Quantifying the importance of diffuse minewater pollution in a historically heavily coal mined catchment

• Published in: Environmental pollution (1987) 2008, Vol.151 (1), p.165-175
• Main Authors: Mayes, W.M., Gozzard, E., Potter, H.A.B., Jarvis, A.P.
• Format: Article
• Language: English
• Subjects: Applied sciences; coal; Coal Mining; Continental surface waters; Diffuse pollution; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; England; Environmental Monitoring - methods; Environmental Pollution - adverse effects; Environmental Pollution - analysis; Exact sciences and technology; Geologic Sediments - analysis; Groundwater; groundwater contamination; groundwater flow; Groundwaters; Industrial Waste - analysis; Iron; Iron - analysis; Mass balance; Minewater; Natural water pollution; nonpoint source pollution; Pollution; Pollution, environment geology; Rivers; surface mining; surface water; temporal variation; wastewater; water flow; Water Pollutants, Chemical - analysis; water pollution; Water treatment and pollution; watersheds
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2007.02.008

There has been considerable progress in developing treatment systems for point sources of minewater pollution in recent years; however, there remains a knowledge gap in the characterisation and remediation of diffuse minewater sources. Data are presented from the River Gaunless catchment, a historically heavily coal mined catchment in the northeast of England. Instream iron (Fe) loadings were monitored alongside loadings arising from point minewater discharges over a 12-month period to assess the dynamic importance of diffuse sources of minewater pollution. In low flow, diffuse sources account for around 50% of instream loading, a proportion which increases to 98% in high flow conditions. The low flow sources appear to be dominated by direct discharge of contaminated groundwater to surface waters in lower reaches of the catchment. In high flow, resuspended Fe-rich sediments, which are both naturally occurring and derived from historic mining, become the dominant diffuse source of Fe in the water column. Diffuse sources of minewater pollution significantly contribute to instream contaminant loadings under varying flow conditions.