Two months after a wildfire burned through Paradise, Calif., in 2018, Kevin Phillips, then a manager for town’s irrigation district, walked from one destroyed home to another.
Burned out cars, the occasional chimney and the melted skeletons of washers and dryers were the only recognizable shapes.
“You started to actually be shocked when you saw a standing structure,” he said.
Mr. Phillips, now Paradise’s town manager, was following the team taking samples from intact water meters connected to homes that were now reduced to gray ash. He knew from the Tubbs Fire in 2017 that harmful toxins were likely in the water distribution system: Rapid action would be needed to protect people returning to the community from the dangers of toxins like benzene, which can cause nausea and vomiting in the short-term, or even cancer over time.
Wildfires, which turned skies a dim orange over cities from Seattle to Santa
The water crisis in Flint, Michigan, brought much-needed attention to the problem of potentially toxic metals being released from drinking water distribution pipes when water chemistry changes. Now, researchers reporting in ACS’ Environmental Science & Technology have investigated how hexavalent chromium, known as Cr(VI), can form in drinking water when corroded cast iron pipes interact with residual disinfectant. Their findings could suggest new strategies to control Cr(VI) formation in the water supply.
The metal chromium, known as Cr(0), is found in cast iron alloy, which is the most widely used plumbing material in water distribution systems. As pipes corrode, a buildup of deposits, known as scale, forms on the pipes’ inner walls. Trace chemicals in water can react with scale, forming new compounds that could be released into the water. Some of these compounds contain Cr(VI), which, at high doses, can cause lung cancer, liver damage, reproductive issues and developmental