Ground Applications

201.0 Ground-Based Fire Retardant Operations

201.1 Purpose of Ground Applications

Ground-based fire retardant operations play a critical role in wildfire suppression, particularly in areas where aerial resources are unavailable, ineffective, or require direct support from crews on the ground. Firefighters use retardants to slow fire spread, reinforce containment lines, and create defensive barriers that help protect communities, infrastructure, and natural resources. Ground applications are often employed during initial attack operations as well as extended suppression campaigns.

• Containment Support: Retardants are applied along fire perimeters to slow fire advancement and strengthen containment efforts.

• Structure Protection: Ground crews may apply retardants around homes, facilities, and critical infrastructure threatened by approaching wildfires.

• Operational Flexibility: Ground-based delivery systems can be deployed in locations where aircraft operations are limited by weather, visibility, terrain, or airspace restrictions.

201.2 Ground Retardant Delivery Systems

A variety of equipment and delivery methods are used to apply fire retardants from the ground. The selection of equipment depends on incident objectives, terrain conditions, resource availability, and the type of retardant being utilized. Modern suppression operations often combine multiple delivery systems to maximize coverage and effectiveness.

• Fire Engines: Engines equipped with tanks, pumps, and hose systems provide the most common method of ground retardant application.

• Portable Systems: Backpack sprayers, portable pumps, and mobile tanks allow crews to access remote locations where vehicles cannot operate.

• Specialized Equipment: Certain incidents may utilize dedicated retardant mixing and distribution systems designed for large-scale defensive operations.

201.3 Strategic Uses of Ground-Applied Retardants

Ground-applied retardants are used strategically to support both direct and indirect suppression tactics. By reducing fuel flammability and slowing fire progression, retardants provide firefighters with additional time to establish control lines, conduct burn-out operations, and protect vulnerable assets. Their effectiveness is enhanced when integrated into a broader wildfire management strategy.

• Direct Attack: Retardants may be applied directly along active fire edges to slow spread and support suppression efforts.

• Indirect Attack: Crews can pre-treat vegetation ahead of a fire’s anticipated path to strengthen containment lines and fuel breaks.

• Wildland-Urban Interface Defense: Retardants are frequently used to protect communities and critical infrastructure located near wildfire-prone landscapes.

202.0 Equipment and Deployment Methods

202.1 Fire Engines and Apparatus

Fire engines serve as the primary platform for ground-based fire retardant application in many wildfire suppression operations. Equipped with water tanks, pumps, hose reels, and specialized delivery systems, engines allow crews to transport and apply retardants directly where they are needed. Engine configurations vary depending on terrain, incident complexity, and operational objectives, ranging from large structural protection units to smaller off-road vehicles designed for remote access.

In addition to delivering retardants, engines provide critical logistical support for suppression activities, including water supply, crew transportation, communications, and emergency response capabilities. Their versatility makes them a foundational component of ground firefighting operations throughout North America.

202.2 Portable Equipment and Remote Access Systems

Wildfires frequently occur in areas where traditional firefighting vehicles cannot safely operate. In these environments, crews rely on portable equipment and remote access systems to transport and apply retardants. These tools extend operational reach into steep terrain, dense vegetation, and environmentally sensitive areas where vehicle access may be limited or prohibited.

• Backpack and Handheld Sprayers: Lightweight systems allow firefighters to apply retardants with precision around structures, containment lines, and isolated hotspots.

• Portable Pumps and Hose Systems: Mobile pumping equipment enables crews to move retardants over long distances and into difficult-to-access locations.

• Temporary Storage Units: Portable tanks and collapsible reservoirs provide staging points that support extended suppression operations in remote areas.

202.3 Retardant Mixing, Storage, and Handling Procedures

Proper mixing, storage, and handling procedures are essential to maintaining the effectiveness and safety of fire retardants. Most long-term retardants are supplied as concentrates that must be mixed with water according to manufacturer specifications and agency guidelines. Maintaining the correct mixture ratio ensures optimal coverage, adhesion, and fire suppression performance.

• Quality Control: Retardant mixtures should be prepared and monitored according to approved operational standards to ensure consistent performance during application.

• Storage Considerations: Retardants must be stored in suitable containers and protected from contamination, extreme temperatures, and environmental exposure.

• Safety Procedures: Personnel should follow established handling protocols, including the use of appropriate protective equipment and spill prevention measures when working with retardant concentrates.

203.0 Ground Crew Tactics and Operational Strategies

203.1 Direct Attack Operations

Direct attack operations involve the application of fire retardants and suppression resources directly along the active fire edge. Ground crews use these tactics when fire behavior, terrain, and safety conditions permit close engagement with the fire. The primary objective is to slow or halt fire spread while firefighters establish control lines and extinguish burning fuels.

• Fire Edge Suppression: Retardants may be applied directly to vegetation and fuels immediately adjacent to the fire perimeter.

  • Operational Benefit: Slowing combustion provides crews with additional time to strengthen containment lines and conduct suppression activities.

  • Strategic Use: Direct attack tactics are commonly employed during initial attack operations when fires remain relatively small and manageable.

• Hotspot Protection: Ground crews often use retardants to suppress isolated flare-ups and areas exhibiting increased fire activity.

  • Improved Safety: Treating hotspots reduces the likelihood of spot fires developing beyond established containment lines.

  • Enhanced Control: Concentrated application helps crews maintain control over rapidly changing fire conditions.

203.2 Indirect Attack and Containment Strategies

Indirect attack strategies are employed when direct engagement with the fire is unsafe or impractical. Rather than working directly on the fire edge, crews establish containment lines at a distance and apply retardants to reinforce natural barriers, constructed fuel breaks, and planned control lines. These tactics are frequently used during large or rapidly spreading wildfires.

• Containment Line Reinforcement: Retardants help strengthen existing fire breaks and reduce the likelihood of fire crossing established control lines.

• Pre-Treatment of Fuels: Vegetation located ahead of an advancing fire may be treated to reduce flammability and slow fire progression.

• Support for Burnout Operations: Retardant barriers can assist crews conducting planned firing operations designed to remove fuels between the fire and containment lines.

203.3 Structure Protection and Wildland-Urban Interface Defense

One of the most important applications of ground-based retardants occurs within the wildland-urban interface (WUI), where homes, businesses, and critical infrastructure are located near fire-prone landscapes. Ground crews use retardants strategically to create temporary defensive barriers that help reduce ignition potential and support broader structure protection efforts.

• Residential Protection: Retardants may be applied around homes, outbuildings, and surrounding vegetation to reduce fire intensity near structures.

• Critical Infrastructure Defense: Utilities, transportation corridors, communications facilities, and other essential assets may receive targeted retardant protection during wildfire events.

• Community Protection Zones: Ground crews often work alongside aerial resources to establish layered defensive perimeters around communities facing wildfire threats.