Wildfire damage and contamination to private drinking water wells

Following the 2021 Marshall Fire in Colorado, this study was conducted to better understand private well and plumbing damage and to develop public health guidance. More than 20 post-fire drinking water well guidance documents with varied recommendations were found. Approximately 227 wells were located in the fire footprint. Seventeen properties were visited, and a subset of wells were sampled for organic and inorganic contaminants. Property debris was also collected. Benzene, toluene, and 19 semi-volatile organic compounds (SVOCs) were detected in water extracts of property debris. No wells contained volatile organic compound contamination. Two shallow wells (12 and 15 ft) had debris contamination; one well contained notable SVOC contamination. One multi-home unregulated well system was extensively damaged, lost pressure, and had not been repressurized 11 months after the fire due to financial and technical challenges. Study results highlight the need for follow-up work to understand well system damage and household response.