The LA Fires from a Water Treatment Infrastructure Perspective

“We hadn’t had rain in 10 months. It was dry – southern California was a tinderbox. Tuesday evening, the smoke started to come in. When I was packing the car, I looked over the left shoulder, and what is normally the pitch-black silhouette of a mountain was this bright, orange tower of flame that was maybe a mile away.”

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We still don’t know exactly how the recent LA fires started. Various theories point to possible events such as sparking SCE power lines, celebratory New Year’s fireworks or something else. For sure, the fact that we haven’t had more than .1” of rain since May created a tinderbox, and powerful Santa Ana winds turned a fire into a conflagration. Whatever it was, within a few days, the lives of thousands of people were upended. Across the more than 37,000 acres that burned, nearly 16,000 structures have been destroyed, and the eventual cost of uninsured losses is expected to reach around $50 billion. 28 lives have also been lost. As of 1/21, both the Palisades and Eaton Fires are still burning, containment is at 59% and 33%, respectively. And yet, Southern Californian’s are a resilient lot. Recovery planning is already underway. This blog considers the future of these communities from a water treatment perspective. We start by understanding the impact to our water and infrastructure.

Immediate Impact

“We drove back on Wednesday to see what was left. It was like the house and area had collapsed in on itself. I walked around to where our kitchen was and thought: “Oh look, the Le Creuset cookware survived.” It was surreal. I went to my office and games room and thought: “I don’t remember that piece of machinery?” It was twisted metal from our central air system that fell down from the loft. I walked around to our bedroom; there was nothing there.”

Toxic chemicals have entered into local water supplies. When the plastics used in pipes, water meters and household materials burned and melted, they released benzene, toluene, and other volatile organic compounds. PVC pipes and fittings are especially rich sources of these harmful substances. Elsewhere, roofing materials and building insulation released hydrocarbons which would have settled into the local water systems. The chemical agents used to defend property from the fires are also laden with chemical fire retardants, including ammonium phosphate and sulfates. These chemicals contaminate local water in reservoirs, groundwater, local creeks, and rivers. Human diseases that can come about from exposure to benzene can include leukemia and multiple myeloma as well as aplastic anemia. Even in the short-term, smaller levels of exposure can cause drowsiness, dizziness, headaches, tremors, confusion, and unconsciousness. Toluene is not as toxic, but there are still health concerns that come with it, such as headaches, respiratory irritation, and in pregnancy, it can also result in birth defects. Testing, filtering, and clean-up efforts are already underway to head off the worst consequences.

Early Action

A host of local, state, and federal agencies rushed forward to throw a protective arm around our communities. These include LADWP, Pasadena Water and Power, the LA County Department of Health, South Coast AQMD, California State Water Control Board, Cal OES, FEMA, the EPA as well as the various public communications channels. Notices, with warning messages like ‘Boil-Water’ and “Do Not Drink” have been issued, and a variety of health advisories have been communicated through social media, websites, and press releases.

Wastewater Treatment Challenges

It’s already been reported that 10,000 buildings were lost in the worst fires in Los Angeles history. While it’s still being assessed, essential elements of our water infrastructure will likely need replacement and repair.

Damage to the Wastewater Infrastructure

Sewer Lines: Underground sewer lines may have been warped, cracked, and broken. This could lead to contamination of our groundwater. Likewise, fire debris may clog sewer mains; backups and localized flooding may result. Maintenance and Repairs: With the massive chemical and debris burden flowing into our water treatment plants, the system will need additional resources to remove blockages, clean, and filter. Pump Stations will likely experience accelerated wear, and even mechanical failures. It’s likely that these extreme conditions were never envisioned, and that motors, pumps and other parts arts will need replacement sooner than originally planned.

Damage to the Potable Water Infrastructure

The extreme heat of the fires also damaged the potable water network in the same way and released the same sorts of benzene (carcinogen) and toluene toxins into the potable water supply. It’s also highly likely that similar debris (ash, soot etc.) that made its way into the wastewater network has been introduced into the potable water supply. m In addition, the tremendous demand for water resulted in drops in water pressure and hydrants ran dry. In Alta Dena, the Eaton fire also damaged reservoirs and pump stations in Pasadena. Steel and concrete water tanks suffered structural damage, and these are now leaking. Under normal conditions, water only flows outward from pipes (positive pressure), eliminating a backflow of contaminants into potable water. However, the massive demand during fire-fighting operations formed a negative pressure inside the pipes. Contaminated water from outside sources (standing water, damaged pipes, or even fire suppression chemicals, even dirty water from connected fire hoses or industrial pumps) can be sucked back into the drinking water supply. Bacteria (E. coli, Legionella) and other contaminants can enter the distribution network. The fluctuating water pressure or heat damage may also have introduced heavy metals (lead, arsenic, copper) into the water supply. The fires burned residential and industrial areas alike. Anything in the fire’s path became fuel that fed the fire; homes, offices, factories, automotive shops, waste disposal sites, vehicles, electrical components, wires, transformers, batteries were burned in the fire.

Environmental Consequences – Groundwater Challenges

The impact of the fires will have varying impact on the public depending on where people live and work. People closest to the Palisades fire will be better off because they mostly rely on imported water flowing from the Colorado River aqueduct, LA Aqueduct (Owens Valley/ Eastern Sierras), and the State Water Project (the Feather River/ Oroville Dam and Lake Oroville); however, the situation changes for people working or living closer to the Eton/ Alta Dena fire. In this part of town, 40 to 60 percent of the water comes from the Raymond Basin.

It’s possible that some wells may need to be taken offline in the short run to prevent pollutants from the fires from entering the water supply. In these cases, more water will need to be imported from the MWD.

Further out, the ash from burned vegetation and local trash is likely to contain heavy metals (arsenic, mercury, lead) and organic compounds, ash, and debris into the water treatment infrastructure once we do get rain again.

Having addressed the immediate problem, the next step could be prevention of further erosion of groundwater quality. Berms, silt fences and temporary storage basins can all be utilized for this purpose. Likewise, slopes could be stabilized with biodegradable mats or check dams. Examples of these which have been used on other local projects include straw wattles (typically made from straw, flax, rice or coconut), as well as coir mats and logs (100% natural coconut husk), and logs.

Recovery

A full post-fire recovery plan may consist of several phases.

1. Water Quality and System Recovery

Recovery begins with establishing a baseline regarding the extent of local water contamination. This would include rigorous testing of the surface water for substances such as benzene, heavy metals, and volatile organic compounds (VOCs). Over a longer period, groundwater also needs to be continuously tested as ash and sediments leak into the aquifer.

Second, systematic flushing of contaminated pipelines and disinfection of reservoirs and distribution systems will be needed to eliminate toxins and microbial risks brought in by the fires.

Advanced treatment systems, such as activated carbon or reverse osmosis techniques can be very important in this effort.

2. Infrastructure Repair and Replacement

As mentioned above, pipes and tanks are likely to have been warped, cracked and melted in the fire’s extreme heat. Vital to water distribution, these will need to be repaired or replaced. And then there are

those worrisome reports of low-pressure hydrants that appeared during the fire. An independent investigation has been initiated to examine these failures and recommend improvements.

Likewise, the 117-million-gallon Santa Ynez reservoir in Pacific Palisades was emptied in February 2024 for repairs due to a tear in its cover. The absence of this reservoir during the fires contributed to water pressure issues. An investigation into repair delays is underway.

Damaged sewer systems will need to be rebuilt or repaired.

Writing the Check

Both fires are still burning at the time of this writing. No assessments have been made or reported on what the cost to rebuild the damaged water system is likely to be, but with over $50 billion in losses already reported, one can guess it won’t be cheap. Funding will have to come from multiple sources.

Federal Funding: FEMA disaster relief funds, EPA grands or loans, IIJA (Infrastructure Investment and Jobs Act)

State Funding: Cal OES (Office of Emergency Services), Cal Water Boards (grants and low-interest loans through the Drinking Water State Revolving Fund), Wildfire Resilience and Prevention Grants (California Climate Investments), Local (municipal budgets and bonds), Special Assessments

Insurance: Payouts on policies held by water utilities or municipalities

Private Sources: example, Public-Private Partnerships

The historic Palisades and Eton Fires represent the worst fire crisis in our region’s history. However, Caliagua is certain that, as this region has always done, Southern Californians will rise to the occasion to ensure that communities are rebuilt, infrastructure is restored, and life will continue.

“Seeing the community really come together right now – to be there for the people who may need their services, supplies – has been heartwarming. We’ve seen reports of people taking advantage of this horrible situation by looting, but the people rallying together to help each other in the community far outnumber them. To see these little pockets of light is really important.”

After nearly fifty years in business, Caliagua is proud to play a part in the recovery. We stand, ready to serve.

Sources:

Quotes come from The Guardian, 1/10/2025. It Feels Apocalyptic: Californians on the Loss and Devastation from LA Wildfires.

California Fires histogram: https://apnews.com/article/california-los-angeles-wildfires-eaton-palisides-urban-area-a162c86589b9102a85c510246539ab72

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