As the known drinking water nerd amongst my friend group, I have been informally fielding questions about whether their water is safe to use near the wildfires in Southern California. Some common questions I’ve heard include: How do I know if I can drink the tap water? Can I shower with it? When will it be safe? Beyond more generally getting the facts right on the water and wildfire issues in California, as this Guardian headline suggests, it’s smart to assume the worst about the safety of drinking water in and throughout the immediate aftermath of devastating disasters like the Los Angeles fires.
Why be concerned about the safety of your drinking water after a major fire?
As colleagues so comprehensively explained in their “Wildfire and Water Supply in California” report, there are a lot of pathways by which a wildfire can make your tap water unsafe (and a lot of great ideas on how to adapt to this growing challenge). In Northern California, the Tubbs Fire’s effects on Santa Rosa in 2017 and the Camp Fire, which burned the entire town of Paradise only a year later, were among the first wildfires known to cause widespread drinking water contamination in cities.
Wildfires in forests and wildfires in urban areas have different consequences. Alarmingly, after the Tubbs and Camp Fires, researchers found evidence of post-fire contamination from volatile organic compounds (VOCs) like benzene, which is carcinogenic, and also from heavy metals, microbes and other contaminants that pose both immediate and long term public health risks. As fossil-fueled fires get worse, tap water contamination concern grows. Drinking water may not be safe for months, depending on the severity of the damage.
To name a few ways water can be contaminated post-fire:
- Incineration of urban infrastructure—houses, buildings, electric wires, etc.—leaches toxic chemicals not only into our air but when hot enough, can melt the underground pipe network that deliver drinking water.
- Toxic runoff from the combination of burnt infrastructure, any fire retardant that has been dropped and water to fight the fires, infiltrates into the ground and any stormwater system.
- Any disconnection or disruption to an otherwise closed loop treated drinking water distribution system creates risks of contamination.
- Distribution network depressurization may also allow for contaminant transport between differently impacted parts of the distribution system.
I live in or near a fire-impacted community, what should I do?
Figure out who your water provider is if you don’t know. Community water systems provide drinking water for most Californians, and there are a few tools to consult to identify your water system:
- The Community Water Center’s Drinking Water Tool, features an address-based search tool available in Spanish or English.
- For residents of LA County, the UCLA LA County Water System Governance Map, shows the service areas for more than 200 systems in the county, and is available in Spanish or English.
- The state regulatory agency for drinking water maintains a Human Right to Water Portal, which is also address based and includes not only community systems, but also the schools and daycares responsible for complying with safe drinking water standards.
Then, check your water provider’s website for any advisories like “do not use”, “boil water”, or “‘do not drink”’ notices. (Learn more from the CDC about the difference between them). Depending on the contamination issue, and unless advised by your water provider, it’s unlikely that you can self-treat the water to make it safe by boiling, filtering, adding chlorine or other disinfectants etc.
Check out the LAist Cheat Sheet which compiled thorough FAQ for LA area residents, including how to understand different advisory types, where to get replacement bottled water and your local water provider’s phone number to get your questions answers.
Areas affected by Do-Not-Drink-Water notifications and other water advisories are dynamic. Large water providers like Pasadena Water and Power and LA Department of Water and Power are actively testing and working to get water back to regulatory standards. Smaller systems may have a harder time recovering.
The above concerns and suggested steps are focused on the safety of the tap water being delivered to your house and do not address very real concerns due to on-site contamination from damaged infrastructure on private property. Always review official resources for those impacted by the LA Fires: https://www.ca.gov/LAfires/.
I have a domestic well, what should I do?
If you are not in the service area of a community water system, your house may have a private domestic well. All the fire-related toxic substances infiltrate the soil and reach our groundwater, they contaminate it with dangerous substances that any added chlorine or household point-of-use filters may not remove. That translates to a higher level of pollutants in our tap water, especially when fires occur near a drinking water well.
Domestic well owners are responsible for managing their own water quality, even when impacted by events outside their control. While a brand new law now requires landlords to ensure their rental properties’ wells are tested, there is no state agency that regulates domestic well water quality they way they do for water systems.
Some ideas on how to learn about the safety of your tap water:
- Assess your well if impacted by wildfire, considering using the CDC’s rapid assessment form
- Review the SWRCB’s Guide for Well Owners and Well Testing Program Directory, and search by your county to see if which programs are available in your area.
- Follow the CDC’s checklist depending on issues experienced from loss of power, to loss of pressure and hire licensed professionals to repair or replace damaged components.
- If your house also has a septic tank, check for any signs of damage that could cause issues for indoor plumbing or domestic well contamination.
- Review official state resources for those impacted by the LA Fires: https://www.ca.gov/LAfires/
Not impacted by the fires, but want to help? Fire recovery will be a long process, and donations of critical supplies like bottled water will be needed long after the media moves on from this disaster. Find a trusted local organization, like the Pasadena Jobs Center, an organization coordinating volunteers on the ground and recommended by a friend who grow up in Altadena and lost their family home in the Eaton fire. Consider directly supporting mutual aid groups now and in the coming months.