Assessing water quality risk in water transmission and distribution systems affected by bushfires

Climate change is increasing the risk of more frequent, more intense, and more widespread bushfires. Recent experiences in Australia and the United States indicate that bushfires can place water quality at risk. This can occur from physical destruction of assets such as water treatment plants, the network of pipes and pumps that deliver water to communities, and from destruction of reservoirs and holding tanks. Drinking water contamination can also occur from the leaching of harmful chemicals because of thermal degradation of plastic and other pipe materials during large bushfires. This can be a particular insidious risk since assets often lay underground, with currently limited ability to measure their integrity post-fire. Cumulatively, these risks are of major importance to regional and remote communities, health authorities, first responders, and for the water authorities that build, manage, and maintain water infrastructure.

There are significant knowledge gaps in relation to the risks posed by drinking water contamination from bushfires in the context of a changing climate. This research seeks to address these gaps by providing important baseline research in three priority areas:

• A survey of existing state-of-knowledge in relation to assessing water quality risk in relation to bushfires and cataloguing of recent experiences with analysis of regulatory context, current knowledge, and case studies regarding hazardous chemical leaching on thermal degradation.
• Assessing the risk and vulnerability of water treatment assets and infrastructure across the Barwon Water and Wannon Water service regions in high-risk bushfire prone areas and developing a method to identify high-priority sites and assets.
• Undertaking applied research on how and to what extent bushfires may leach hazardous contaminants into the drinking water supply and identifying mitigation and prevention strategies.