As California faces another wave of devastating wildfires, including the Hughes, Eaton, and Palisades fires, pool and spa service providers will be on the front lines, helping homeowners recover from the damage left behind.
With as many as 16,000 structures destroyed and 27 lives lost, the toll of these fires extends to properties well outside the burn zones. For many residents, swimming pools have become unintended reservoirs for ash, debris, and firefighting suppressants — posing unique challenges for cleanup and restoration.
The Pool & Hot Tub Alliance (PHTA) offers vital guidance for pool professionals tackling post-fire pool clean-up.
Why Fire-Damaged Pools Are So Hazardous Pools in fire-affected areas often become dumping grounds for ash, but not all ash is created equal. According to the PHTA, the composition of ash depends largely on what was burned and at what temperature.
• Lower-Temperature Fires (<840°F): These fires primarily produce ash rich in organic carbon, which is easier to manage chemically.
• Higher-Temperature Fires: When temperatures rise, the carbon is burned away, leaving inorganic compounds like calcium, magnesium, and sodium.
When wildfires destroy not only forests but also homes and structures—as seen in California’s current crises — the ash becomes even more hazardous.
• Structural Ash Hazards: The intense combustion of homes releases potassium and calcium oxides, which combine with water to form quicklime. This material can harden inside pool filters, creating a cement-like coating that disrupts filtration systems.
But wildfire ash isn’t just messy — it’s toxic. According to the PHTA, the ash found in pools can include dangerous substances such as lead, arsenic, and hexavalent chromium, especially when the fires have burned homes or structures. This makes cleanup more than a cosmetic issue — it’s a matter of health and safety.
The firefighting efforts themselves can further complicate matters. Retardants like di-ammonium phosphate are widely used to suppress flames, but when they settle in pools, they cause phosphate levels to spike.
High phosphate levels in pools were widely reported by pool service technicians after the 2003 Cedar Fire in San Diego, which may have been related to the large amounts of phosphate-based suppressants dropped in the area.
High phosphate levels can lead to water quality issues, algae growth, and even scaling on heat exchangers, a costly problem for pool owners and service professionals alike.
Because it is impossible to determine the nature and amount of foreign materials that have entered the pool, the PHTA’s position is that it is best when allowable, to drain and refill the pool.
Steps for Cleaning a Fire-Affected Pool: Cleanup
From page 6
In cases of homes not damaged but in a vicinity to the fire, PHTA outlines these essential steps:
• Remove all larger debris as soon as is possible.
• Brush all surfaces thoroughly.
• Skim smaller material with a pool net.
• Make sure filter is clean and in operational order.
• Inspect all equipment.
• Super chlorinate the pool to 20 ppm or use a quality chlorine-free oxidizer
• Follow immediately with a clarifier or filter aid material to help remove small ash material to the filter.
• Use of an enzyme can help break down some un-filterable non-living organic material.
• Test and treat for phosphates once the chlorine levels have come down below 5 ppm.
• Add a good broad-spectrum algicide.
• Clean filter as necessary throughout this process.
• Monitor and Protect During Rain: As Southern California prepares for its first winter rains, service providers should take steps to prevent floodwater from overwhelming pools. Use sandbags or other diversion methods to keep runoff out of the pool, particularly in areas prone to erosion or mudslides.
The aftermath of wildfires extends far beyond the initial cleanup. The PHTA warns that hydrophobic soil — created when extreme heat bakes the ground — can repel water and exacerbate flooding during heavy rains. At press time, this has already become a concern in Los Angeles and Ventura counties, where flood watches are in effect ahead of a forecasted rainfall.
The PHTA emphasizes the importance of safety during cleanup. Smoke and ash contain hazardous toxins, so personal protective equipment — including gloves and breathing apparatuses — is essential for anyone working in fire-damaged areas.
Abandoned Pools
For pools adjacent to homes totally destroyed by wildfires, the issue is far more complex. With hundreds — if not thousands — of pools abandoned near burned properties, these stagnant water bodies will quickly become mosquito breeding grounds. Standing water, combined with California’s warmer climate, creates the perfect conditions for outbreaks of mosquitoborne illnesses like West Nile Virus and Zika.
For pool service providers, this presents an opportunity to collaborate with local health departments to mitigate public health risks. Here’s what to consider:
• Coordinate with Authorities: Contact county and city health departments to identify areas with the highest concentration of abandoned pools. Many local governments may be open to contracting with service providers to drain and treat these pools.
• Educate Homeowners: For properties not completely abandoned, inform owners about the importance of proper pool care to prevent mosquito infestations.
• Promote Public Health: Suggest proactive solutions, such as mosquito dunks or other larvicide treatments, to keep stagnant pools under control. (Mosquito dunks contain natural bacterium called Bacillus thuringiensis israelensis (Bti), which is toxic to mosquito larvae but safe for humans, pets, fish, and other wildlife.) The question of responsibility for abandoned pools in fire zones is complex. Homeowners with standing properties may have insurance that covers draining or maintaining a pool, but for those whose homes have been destroyed, the task often falls to local governments.
Public health officials may need to step in, but they often rely on private companies to carry out the work.
This is where pool and spa service professionals can play a critical role.
Consider reaching out to health departments and emergency management agencies. Service providers can position themselves as part of the solution, offering expertise in pool drainage, cleanup, and maintenance.
For more information, visit the Pool & Hot Tub Alliance at www. phta.org.
