in 60km of rivers.  

Mine water released through the adit is captured, flows by gravity to the Horse and Wagon field from where it is pumped through a 2.5km pipeline to the treatment pond site. The mine water is split between three treatment ponds which contain a layer of natural materials including limestone gravel, straw and wood bark. Natural processes capture most of the harmful metals in this layer. The treated mine water then goes through an odour control system to prevent any smells, and aerobic reedbeds, before being released back into the River Nent.  

The map below shows the location of the scheme.

Site 4 compound shows the boundary of the mine water treatment scheme whilst Site 38 shows the Horse and Wagon field