Johnston, D.M.; Stewart, C.; Leonard, G.S.; Hoverd, J.L.; Thordarsson, T.; Cronin, S. 2004 Impacts of volcanic ash on water supplies in Auckland. Part I . Lower Hutt: Institute of Geological & Nuclear Sciences. Institute of Geological & Nuclear Sciences science report 2004/25 83 p.
Abstract: Auckland lies on the active Auckland Volcanic Field and during some climatic conditions is downwind of the active Taupo Volcanic Zone. Over the past few years a number of reports have evaluated volcanic risk to Auckland’s infrastructure. Building on this previous work, and summarising a range of international case studies, we (a) evaluate the potential for physical and/or chemical contamination of water supplies from volcanic ashfall and (b) outline factors to consider in mitigation before, during and after an ashfall event. The relevant properties of volcanic ash are summarised, especially its abrasive, corrosive, leachate-forming and suspendable nature. (auth)