This is Eileen Wray-McCann for Circle of Blue. And this is What’s Up with Water, your “need-to-know news” of the world’s water, made possible by support from people like you. 
In the United States, Massachusetts regulators have found toxic PFAS compounds in a pesticide the state has used for two decades for mosquito control. According to the Boston Globe, the Department of Environmental Protection tested the Anvil 10+10 pesticide and found eight PFAS compounds. Three of the compounds exceeded state standards. The other compounds found in the mix are unregulated. Because the mosquito pesticide is sprayed from planes and helicopters, there is concern that the chemicals have entered rivers and groundwater. Certain PFAS compounds have been linked to cancers, thyroid problems, and other health issues. The manufacturer of the pesticide says that no PFAS were used in its formula, but that compounds could have been introduced during manufacturing or in packaging. Watchdog groups were skeptical of those claims. In 2019, which was a high-activity year for mosquitoes, Massachusetts sprayed the pesticide on more than two million acres.
Elsewhere in the United States, regulators in New Mexico took a step to protect scarce water supplies in a dry region. The State Land Office said that it will stop selling fresh water from state trust lands for use in oil and gas production. No new authorizations to sell fresh water for fossil fuels will be granted, and existing easements will not be renewed once they expire. Stephanie Garcia, the state lands commissioner, said that the aim is to encourage drillers to use recycled water or produced water for their operations. Produced water is the salty fluid that comes from underground along with the oil. For every one barrel of oil, four to 10 barrels of produced water come with it. New Mexico is the third-largest oil producing state in the country and one of the driest. In the last year, officials there have acted to protect fresh water by finalizing regulations favoring increased use of recycled and produced water in the Permian basin oilfields.
This week Circle of Blue reports on a new study revealing the water contamination risks of plastic pipes exposed to the heat of wildfires.
In California, wildfires have been brutal in recent years. They have incinerated millions of acres of forest and blazed through developed areas with vicious force.
Fifteen of the 20 most destructive fires in California history have occurred since 2015, obliterating thousands of homes and buildings statewide, from the Sierra Nevada foothills to the Coast Range.
Because these fires are now burning where people live — or, people are living where the fires are — new hazards to health and infrastructure have emerged in the ashes. Among them is the contamination of drinking water, which occurred after catastrophic fires in Santa Rosa, in 2017, and in Paradise a year later. Chemical contaminants such as benzene, a carcinogen that affects blood and bone marrow, were also found in community water systems in Santa Cruz County this year following the CZU Lightning Complex Fire.
Andrew Whelton is an associate professor of civil and environmental engineering at Purdue University. He’s  been at the front lines of the search to identify risks to water systems – he’s assessed plumbing damage in Santa Rosa and Paradise.  He and his university research team have found evidence that partially answers a lingering question: what is the source of volatile and semi-volatile organic chemicals that were found in those water systems? Are they pulled into the pipes when water systems lose pressure during fires? Do they come from damage to the plastic pipes themselves?
Laboratory tests conducted by the Purdue team showed that high temperatures affect the plastic pipes used for water distribution and home plumbing. In an experiment, heat caused the pipes to degrade and leach compounds into water. Those compounds include benzene, toluene, ethylbenzene, and xylene.
The study does not rule out the possibility that water contamination occurs when smoke and other chemicals in the air are pulled into the water distribution lines. Whelton believes there are multiple ways in which water can be contaminated in a fire — though for obvious reasons doing field work during a fire to show this is nearly impossible. Nonetheless, the study does show that plastic pipes can contribute chemical contaminants to water after being exposed to heat. Whelton believes that the evidence for the theory shows that this mechanism is quite possible.
Plastic pipes are used for a variety of plumbing purposes, from the large-diameter water mains to the smaller service lines that deliver water into a building. Inside the building, plastic pipes carry hot and cold water, and connect to things like refrigerator ice makers. There are plastics in gaskets, valves, and meters, as well.
The goal of the study was to isolate the effect of heat on plastic pipes. The researchers tested 11 types of three-quarter-inch diameter plastic pipe from eight commercially available brands. This size of pipe typically connects a home to the city water main. The first step was to see whether any chemicals leached out under normal conditions. Whelton said that none of them did. The pipes were then exposed to temperatures ranging from 392 to 752 degrees Fahrenheit, which are still lower than temperatures in some fire situations. The pipes were then submerged in water, and then the water was tested for the presence of volatile organic chemicals.
Even at temperatures that were lower than those in some fire scenarios, the plastics had begun to degrade. Whelton described the polymers in the plastic as a bowl of spaghetti. As heat increases, polymers and atoms begin to break off, like the noodles snapping. When water passes through the pipes, it pulls those bits with it. After testing the water samples in the study, the researchers found that 10 of the 11 pipes leached benzene. Estimated benzene concentrations were as much as a thousand times higher than the California drinking water standard. Levels that were even higher were found in Santa Rosa and Paradise after their fires. The California standard for benzene is 1 microgram per liter, and the federal standard is 5 micrograms per liter.
Whelton told Circle of Blue that this risk is one that many communities will have grapple with. Communities in the western United States face a heightened risk of fire for multiple reasons: climate change, the buildup of potential fuel over recent years of fire suppression, and people moving into vulnerable areas.
In the study, the different pipe materials displayed different patterns of chemical shedding at different temperatures. Vinyl pipes such as PVC were more susceptible to degradation at lower temperatures when compared to pipes made of ethylene. These pipe materials are in widespread use. In the Camp Fire, which burned in Paradise, 35 percent of the water mains in the damaged area were PVC pipe. In Santa Rosa, where a much smaller area burned, 85 percent of the mains were PVC.
Erica Fischer is an assistant professor at Oregon State who studies the impact of hazards on civil infrastructure. She said that plastic pipes have beneficial qualities. They’re durable, easy to install, and don’t readily break under pressure. But, she added, wildfires have introduced new stresses that are only now being analyzed. Fischer told Circle of Blue that the Purdue study showed that these pipes are not performing well in heated conditions similar to a wildfire.
The findings have implications for property owners and government officials. People who live in forested areas are familiar with the concept of defensible space. Usually this means clearing combustible materials from a home’s perimeter in order to protect the building from fire. But this preparation does not include water distribution systems.
State officials have not yet acted on these risks. The Office of the State Fire Marshal told Circle of Blue that there are no provisions in California building standards or defensible space guidelines regarding the type of pipes that should be used in fire-prone areas.
Whelton advocates codes and standards that would determine whether certain infrastructure materials are suitable for regions susceptible to fires. Because ridding plastic pipes of volatile organic chemicals is difficult, water managers should install devices that allow parts of the systems to be isolated. Fischer’s research shows the importance of backflow prevention, to keep contaminants from spreading along a water system. Before the Camp Fire, the town of Paradise did not have backflow prevention. These sorts of infrastructure retrofits are eligible for hazard-reduction grants from the Federal Emergency Management Agency.
Until such changes are made, homeowners need to be aware of the risks with plastic pipes and should protect them from fire the same way they protect their homes. As Whelton put it, “The existing infrastructure that people have needs to be better defended.”
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