Evidence for Acid Mine Drainage in an Urban Stream in the West Midlands

A six month study was conducted to outline the overall contamination present in Rough Brook stream, Bloxwich, Walsall. Previous studies in the area outlined that the pH of the stream water was far more acidic than expected therefore acid mine drainage as a cause was investigated. Water and soil samples were collected from Rough Brook and compared to selected control sites in the same area. The samples were collected over three sampling periods in order to determine whether seasonal variation occurred in relation to the leaching of contaminants. The samples underwent elemental analysis via ICP and XRF to specify the concentration of suspected contaminants in the stream. Field testing also outlined the pH, conductivity and dissolved oxygen concentrations in the samples collected directly from Rough Brook. The results of the investigation outlined that conductivity and pH values for the water samples collected were similar to the results obtained for the control sites. In contrast the dissolved oxygen concentrations in Rough Brook were affected by the presence of the sewage works downstream of Rough Brook. The ICP analysis outlined seasonal variation for the concentration of elements in Rough Brook. Seasonal variation was portrayed in the concentration of nickel, manganese, iron and magnesium. Therefore there was evidence that Rough Brook was affected by leachates from the historical iron/brass foundries and coal seams close to the stream. Overall, contamination in Rough Brook was found to be a results of acid mine drainage and the sewage outlet. However, the significance of the contamination was minimal.