WESTERN NORTH CAROLINA - From the steep slopes of the Blue Ridge to the boggy lowlands of Transylvania County, U.S. Army Corps of Engineers crews and contractors continue to tread softly through a landscape reshaped by Hurricane Helene's historic floods.

USACE is currently operating in 16 counties, with as many as four new counties expected to be added soon. Across these jurisdictions, the Corps has deployed contractors who specialize in both environmental compliance and field efficiency. Contractors handling stream debris removal in Transylvania County has earned praise from USACE officials - along with others in neighboring counties - for combining precise fieldwork with environmentally sensitive practices.

Key to their work: heavy forestry equipment outfitted with biodegradable hydraulic fluid - a critical step toward reducing long-term pollution in sensitive environments. This upgrade is vital because even well-maintained forestry equipment - operating at pressures of up to 5,000 PSI - can suffer pinhole leaks or seal failures in hydraulic lines, which power harvesters and forwarder boom arms and grapple claws.

Biodegradable hydraulic fluid - made from vegetable oils and synthetic esters - begins breaking down within days, is 90% degraded into harmless byproducts within 60 days, and is fully assimilated into soil biology with no residual toxicity within six months. By contrast, traditional petroleum-based hydraulic fluid can persist in soil and water for 20 years or more, posing a risk to wildlife, groundwater, and wetland ecosystems.

Site planning with ecology in mind

Before work begins in any sensitive location during the Helene debris cleanup, USACE teams partner with biologists and Quality Assurance specialists to assess local wildlife and habitat conditions. In some areas, drones are deployed to scout ahead in cleanup zones, enabling crews to plan access routes that minimize disruption to streambanks and shoreline vegetation. This approach allows USACE to limit or eliminate streambank clear-cutting, requiring only strategic tree removals to reach difficult debris locations.

With many waterways rerouted or clogged by vegetation and household debris mixed within a slurry of sediment, traditional access points are often gone. In areas where forestry equipment doesn't have direct access to debris in streams, rivers, and lakes, the least disruptive method is to remove the wreckage directly from within the waterway. This is done using specialized equipment designed to preserve the waterway's natural hydrology, while minimizing further erosion and turbidity.

The mix of trees, vegetation, household debris, and small amounts of sediment from individual sites is then congregated at larger Temporary Offload Staging sites, or TOLS. At these sites, debris is laid on timber matting - a layer that creates a stable platform, which also allow excavator claws to pick up material to be placed into various dump trucks, without gouging the soil beneath. Once TOLS sites are cleared, the timber matting is removed and the area is reseeded to promote regrowth of vegetation to the site.

Debris from TOLS sites is congregated once again at regional Temporary Debris Management Sites, where the debris is sorted into various waste streams for recycling or disposal. This method minimizes direct impact to the 3,936 sites identified by county officials across western North Carolina from where the debris was originally removed.

Holding the line on environmental standards

The effort is fully coordinated with FEMA, the North Carolina Department of Environmental Quality, and other state, county, and local jurisdictions. Workers in the field consult with FEMA Environmental Historic Preservation experts to ensure extremely sensitive sites receive special attention to minimize environmental impact.

USACE conducts environmental training every one to two weeks for contractors and subcontractors working on the Helene debris mission. A full-time regulatory specialist from the USACE Wilmington District is embedded in the mission teams. Subcontractors that fail to follow these protocols are stood down for retraining - and can be dismissed entirely.

Source: U.S.Army