LAHAINA, Maui, Hawaiʻi — The first soil samples were collected at a property site cleared of debris by the U.S. Army Corps of Engineers in Kula, marking a milestone with the Hawaiʻi Wildfires Debris Mission, Nov. 18, 2023.
If the samples come back below the Hawaiʻi Department of Health cleanup goals, the property owner can proceed with their rebuilding effort.
This comes a little more than three months after devastating wildfires fueled by high winds and dry conditions swept across Kula and Lahaina, Maui, Aug. 8, 2023. The sampling will continue across Kula as more impacted sites are cleared.
“At each location, six inches of soil is scraped off of the top and then the contractor lays out decision units and collects the samples,” said Environmental Protection Specialist Jean Barnes, who is from the Fort Worth District. “The samples will be analyzed for elevated levels of metals such as arsenic, canec, lead, and cadmium. If they come back showing elevated levels of contaminates, the area will be scraped and sampled again.”
If the samples show results below the cleanup goals, the property undergoes erosion control and hydroseeding, and handover to the property owner is completed.
Currently, the soil samples are packaged and sent to the continental U.S. where they are lab tested, a process that takes several days before results are available. Eventually the soil sampling will begin in Lahaina, and the USACE-managed contractor ECC is using an XFR field instrument for onsite testing of the soil samples.
The contractor said the instrument reads the metal content for a whole list of metals. It is set to take a reading every 45 seconds and it is done ten times on each sample packet to get an average. At the end of the day, the data is downloaded into a program and later it is compared to the lab results.
If the correlation between the two is good enough, then in Lahaina it may be possible to do a certain number of samplings in the field without sending them all to the lab. It would result in instantaneous data and eliminate the delay in waiting for lab results.
FEMA tasked the U.S. Army Corps of Engineers to execute the debris removal mission on Maui and USACE is managing contractor ECC to fulfill the mission.