We are almost two months into the monsoon season in the US Southwest, and in that time more than 2,000 liters of rainwater has fallen onto the roof of my small, off-grid house, where it has been captured and diverted into two large tanks. yard. This water is pumped through a filter and into the house to be used for everything from laundry to drinking, but lately I’ve had a lot of headlines screaming at me that my water is full of “perpetual chemicals” and is unsafe to drink.
So do I have to go back to hauling water from the municipal well five miles down the road, 200 gallons at a time, to be safe?
Even though the new interim guidelines from the US Environmental Protection Agency seem to rule that every rain on Earth is unsafe to drink, I’m not tearing up the gutters and pipes I just finished a few months ago. At least not yet.
Associated with all these fears of spoiled rain is(perfluoroalkyl and polyfluoroalkyl substances) that come from chemicals used in firefighting, industrial sources, landfills, wastewater treatment, and even shampoos and packaging. Some studies have shown potential links between PFAS exposure and reduced fertility, developmental problems in children, increased risk of certain cancers, and reduced immune system function.
These manufactured substances break down very slowly, likely making them ubiquitous in our environment, including groundwater that evaporates and floats above our heads where it travels on wind and atmospheric currents before eventually returning to the surface as rainwater. A tiny percentage of this rainwater falls on my roof in New Mexico, passing through a series of gutters, hoses, screens, filters, tanks, pumps and other water pipes before flowing out of a handful of kitchen or bathroom faucets in the house.
You’d think that rain falling on a relatively isolated area of high desert surrounded by public lands would be pretty pristine, but in a world where microplastics are showing up in the Arctic and larger pieces form a miniature floating continent in the Pacific, I’m beginning to wonder if the pristine will go extinct.
Setting up my rain capture system was part of my most epic pandemic project yet, the unfinished off-grid house my family moved into in April 2020. Only in the last few months have I added the final lengths of gutters to the roof of our backyard storage shed to make sure I maximize our rain-catching potential.
And then this month the headlines started screaming at me that I was going to poison my family. And this is not another case of tabloid or clickbait headlines that exaggerate or take things out of context. The sweeping conclusion comes from the mouths of the scientists themselves.
“Based on the latest US guidelines for PFOA [one particular kind of PFAS] in drinking water, rainwater everywhere would be considered unsafe to drink,” Ian T. Cousins, a professor of environmental sciences at Stockholm University, said in a statement.
Cousins is the lead author of a study published Aug. 2 in the journal Environmental Science and Technology that claims the “planetary threshold” for PFAS contamination of our environment has been exceeded.
However, unlike other pressing environmental issues, what has changed in how we view PFAS contamination is not necessarily the level of it in the environment. One of the largest manufacturers of these substances, 3M, stopped making them decades ago, and the amount of PFAS in our environment has actually been relatively stable during that time.
What’s different today are the standards for acceptable amounts of PFAS in the environment that regulators and health officials have decided we should aim for.
“There is increased concern about ingesting/inhaling PFAS because of the very low threshold limit that can cause adverse effects on human health,” Sudarshan Kurwadkar, an environmental engineer and professor at California State University, Fullerton, told me.
That concern led the EPA to introduce new drinking water health advisories for PFAS in June. The directive sets target levels of PFAS concentrations in drinking water so low that they may exceed the capabilities of current testing and monitoring technology.
“From a chemist’s perspective, evaluating the new levels will be challenging,” Jennifer A. Faust, a chemistry professor at the College of Wooster, said by email. “For PFOA (C8), the new recommended level is 4 pg/L (picograms per liter), but the EPA’s own method for analyzing PFOA in drinking water cannot reliably detect anything less than about 500 pg/L.”
But Faust doesn’t dispute the new limits, pointing out that the EPA based them on current toxicology and health research.
“Since the US EPA’s advisory level is lower than most analytical detection limits, it follows that virtually any PFAS detection will exceed the advisory level,” said Stu Khan of the University of New South Wales in Australia.
So the predicament that the new research from Cousins and colleagues tries to outline is this: Our world appears to be filled with matter, largely produced during previous generations, that has been around for a very long time. It would be helpful if more research was done on the potential health effects of these things, but it’s safe to assume that we’d be better off without it at all, at least in our drinking water.
PFAS testing and filtration
This reality also further clouds the question of whether I should drink the precious rain that falls on my desert home.
After all, Faust pointed out to me, “a 2021 study by a team of Johns Hopkins researchers found that PFOA concentrations in bottled water ranged from 170 pg/L to 2,000 pg/L.”
So if bottled water has up to 500 times the EPA’s recommended limit for PFAS, could my rainwater-based home Sodastream refresh actually be that much worse?
“If the remote area you currently live in is not vulnerable to long-range atmospheric transport of airborne PFASs, you should be fine,” Kurwadkar told me.
Of course, I have no idea how vulnerable I am to chemicals forever riding around the world high in the sky before falling on my house in millions of tiny raindrops—I didn’t sign up for any premium subscription that could tell me. that.
However, there are ways to find out. Several companies offer home test kits to check for PFAS in your drinking water. A number of labs will analyze water samples for you for about $200-$300, but I ordered a kit from Cyclopure, which offers an $80 mail-in test.
It will be a few weeks before I get the results for my own water, but I’ll be sure to post an update once they come in.
Faust, meanwhile, reminds me that there are other ways to alleviate post-industrial apocalyptic anxieties than the panic of a toxic falling sky.
“I don’t have a clear answer for you as to whether changing your water sources will reduce your intake of PFAS, but if you’re very concerned, you can look into granular activated carbon filtration systems to remove PFAS.”
Adding a GAC filter to a home plumbing system is a relatively simple task, but it’s still a plumbing job that is rarely actually simple compared to most other tasks in life. Another option is a reverse osmosis filtration system, and tabletop options are available for drinking water filtration that require no plumbing.
Sometimes when technology turns out to be toxic, our only option is to turn to even more technology for rescue. So for now I’m sticking to drinking from heaven while I wait for my results to come in and start comparing filtration options just in case.