(Well, from as far back as 2017.)
After the 2017 Tubbs Fire and 2018 Camp Fire, chemicals were found in buried water distribution networks, some at levels comparable to hazardous waste. Contamination was not in the water treatment plants or drinking water sources. Some homeowners found drinking water contamination in their plumbing.
Tests revealed volatile organic compounds had reached levels that posed immediate health risks in some areas, including benzene levels that exceeded the EPA hazardous waste threshold of 500 parts per billion. Benzene was found at a level 8,000 times the federal drinking water limit and 200 times the level that causes immediate health effects. Those effects can include dizziness, headaches, skin and throat irritation and even unconsciousness, among other risks.
When wildfires swept through the hills near Santa Cruz, California, in 2020, they released toxic chemicals into the water supplies of at least two communities. One sample found benzene, a carcinogen, at 40 times the state’s drinking water standard.
Our testing has now confirmed a source of these chemicals, and it’s clear that wildfires aren’t the only blazes that put drinking water systems at risk. In a new study (https://doi.org/10.1039/D0EW00836B) we heated plastic water pipes commonly used in buildings and water systems to test how they would respond to nearby fires.
The results, released Dec. 14, show how easily wildfires could trigger widespread drinking water contamination. They also show the risks when only part of a building catches fire and the rest remains in use. In some of our tests, heat exposure caused more than 100 chemicals to leach from the damaged plastics.
https://arstechnica.com/science/2020/12 ... wildfires/We tested several popular plastic drinking water pipes, including high-density polyethylene (HDPE), crosslinked polyethylene (PEX), polyvinyl chloride (PVC) and chlorinated polyvinylchloride (CPVC).
Benzene and other chemicals were generated inside the plastic pipes just by heating. After the plastics cooled, these chemicals then leached into the water. It happened at temperatures as low as 392 degrees Fahrenheit. Fires can exceed 1,400 degrees.