Wildfires can leave surviving homes and their water unsafe—safety tips for residents as they return

When fire evacuation orders are lifted, many assume cleared neighborhoods are safe. However, this is rarely the case. Environmental engineers have observed families returning to homes, turning on taps without knowing if plumbing has been contaminated, and viewing debris removal as the end of recovery. In fact, these stages represent only the midpoint of the recovery process.

Three key safety concerns arise after wildfires: chemicals in surviving buildings, the safety of drinking water, and whether burned lots are ready for rebuilding. Even homes that appear unharmed may still harbor unseen dangers. Smoke, toxic ash, and chemicals from burning structures can infiltrate through windows, vents, HVAC systems, and other openings, settling in ductwork, walls, carpets, furniture, and personal items.

These contaminants can include lead, arsenic, asbestos, and various volatile organic compounds, which pose serious health risks. Without professional inspections, homeowners cannot reliably detect these hazards. Before re-entering a home, owners should consider professional inspections for living spaces, attics, crawlspaces, garages, HVAC systems, ductwork, and indoor surfaces to identify harmful metals, chemicals, and organic compounds.

Testing for lead and asbestos is crucial, as dust can also be tested for these substances. If contamination is found, remediation work must follow, with independent confirmation testing. Drinking water contamination is often overlooked but equally dangerous. A functioning faucet may give a false sense of security, as fires can damage water systems, allowing smoke, contaminated air, or debris to enter pipe networks.

Heat from fires can damage plastic pipes, releasing chemicals into the water supply. Boiling water does not remove these chemicals and may increase exposure. Utilities are responsible for testing and repairing infrastructure up to the property line, but property owners must ensure water safety within the residence, including pipes, water heaters, irrigation systems, and private wells.

Even when utility water is declared safe, contamination may persist inside the building's plumbing. Testing for volatile organic compounds, bacteria, and metals after stagnant water sits for about 72 hours is necessary. Rural and agricultural water systems require similar precautions, with repairs completed by licensed contractors and followed by disinfection and certified testing.

Removing debris after wildfires is just one phase of recovery, and it, too, carries risks. A comprehensive restoration typically involves three steps: first, professional oversight of testing for hazardous contaminants like heavy metals, even after debris removal and topsoil scraping. Next, a notice of complete debris removal indicates only the end of initial cleanup, requiring further review by local health departments or environmental agencies before rebuilding can begin. Finally, thorough remediation ensures the property is safe for rebuilding.