In California, for example, one can use the federal drinking water standard or the California drinking water standard. Not that using either standard would invalidate the opinion of one who wants to use Mexican water quality standards.
In spite of the lack of any set standard for drawing a clean (pun intended) distinction between "clean water" and "unclean water," PolitiFact California crowned Gov. Gavin Newsom's claim that over 1 million Californians do not have clean water for drinking or bathing with its highest truth designation: "True."
That's supposed to mean that Newsom left nothing significant out, such as what standard he was using to call water "clean."
It's a basic rule of fact checking. If somebody says over 1 million people do not have X, the fact checker needs to have X clearly defined before it's possible to check the numerical claim.
PolitiFact California simply didn't bother, instead leaning on the expert opinions of environmental justice advocate Jonathan London of UC Davis and the equally non-neutral Kelsey Hinton (bold emphasis added):
"Unfortunately, (Newsom’s) number is true,’ added Kelsey Hinton, spokesperson for the Community Water Center, a San Joaquin Valley nonprofit that advocates for clean drinking water.What neutral and objective fact-checker deliberately seeks out only experts who double as advocates for the subject of a fact check?
As evidence, both London and Hinton pointed to a 2017 drinking water compliance report by the State Water Resources Control Board, which regulates water quality. The report shows that an estimated 592,000 Californians lived in a public water district that received a water quality violation in 2017. But that doesn’t include people living in private, unregulated districts.
PolitiFact California's fact check successfully obscures the fact that drinking water standards are arbitrary. They are arbitrary in that those setting the standards are weighing costs and benefits. There is no set point at which contaminants suddenly turn harmful.
See, for example, the World Health Organization's statement about its standard for poisonous chemical arsenic:
The current recommended limit of arsenic in drinking-water is 10 μg/L, although this guideline value is designated as provisional because of practical difficulties in removing arsenic from drinking-water. Every effort should therefore be made to keep concentrations as low as reasonably possible and below the guideline value when resources are available.The case is the same with other contaminants, including those yet to be named by regulators. There is no objective line of demarcation between "clean water" and "unclean water." At best there's a widely-accepted standard. PolitiFact California only mentions state standards in its fact check (the word "federal" does not appear) while citing reports that refer to both state and federal standards.
There's a clear solution to this problem. Politicians, if you're tempted to talk about how many do not have access to water meeting a given standard, cite the standard by name. Fact-checkers, if you fact-check claims about water quality that avoid mentioning specific regulatory standards and instead use the slippery term "clean water," realize that you're fact-checking an opinion.
PolitiFact California let slip a wonderful opportunity to educate its readers about water quality standards and what they mean in real life.
PolitiFact California describes environmental justice advocate London as "a UC Davis professor who’s written about contaminated drinking water."
Did PolitiFact California not know London advocates for "environmental justice" or did it deliberately hide that fact from its readers?