Preserving the past, protecting the planet Published April 29, 2025 By Airman 1st Class Natasha Ninete 36th Wing Public Affairs TINIAN NORTH FIELD, Tinian -- Restoring an overgrown, historically significant airfield on a remote island in the Pacific presented a challenge on the best practice for the sustainable disposal for cleared vegetation. In particular, the sustainable disposal for cleared vegetation was of debate. Common disposal methods, such as burning or dumping in a landfill, produce high greenhouse gas emissions and long-term ecological damage. These factors led to the decision for the 513th Expeditionary Rapid Engineer Deployable Heavy Operations Repair Squadron Engineers Squadron (ERHS) to utilize air curtain incinerators (ACIs). ACIs are portable, energy-efficient and ecofriendly burners that convert wood and vegetative waste into recyclable material. “Right now, our goal with the ACIs is to maximize our throughput and time,” said Master Sgt John Depinto, ACI site lead, 513 ERHS. “We are constantly looking at how to make the process smoother and make it better for the next rotation that comes through.” The current rotation of 513 ERHS Airmen who are forward deployed to Tinian consist of the 201st Rapid Engineer Deployable Heavy Operations Repair Squadron Engineers Squadron (RED HORSE) from the Pennsylvania Air National Guard and the 254th Rapid Engineer Deployable Heavy Operations Repair Squadron Engineers Squadron (RED HORSE) from the Guam Air National Guard. The ACIs are crucial in the clearing process which the Airmen have become trained on how to sift, sort, pile and burn the debris in order to maximize the use of each ACI. The rectangular-shaped burners allow for heat to radiate between four, 4-inch thick and 9-foot-tall walls after a fire is ignited. Once the heat increases, the air curtain is engaged and acts as an invisible lid over the top, trapping and reburning smoke particles until their size is reduced drastically. “It’s a special project with so much history behind it,” said Depinto. “We are reutilizing and rehabilitating rather than building new which makes this project so special.” Every 10 tons of wooded material is turned into one ton of biochar, or nutrient-rich carbon ash, that can be used as an aggregate in farming or construction. The biochar is utilized by the local community to aid in farming and is currently being studied by environmentalists onsite for potential use in the future pavement process for the runways. “This project has a lot of thought-process behind it,” said Depinto. “We have archaeologists and environmentalists onsite and they are guiding us through what the best process is to preserve as much as we can.” This approach not only supports sustainable operations in austere environments but also reinforces the core principles of Agile Combat Employment by enabling flexible, resilient, and forward-deployed capabilities across the Indo-Pacific.