Impact of Minewater on Rivers
Numbers of discharges of contaminated minewater to rivers and streams are increasing following cessation of mining many coalfields. Voids in the abandoned mine workings flood and as a consequence of the rise in underground water levels, new discharges are often an inevitable consequence. The discharge may seriously downgrade the receiving watercourse if it contains significant levels of iron, ammonia, aluminum or sulphate that adversely effect the water quality and visual amenity of rivers.
The concentration of iron, often referred to as 'ochre', coats the river bed to the extent that plant life is unable to prosper. The orange coloration of the water is visually unattractive and it limits light penetration necessary to promote life in a healthy river. Consequently, in the absence of plants, neither insects nor fish are able to become well established in the water.
Contaminants in the water often render it unfit for industrial abstractions and even the most basic of uses. Potential water resources for potable and industrial abstraction are lost because of these impacts.
To diminish the effects of discharges of untreated minewater, the Coal Authority and the Environment Agency have established a framework to manage the remediation of the highest impacting sites. Staff from WYG have had a significant involvement in supporting the implementation of this programme. Feasibility studies into the potential for the construction of treatment schemes along with design, construction and commissioning have been completed for numerous sites. These sites are described in following pages of this website.