How to Protect Your Drinking Water From Lead

After the full impact of the Flint water crisis was revealed, it was almost inevitable that more cities would start to see the same problems when it came to lead in their water supplies. Now it’s been proven that dozens of utilities are underreporting the amounts of lead in their water: 33 cities in the US have been found to have “cheats” built into their lead-testing policies.

The fact that we’d be seeing more water utilities in this situation was a prediction made by Yanna Lambrinidou, a medical ethnographer who served on the EPA’s Lead and Copper Rule task force and one of the researchers on the Virginia Tech team that first revealed what was happening in Flint. “Lead in drinking water is grossly underestimated,” Lambrinidou told Gizmodo this week. “The vast majority of water utilities should not be trusted to protect the public from lead in water.”

In January, I began investigating what we should do to protect ourselves from lead. At the time, I gave some tips for how you might test and filter your water if you had concerns. But as these types of disheartening reports continue to surface, it appears that the best thing to do might be not to worry as much about the testing process—which, as you’ll see, is flawed—and simply take the necessary precautions to remove lead from your water, especially if you have pregnant women, babies, or young children in the house.

The water that leaves your local treatment plant is rigorously tested and may well be perfectly suitable for consumption. It’s the infrastructure that delivers the water to your home which is the issue. Cities that have aging lead pipes have two options for dealing with them: Replace them, or treat the water running through them with anti-corrosives that prevent the pipes from breaking down (in Flint, this anti-corrosive was removed when the city switched water sources). Most cities have used lead lines in their mains at some point, but many don’t know the location or status of those pipes. And even if you don’t have lead pipes, tiny pieces of lead solder or lead rust still might make their way into your water.

A bigger challenge for people who rent is that it’s tough to know for sure if you have lead pipe or solder in the service lines going from the mains to your sink. “Up until 1986 there were pretty lax restrictions, if any,” said Tim Heffernan of The Sweethome, who edited a new report on water filters. Regulations that year set standards for the acceptable amounts of lead in the “wetted surfaces” of a supply system, but it would probably be hard for you to find any kind of documentation for pipe replacement in your building. If you live in a building that’s very new, say 2011, you’re pretty much in the clear. If not, it’s probably not worth finding out. “You couldn’t figure that out even if you tested your water,” said Heffernan. “You’d have to take a scrape of your pipe and run it through a mass spectrometer.”

But even if you’ve determined that your pipes are lead-free, it’s still difficult to know with certainty that your water is completely free of lead. “Because lead in water can release sporadically, you could test now and find 10 parts per billion, and test 10 minutes later and get 1,000 parts per billion, and test tomorrow and get 4,000 parts per billion,” said Lambrinidou.

Marc Edwards, the environmental engineer from Virginia Tech who is heading up Flint’s investigation, calls this the “Russian roulette” phenomenon—you can go to the same tap and collect water 10 times in a row and have no detectable lead at all. Then the 11th time, it’s at levels that are uncomfortably high. That’s not even due to a cheat in the testing—that’s just how lead works, and that’s also how you could be consuming it.

Sweethome recently tested multiple water filters for their lead removal capabilties. The top water filter recommendation after testing for everything from taste to pH is the PUR Classic 11-Cup, which Heffernan has grown to love even more in the months since testing ended. The MAVEA Elemaris XL was Sweethome’s second-choice pick. (Brita filters, which became a fridge staple during the 1990s, are basically bullshit.)

No filter removes lead completely. But NSF International does certify filters for their effectiveness in removing various contaminants, including lead, said Heffernan. “It means the filter lowers contaminant levels to below a specific, very low concentration that meets or improves upon what the EPA considers safe.” PUR is still the winner here with 10 NSF certifications; Mavea has 7. (Brita has 3.) But none of those pitchers received NSF lead certification, so Heffernan’s team came up with their own test, using shavings from a fishing weight to create a lead concentration 16 times higher than the NSF test concentration. From the review:

Despite this heavy concentration, the PUR was able to reduce the lead levels by 97 percent to 0.073 mg/L. That is still seven times higher than the NSF Standard 53 requirement of 0.010 mg/L, but it’s way down from the highly elevated starting point. The MAVEA substantially reduced the lead concentration as well—by 73 percent, down to 0.635 mg/L (60 times higher than NSF certification levels).

“Basically, that’s damn good performance by the PUR under brutal conditions,” said Heffernan. “But neither our test conditions nor the results resemble the NSF’s, and we made sure to be absolutely clear on this.” If you want to check the NSF’s recommendations, the organization has prepared a detailed guide just for lead.

Another thing to note is that all the filters reviewed by Sweethome were gravity filters. This means the water you pour in the top of the pitcher is funneled down through a carbon filtration system of granulated activated charcoal to remove pesticides, then through an ionic exchange filter that grabs the heavy metals. There are also under-the-counter filtration systems that use a single block of charcoal, and, of course, in-fridge filters that can be either type. They were not reviewed by Sweethome, but you can check their effectiveness on the NSF list.

One type of filter you’ll want to steer clear from is anything that promises to reduce “total dissolved solids” or TDS. Some filters claim to remove them all, which is not only bogus, it’s not what you want, since TDS are good for you. “Total dissolved solids are the calcium and sodium that comes out of the literal rocks that your water comes from,” said Heffernan. “If you drank water from the lip of a glacier at the top of the Himalayas, it would have total dissolved solids.”

As for additional tips, letting the water run cold every time you fill up your filter will help flush any additional sediment, including potential lead solder. And a few times a year, especially if you live in a place with a water tank on the roof, take this low-tech maintenance step: “Unscrew your little mesh filter on your faucet, because it is most likely filled with rust,” said Heffernan.

Finally, if you do decide you want to replace your pipes, or simply want to make the investment to improve your home’s value, you’ll need to choose between copper or PVC. Copper is, of course, pricier which is why some people only use copper for “inlet” pipes, and PVC for drains, said Heffernan. “I will say that PVC is louder and it can rattle.”

The bottom line: As cities get their acts together when it comes to more rigorously testing for lead, assume that your faucet might somewhere be connected to lead-bearing pipes and take precautions on an ongoing basis. “I don’t know if testing is even needed since the testing can miss what you are being exposed to, and the testing itself can be misleading,” Lambrinidou said. “Just protect yourself.”

Update: This post has been updated to correct some errors about the testing process. Read the entire water filter review at The Sweethome.