The U.S. Army Corps of Engineers is once again looking for unexploded military ordnance in West Hawaii.
At a pair of meetings in Waimea and Kohala in October, the Army Corps announced a years-long plan to investigate nearly 12,000 acres of land for remnants of munitions left behind when the parcels were part of the former Waikoloa Maneuver Area, a 185,000-acre training area that was used for live-fire exercises during World War II.
Earlier this year, the Corps finished a search of a 11,000-acre area in Waimea, finding a single piece of unexploded ordnance: a 2.36-inch rocket warhead.
Currently, the Corps is conducting preliminary scans of three parcels in Kohala extending from Kawaihae Harbor to Waimea, and south along the shoreline around Hapuna Beach and Puako.
Project Manager Richard Tanaka said this phase of the project is a remedial investigation that will determine what sort of objects a deeper study is likely to uncover.
Matt Tucker, engineer with consulting group HydroGeoLogic, said collecting this data will require sending mobile detectors along certain “transects” or paths within the investigation areas. Those transects will themselves need to be trimmed of vegetation, with grass cut to within 3 inches of the ground.
Tucker said these scans will be conducted in such a way to avoid impacting historical and cultural landmarks.
Based on those scans, Tucker said the Corps will identify high-density areas for further subsurface scans, until “intrusive investigations” — actually digging at specific sites where potential ordnance has been detected — begin in 2024.
However, none of this can happen without participation by area property owners.
HydroGeoLogic Hawaii Operations Manager Steven Brown said requests for rights of entry already have been mailed out to property owners and that he hopes that all requests for relevant parcels can be resolved by the end of this month.
Although some attendees at the October meetings raised concerns about impacts to their lawns and gardens, Brown said teams will try to avoid working in manicured areas as much as possible.
“There are some times when we’ll have to go into manicured areas … but we’ll plug those holes, remove a hazard, and then we’ll backfill it and also fertilize that area to make sure you don’t have any dead spots.”
Brown also said that positively identified unexploded ordnance could be detonated onsite if it is determined to be unsafe to move to a different location. In such a situation, he said, the Corps will implement controls to protect surrounding infrastructure from the blast.
“In accordance to our regulations, two people must agree that (unexploded ordnance) is safe to move,” Brown said. “Our goal is to move it someplace safe close by … like a vacant lot and dispose of it there.”
While Tanaka said fieldwork is expected to conclude by the end of 2024, the project itself won’t be over for years: A final report on the project isn’t expected to be published until January 2027.
Email Michael Brestovansky at mbrestovansky@hawaiitribune-herald.com.