Post-fire contaminated drinking water system guidance released

EPA lessons from wildfires, VOCs, and source water protection

The U.S. Environmental Protection Agency (EPA), Office of Ground Water and Drinking Water and staff from EPA Regions 8, 9, and 10 have created a recommended practices factsheet: Addressing Contamination of Drinking Water Distribution Systems from VOCs After Wildfires.

The best-practices factsheet compiles lessons learned from drinking water utilities that have been impacted by wildfires. In particular, the utilities have observed elevated levels of several Volatile Organic Compounds (VOCs) such as benzene in water mains, service connections, and building fixtures. The presence of these chemicals complicates and slows recovery efforts.

The guidance describes the occurrence of VOC contamination, contamination sampling strategies, and mitigation techniques in addition to potential mutual aid and funding options for public water systems. The information may also benefit private water systems and well owners.

USGS 2021 sediment sampling after 2020 CZU wildfire | photo credit Amy East, USGS Pacific Coastal and Marine Science Center | Public domain

The EPA, Water Security Division webpage “Building Wildfire Resilience for Water and Wastewater Utilities” also provides a concise Wildfire Incident Action Checklist for preparation and response as well as a paper developed by EPA and Water Research Foundation, Effects of Wildfire on Drinking Water Utilities and Best Practices for Wildfire Risk Reduction and Mitigation.

EPA Regions 8, 9, and 10 comprise the western U.S. where drought conditions, record-breaking temperatures, and declining absolute humidity pose greater fire risk and environmental impact. In recent years, these states have experienced significant forest fires that have destroyed land and severely affected water quality by means of soil erosion, increased flooding and debris flow. EPA research also notes that wildfires can “result in the resuspension of legacy mine and industrial waste that had settled in river bottoms.”

Discover more research highlights at the EPA webpage “Wildland Fire Research: Water Supply and Ecosystem Protection.”

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