How San Diego County is coating its roads with PHOS-CHEK to prevent wildfires
Iain Hoey
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County applies PHOS-CHEK to high-risk corridors
Perimeter Solutions has reported that San Diego County will apply PHOS-CHEK long-term fire retardant to high fire-risk roadways as part of its wildfire prevention strategy.
The company said the County maintains nearly 2,000 miles of roadway, with more than 200 miles designated as high fire-risk, including the Wildcat Canyon corridor.
According to Perimeter Solutions, Wildcat Canyon carries heavy traffic daily, and the steep terrain increases the likelihood of overheating vehicles creating sparks that could start wildfires.
The County explained that the area has historically experienced wildfire activity and also functions as an evacuation route for eastern parts of San Diego County.
County Fire will apply PHOS-CHEK throughout the fire season, including in underserved and vulnerable communities.
Technology and application process
Perimeter Solutions stated that the ground-based PHOS-CHEK uses the same technology as the aerial retardant applied by CAL FIRE aircraft.
It said the ground formulation is uncoloured and designed for application on flammable vegetation and cellulosic materials early in the fire season.
The organisation reported that the treatment provides ongoing protection until heavy rainfall occurs.
It explained that the retardant creates a barrier that slows or prevents ignition when sparks or heat come into contact with dry vegetation.
The company added that this approach gives firefighters more time to contain and extinguish fires.
County leadership perspective
San Diego County Supervisor Joel Anderson said: “My constituents have consistently said that fire safety and prevention is a top priority.
“This innovative and proactive approach we have taken helps keep everyone in our county safer.”
Perimeter Solutions comments
Perimeter Solutions Chief Operating Officer Shannon Horn said: “We are proud to continue our partnership with the County of San Diego in their efforts to protect lives and property from wildfires.
“Their proactive strategy serves as a model for other communities facing similar wildfire risks.
“By leveraging advanced fire retardant technologies like PHOS-CHEK, San Diego County is leading the way in wildfire prevention and demonstrating a commitment to the safety and well-being of its residents.”
Funding support through federal programme
Perimeter Solutions explained that the County’s wildfire mitigation measures are partly funded through the Community Wildfire Defense Grant programme.
It stated that the programme was established through the Bipartisan Infrastructure Law, which provides $1 billion over five years to support high-risk areas.
The company noted that the grant is available to local and tribal leaders working to lower wildfire risks.
It added that communities are encouraged to apply and integrate PHOS-CHEK into their fire prevention strategies.
Relevance for fire and safety professionals
The use of PHOS-CHEK in San Diego County highlights how long-term retardants are being integrated into ground-based wildfire mitigation.
Professionals can observe how application strategies are shifting from aerial-only use to preventative ground treatments in high-risk areas.
The County’s work shows how local governments are combining federal funding with private-sector partnerships to expand mitigation capacity.
These developments provide an example for fire services, emergency planners, and safety authorities in areas facing similar wildfire conditions.
San Diego County applies PHOS-CHEK to wildfire-prone roads: Summary
San Diego County is applying PHOS-CHEK to high fire-risk roads.
Perimeter Solutions reported that the County maintains nearly 2,000 miles of roads.
More than 200 miles are designated as high fire-risk.
Wildcat Canyon is among the areas treated with retardant.
County Fire will use PHOS-CHEK throughout the season.
The retardant is applied to vegetation and combustible material.
It remains effective until a heavy rain event.
PHOS-CHEK is also used by CAL FIRE aircraft during wildfires.
Supervisor Joel Anderson said fire prevention is a community priority.
Perimeter Solutions COO Shannon Horn said the partnership is a model for other regions.
The Community Wildfire Defense Grant partly funds the project.
The grant is supported through the Bipartisan Infrastructure Law.
The programme provides $1 billion over five years.
Tribal and community leaders can apply for funding.
Applicants are encouraged to integrate PHOS-CHEK into mitigation plans.