The catastrophic wildfires and conflagrations in Southern California in January have raised concerns about water quality. To provide information, the California Institute for Water Resources has published a water testing website at https://ciwr.ucanr.edu/Tools/Drinking_Water/.

“Water utilities will publish drinking water notices, so the first step is to investigate communications from your local water utility,” said Erik Porse, CIWR director. “Water testing can always provide more information for homeowners or business owners and it's important to understand how to interpret results.” 

Drinking-water system effects can include:

• Toxins, volatile organics and carcinogens can enter the drinking water system through compromised parts of a water system that get melted by fire
• Ash and runoff can be introduced into water sources, such as from the Hughes Fire near Castaic Lake
• Water treatment systems may be unable to treat incoming water if that water has high levels of solids or contaminants 

The drinking water fact sheet provides an overview of water contaminants with links to water provider websites and a list of verified laboratories where residents can drop off water samples for testing. Typically, residents can visit a lab in advance to get a container and sampling instructions and discuss the best tests to order. 

The fact sheets were developed over the past year, said Porse. 

“It's been a great collaboration with Colleen Naughton's Food-Energy-Water Systems for the Underserved Lab at UC Merced and Celeste Navarrete, our GrizzlyCorps Fellow,” said Porse, “and Erika Cassio Madrazo, CIWR project scientist, provided excellent editing for our translations.” GrizzlyCorps Fellows work on projects that promote regenerative agri-food systems and/or fire and forest resilience.

For more information about the effects of wildfire on water systems, see the 2021 report Wildfire & Water Supply in California, co-authored by former CIWR academic coordinator Faith Kearns.