The November 2018 Camp Fire in Northern California was the state’s deadliest and most destructive wildfire on record, causing 86 fatalities and destroying more than 14,000 homes. In the aftermath of the blaze, government officials discovered yet another, unexpected casualty: the local water systems. Many of the region’s underground water pipes were contaminated with benzene and other cancer-causing chemicals, and they were sending that water into the buildings left standing.
The origins of the contamination are unclear, but it was likely a combination of fumes being sucked into water pipes when the system pressure dropped, and plastics decomposing in place. This was only the second time in recorded history that widespread drinking water chemical contamination was discovered after a wildfire. (The first was the Tubbs Fire that hit another area of Northern California a year earlier.)
Ten months after the Camp Fire, the region’s major drinking water systems — Paradise Irrigation District and Del Oro Water Company — still contained unsafe levels of cancer-causing chemicals. Benzene levels have been found above 500 parts per billion (ppb) in water from both utilities. California’s safe drinking water limit is 1 ppb. In Paradise, methylene chloride levels were as high as 28 ppb, more than five times the safe limit. Many other harmful chemicals were found — when they were looked for.
Even today, there is still a general state of confusion about the safety of residential drinking water.
The California State Water Resources Control Board added to the confusion during a July 2019 public meeting in Paradise, when its representative, Bruce Macler, made several misleading claims about the drinking water. As engineers who directly contributed to Governor Gavin Newsom’s Camp Fire Water Task Force response, and who have years of disaster response and plumbing experience, we have found this shocking.
At the July meeting, the Water Board official claimed that California’s recommended home plumbing testing procedure would protect public safety. But that procedure advised residents that they only needed to test cold water from the kitchen faucet — a single pipe. What about the other pipes flowing to other faucets? Plus, the state procedure calls only for testing benzene, despite the fact that carcinogenic methylene chloride has also been found in the region’s plumbing, sometimes in pipes that were free of benzene. Strikingly, the California procedure pretends hot water plumbing contamination doesn’t exist, even though hot water is known to carry higher risks of contaminant exposure — a fact that led the Butte County Health Department to warn against taking hot showers. Simply put, the state’s procedure will not determine if plumbing is safe, and it could give survivors a false sense of security.
Macler insisted that benzene isn’t retained for very long in plastic indoor plumbing — that “what goes in, must come out.” But studies from the U.S. Environmental Protection Agency — and our own analysis — suggested that benzene can remain trapped in the walls of plastic pipes for significant periods of time. Using EPA’s own information, we and the EPA estimated that 60 to more than 280 days of continuous water rinsing might be required to flush benzene out of even a moderately contaminated polyethylene water pipe. Water heaters, which contain plastic dip tubes, could be especially susceptible to prolonged contamination.
At the meeting, the Water Board presentation implied that activated carbon filters could be used by residents to protect their homes from volatile organic compounds like benzene and methylene chloride. The filters might work up to a certain point, but in January 2019 the California Water Board warned water filter manufacturer Culligan that carbon filters cannot be used to meet drinking water compliance, because volatile compounds “present an inhalation or contact exposure risk at untreated taps.” In doing so, they invoked EPA’s own Safe Drinking Water Act interpretation.
A month later, the state further muddied the waters by stating “[carbon filters] will effectively remove benzene and other organic contaminants from water.” Aside from a vague reference to the manufacturer’s specifications, not mentioned was that carbon filters have a limited lifetime, one that is cut even shorter when they are subjected to high or repeated doses of a contaminant. Small carbon filters used in refrigerators and on faucets would have a shorter life span than whole house filters. All filters would need monitoring and routine testing — possibly every month, as other states and the EPA have documented elsewhere. But the state did not recommend any frequency. The blind filter recommendation by Governor Newsom’s administration is a recipe for another disaster.
Perhaps most disturbing, California’s Water Board for months told residents that odor was an adequate indicator for the presence of harmful levels of benzene. This, despite years of scientific evidence showing that benzene presents a health risk even when its concentration is too low to be detected by smell. The state even conducted its own human subjects experiment, with persons being given contaminated water from Paradise in an attempt to evaluate odor. State records indicate this prompted acute chemical exposure symptoms such as nausea and throat irritation. California’s own toxicology experts internally pointed out that just 26 ppb of benzene was an acute health risk to children. Despite this, and the fact very high levels were found, the state never compelled water systems to publicly notify their population and require a strict do-not-use water order. The U.S. EPA’s regional office also stayed silent despite learning about the acute health risk to children through the Governor’s Camp Fire Task Force. These actions left the citizens and visitors of Butte County unprotected.
Some survivors have told us that California’s statements are being used as justification to limit insurance reimbursements. Many of California’s decisions — particularly their focus on benzene as the key indicator of contamination — lacked a scientific basis. Just ask the Butte County Health Department, which, when checking business for contamination, smartly did not limit its search to benzene. Ask the Paradise Irrigation District, which found carcinogens other than benzene in its water. Ask the Town of Paradise, which found unsafe levels of methylene chloride even in buildings that contained no benzene.
Macler, in his presentation for the Water Board, implied at the July public meeting that the responsibility for supplying water during an emergency initially falls not to the state but to cities and counties. But Title 42 of the federal Safe Drinking Water Act plainly asserts that under catastrophic conditions, emergency drinking water is the responsibility of the state. Although Paradise Irrigation District and Del Oro Water Company produce safe drinking water, the water arriving at residential homes is not reliably safe. The state is failing its citizens.
In light of the failure of Governor Newsom’s administration to protect its citizens and visitors, we urge insurance companies, homeowners, and health authorities to use a more robust plumbing testing procedure. For many in the state, this is their first time ever thinking about these issues. We recommend that they engage competent water treatment professionals in the testing and treatment of residential water.
Community leaders and politicians, including Governor Newsom, must recognize that their failures and the misinformation spread by the Water Board may likely have already adversely impacted the health of citizens in the area. Other outcomes may not surface for years to come.
While Camp Fire survivors are well on their way to recovery in many respects, they still need assurances that their plumbing is — and will remain — safe. They still need accurate information from reliable agencies. While we have done what we can to support survivors, other agencies with far more resources have stood on the sidelines. These agencies need to be held responsible for their shortcomings — if only so that they’ll do a better job when the next wildfire comes.
Dr. Andrew J. Whelton is a Purdue University engineering professor called in to the Camp Fire response by the Paradise Irrigation District and leads the Center for Plumbing Safety.
Dr. Caitlin Proctor is an environmental engineer and a Lillian Gilbreth Postdoctoral Fellow at Purdue University’s College of Engineering.