Above: State-contracted SEAT T-831 drops brilliant blue FireIce HVO-F®. Courtesy photo.
Efforts are underway in Colorado to better evaluate how water enhancers delivered from a single engine air tanker can be more effective than retardants in fighting wildfires.
Colorado historically has only loaded long-term retardant into SEATs. These chemical concentrates are mixed with water and alter fuels so they do not support combustion. Retardant is dropped adjacent to — or ahead of — the fire to create a chemically induced fire break at its perimeter.
Molecular bonds from water enhancers, however, slow evaporation by creating a thermal protective coating. SEAT drops of water enhancers are mainly used in direct attack to slow or halt the fire’s rate of spread long enough for ground resources to access the fireline and mop up or supplement the knockdown process.
These gels have generally been limited in use in recent years, and field testing has been minimal. Information about water enhancers’ availability, use and effectiveness is sparse at best.
The study, lasting throughout the 2017 wildfire season in Colorado, has the following objectives, according to the Colorado Division of Fire Prevention and Control:
- Observe and evaluate drops of water enhancers on wildfires and record information about 1) whether the water enhancer stopped or slowed the forward advance of the fire; 2)whether the water enhancer reduced fire intensity to a sufficient level for ground crews to manage the fire; and 3) whether the water enhancer persists on the surface fuels long enough to prevent hotspots from redeveloping or the fire from burning through the drop.
- Determine whether water enhancers delivered from a SEAT are effective on wildfires in Colorado. Effectiveness will be viewed in terms of how effective the products were in achieving the desired suppression objectives.
- Collect as much data as possible regarding the effectiveness of water enhancers used during initial attack and on emerging fires.
- Share lessons learned from the evaluations with interested parties, including cooperators and researchers.
- Test and evaluate newly developed ground-based mixing/batching equipment to assess the efficiency of the mixing and loading processes and the ability of the equipment to reduce response times.
“SEATs loaded with water enhancers will respond to fires on State and private land, as well as to fires under the jurisdiction of BLM, the National Park Service, and USFS. Mixing will be at the recommended ratios in the USFS Qualified Products List for each product on all drops. For the first load on each fire, State and Federally contracted SEATs will respond to the incident with water enhancer unless the ordering unit clearly specifies the need for LTR instead.
Decisions regarding where, when and how to apply a particular aerial retardant or suppressant are typically under the discretion of the Incident Commander, so if at any time the Incident Commander or the Air Tactical Group Supervisor feels that the enhancers are not performing as desired, the Incident Commander can immediately order that the SEATs be loaded with retardant.
The three water enhancers being evaluated in the study are: FireIce HVO-F, BlazeTamer 380, and Thermo-Gel 200L — each is approved by the U.S. Forest Service for use in SEATs.
The Center of Excellence for Advanced Technology Aerial Firefighting, with support from the Division of Fire Prevention and Control’s Aviation Unit and the Bureau of Land Management, is conducting the study.
After weighing input from researchers and firefighters, investigators will compile a preliminary and final report about the project’s findings.