Read the full article by Tony Davis

“As Tucson-area officials struggle with chemical compounds known as PFAS turning up in drinking water, a scientific debate is building nationally over how much PFAS is too much.

But even as agencies come up with widely different standards on the issue, Tucson Water officials today say they believe the water they served to thousands of customers for an unknown period until late August was safe to drink.

That’s even though its PFAS levels in some areas of the city exceeded those that a federal agency recommends, that the state of Vermont requires and that at least two other states are considering…

The utility’s reasoning is that the only national standard existing today for the recommended maximum level — from the Environmental Protection Agency — is more than twice what Tucson Water was serving its customers.

‘The water is safe for all uses including drinking,’ Tucson Water said in a fact sheet last week. ‘It was also safe during the time period discussed in the Sept. 30, 2018 Arizona Daily Star article.’

Yet the EPA and another federal agency appear to be at odds over this very issue.

The EPA has since 2016 recommended no more than 70 parts per trillion of the two most common PFAS compounds for people who drink it over a lifetime.

Last June, a federal public health agency that’s part of the Centers for Disease Control, the Agency for Toxic Substances Disease Registry, released a previously suppressed draft report that in effect recommended no more than 18 parts per trillion for the same compounds.

Various states are all over the map on this question. Vermont allows 20 parts per trillion, less than one-third of what EPA recommends in drinking water. New Jersey and California are considering 27 parts per trillion.

Minnesota recommends 35 parts per trillion for one common PFAS compound and 27 for another. Michigan has a health advisory level of 70 parts per trillion for determining whether groundwater should be cleaned up. Its government has convened a scientific panel to consider if that should be lowered.

The EPA is also considering whether to impose formal drinking-water limits on the compounds and whether to classify PFAS as hazardous substances. That would increase the agency’s authority to clean them up in its Superfund toxic waste remediation program.

Generally, say researchers, standards for how much PFAS should be in water are growing tighter. The EPA lowered its PFAS health advisory from 600 to 70 parts per trillion only two years ago.

The vast majority of states for now are following the EPA’s recommendation of 70. Arizona legally has no choice but to do that. Our state law forbids officials from imposing environmental standards stricter than those of the feds.

Some researchers are calling for even lower levels, with a 5-year-old Harvard University study urging no more than 1 part per trillion PFAS. The advocacy-based Environmental Working Group says there is no safe PFAS level in drinking water, based in part on a German study.

The U.S. EPA has concluded PFAS compounds are possibly carcinogenic to humans…

Figuring out if that water was safe is ‘quite overwhelming and confusing when so many different agencies have different values,’ responded resident Cindy Dooling, who lives near El Camino del Cerro where the nearest PFAS sampling point came back at 8.6 parts per trillion in August.

Agreeing, Dunbar Spring resident Chris McCreedy asked how the utility can be so certain the water is safe when agencies are saying something different.

‘Obviously if there is a difference, if there are reasons for the differences, I would want to know what the reasons are,’ said McCreedy, a desert ecologist and researcher. ‘I don’t know who was right, what to believe.’ “