The EPA and all partners involved in debris removal and management are coordinating efforts to protect land and soil quality. During debris removal, the EPA applied Soiltac, a soil stabilizer, to the ash and debris footprints of burned buildings and vehicles. Application of the stabilizer will prevent ash (and the contaminants within) from spreading to soil and land outside of burned areas.

Ash testing has also been conducted by the DOH to monitor the possible contaminants present within fire impacted areas. Based on data gathered in October 2023, DOH found high levels of arsenic in wildfire ash in Kula, along with elevated levels of lead and cobalt. Samples in Kula were taken from homes built between the 1930s to the 2000s. Similar results were found in Lahaina during testing in December 2023.

The U.S. Army Corps of Engineers (USCAE) is also conducting extensive environmental testing before and after debris removal activities. Soil testing will be conducted to ensure the site is safe and clear of potentially leached toxins. Six inches of soil is being scraped from wildfire damaged sites and then soil quality is tested. If testing shows the presence of any toxins, USCAE performs further remediation until they can ensure the soil is clean and safe for rebuilding and habitation. Cultural monitors are on site during all USCAE clean up and remediation efforts.

Extensive debris removal efforts serve to create clean and safe impact zones. To learn more about debris removal efforts, visit resources from the EPA, USCAE and County of Maui.

DOH: Preliminary ash testing data

FEMA and Maui County:Fire Debris Removal and Environmental Testing Information

U.S. Army Corps of Engineers:Hawaii Wildfire Response Information

U.S. EPA:2023 Maui Wildfires

Disclaimer: The information on this page provides well-informed, broad overviews of environmental protection efforts. Information may not be an exhaustive list of all protection measures taken by local, state, and federal partners. Information contained in this page is subject to updates and changes.

The ash and debris that remain on properties affected by wildfires on Maui pose a threat to human health and the environment. The ash and debris can contain harmful contaminants like asbestos, lead, and arsenic. If disturbed by wind, rain, or reentry activities, humans can be exposed to harmful chemicals. Harmful chemicals can also enter the local ecosystems, endangering wildlife, coral, and potentially entering the food chain.

EPA has reviewed proprietary data on Soiltac®, the soil stabilizer selected for use on Maui, and confirms that it is non-toxic. The agency believes that applying a soil stabilizer is more protective of public health and the environment than leaving ash and debris as-is. Application of a soil stabilizer helps reduce inhalation risks and the spread of ash to water or surrounding properties. EPA applied soil stabilizers to the ash and debris footprints of buildings in Lahaina in coordination with Maui County and local officials. EPA supervised the application of soil stabilizers, ensuring all health and safety guidelines are followed to adequately protect residents and workers.