Hidden Earth 2023

Evidence of a Past Acid-Metal Mine Pollution Event Found within a Macrotidal Estuary on Anglesey

30 minute Lecture|Lydia De Brett

Abstract

Acid-metal mine wastewater is a source of heavy metal pollution within the United Kingdom. This occurs due to a lack of remediation of closed Acid metal mines preventing mine water seepage. Evidence of a past marine pollution event on Anglesey due to a release of acid mine wastewater from Myndd Parys was recorded in the sediment present in Dulas Bay estuary, a macro tidal estuary 4.4km away. It was found that within the estuary, sediment with a higher percentage of grain size under 63µm had higher heavy metal pollution from copper zinc and lead present within. Evidence of a higher influx of heavy metal pollutants was also found in two cores drilled within the salt marsh of Dulas Bay suggesting more significant metal fluxes in previous times when metal mining was at its peak. Overall, this suggests that greater remediation efforts should be undertaken especially as Myndd Parys is considered for reopening.