Scientist Discusses Drinking Water Contamination

Earlier this week, tap water testing conducted in 18 states by the Environmental Working Group (EWG) found New Martinsville had the second-highest level of PFAS in the country at 40 parts per trillion.

PFAS, more commonly known as “forever chemicals,” are manmade chemicals used in an array of industrial processes and consumer products, but linger in the environment and pose a risk to human health.

Reporter Chris Schulz spoke with EWG Senior Scientist Tasha Stoiber about water contamination, its health risks, and possible solutions.

This interview has been lightly edited for clarity.

Schulz: Tell me what the Environmental Working Group is and what they do.

Stoiber: We are a nonprofit research and advocacy organization. We are largely based in D.C. and have offices in California and Minnesota. Our mission is to empower people to make healthier choices in their life. We do research and outreach and education to help reduce chemical exposures in your daily life.

Schulz: What do you focus your research on? 

Stoiber: I work on a number of different areas, looking at drinking water contaminants in the U.S., PFAS of course, other contaminants like hexavalent chromium. Outside of drinking water and drinking water filters, I also work on chemicals in consumer products. PFAS is pervasive in that space as well. Also some work in other consumer product areas like mattresses, and also food additives. So a wide portfolio, but I definitely spend a lot of time thinking about chemicals in drinking water, and the drinking water filters that take those chemicals out.

Schulz: Can you give me an idea of what some of the contaminants historically have been that people are concerned about in their water and what the concerns are today?

Stoiber: There are a number of drinking water contaminants, some of them are regulated, some of them are unregulated. Our focus is always working towards getting regulations on the books. There hasn’t been a new drinking water regulation for an unregulated contaminant in the last 20 years. The EPA’s proposal for a new MCL (maximum contaminant limit) for PFOA or PFOS, that is something that has been a long time coming and that we’ve been waiting for, for quite some time. 

The process for setting drinking water regulations in the U.S. is quite lengthy, it’s quite inefficient. There’s a huge burden of gathering information before that can happen. That’s why there hasn’t been a new regulation. And that’s why these new regulations for PFAS are going to be quite significant. 

Drinking water contaminants that people think about, and maybe people might be a little bit more aware of: there’s been a lot of attention placed on lead in the last few years, given some of the contamination issues that have happened in some cities. That’s a little bit different because it’s due to pipes and distribution systems. It’s a little bit of a different type of contaminant, it’s picked up after drinking water treatment, so it’s largely an infrastructure issue. Cities have been dealing with that, and there’s been a lot of attention placed on that. 

People probably don’t really think too much about contaminants in their drinking water, especially if you get your drinking water from a public utility. People might take it for granted and think that, well, since the drinking water is coming out of my tap, it’s from a public utility, it’s perfectly fine, it’s perfectly safe. I think a lot of people don’t give it a second guess. However, we do know that there are a lot of these unregulated contaminants, and the regulations that we do have in place, a lot of them haven’t been updated based on the most current science and what we know about potential health effects.

So a lot of them aren’t as protective as we would want them to be as well. Nitrate, for example, should be a lot lower than what the legal standard is currently to protect against the additional risk of several different types of cancer and reproductive effects.

Schulz: Yeah, let’s zoom in here. I actually briefly hopped on your website and looked at my local provider, and was a little surprised at what I saw. 

Stoiber: Yeah, the tap water database is a good resource. It’s the online tool, anybody can use it to look up their drinking water.

Schulz: I am curious to know a little bit more about why EWG makes the differentiation between legal and safe.

Stoiber: If you look at the tap water database, there is an EWG standard for drinking water contaminants, and we compare that to the legal limits. What we would like to see, what the gold standard would be, those would be limits that would be purely based on protecting health and what we know about how these contaminants can harm your health. Those are largely based on either state or federal agency findings. 

Many of them are based on California’s public health goals to protect against cancer. They are often quite lower than what the federal legal limits would allow. Either based on California’s public health goals, or EPA’s IRIS assessments, or often other state agency findings, sometimes based on our own derivation, based on recent scientific literature, findings. But they would all be what would be ideal to protect against public health and to not allow the additional health harms and risk that is associated with some of the contaminants that are in our drinking water. A lot of these legal limits are not as protective as they could be based on what the current scientific findings are.

Schulz: What is PFAS? And more importantly, based on what we’ve just been talking about, why is there so much focus on it now, given the fact that it’s one of the many contaminants that we should be looking at?

Stoiber: PFAS, I think people are becoming more aware of. I think it is becoming more of a household term. PFAS is actually a family of thousands of different chemicals, and they all share the same common characteristic. They all have these carbon and fluorine bonds, they’re highly fluorinated chemicals. It’s these really strong bonds that give them those properties of being stain resistant, water resistant, grease resistant and that’s why they’re used in so many products.

And it’s those strong bonds that also make them really persistent in the environment. They tend not to break down, they end up cycling in the environment, and they ended up in drinking water, soil, air and then we’re exposed to them. 

So people may know them as the Teflon chemicals. They’ve been used for decades now. Some of the legacy, longer chain PFAS chemicals were voluntarily phased out, but they’ve since been replaced by other very similar chemicals that are just as persistent. We have been working on this issue for decades now. 

As I mentioned before, the federal drinking water regulation is a long time coming. We have known about drinking water pollution for quite some time, and the more that we test for it, the more that we’re finding it. EPA is coming out again with another national testing data set, but it will take some time for that data to be available. That’s why we continue to do these smaller testing projects, just to get more results out there and to show that this contamination is quite widespread. 

We have been talking about them for a long time, but now I just think more people are talking about them. I think the message is getting out there that the contamination is so widespread. And in the most recent USGS report, almost half of the taps in the U.S. have detections. Also people are talking about them because of the new MCL proposal, and what that means for our drinking water.

Schulz: So what exactly is the proposal, if you can give it to me in layman’s terms? 

Stoiber: There are two proposed MCLs and then the hazard index. So the MCL will cover six different types of PFAS, it’ll cover PFOA, PFOS and four others as part of a mixture, and a hazard index will be calculated for those. So for the PFOA PFOS, the limits would be four parts per trillion, and that’s largely based on detection limits and how we can reproducibly and reliably detect PFAS in drinking water. 

But in the EPA’s proposal, it’s the MCL-G, which is the health based limit that we want to be working towards. That is different from the legally enforceable MCL. That’s the four parts per trillion. But actually the goal would be zero, because there’s no actual safe limit of these chemicals in your drinking water. So the goal is zero, they are linked to cancer. But what we can legally enforce because of those detection limits, that’s going to be four parts per trillion.

Schulz: One of the things you mentioned that EWG does is that they work to identify, what commercially available resources there are for people to utilize in their households. Are there any filters that you would recommend people use? Or anything that people can do?

Stoiber: Starting with the filters, we do recommend filtering your drinking water at home. Either granular activated carbon or reverse osmosis type drinking water filters in your home can greatly reduce PFAS exposure. Filtering your drinking water is a really easy step that you can take to reduce these known exposures, so that’s why it’s recommended.

Activated carbon filters are going to be a little bit more cost accessible, compared to reverse osmosis, which would be a little bit more expensive and a little bit more involved in terms of plumbing. You might need to do a little bit of plumbing to install that under the sink. The thing to remember with the carbon filters is that they need to be changed on time, because if you don’t change out the filter cartridge, they won’t really work all that efficiently. So we do recommend absolutely filtering your drinking water, that’s a great way to reduce exposure. It will take some time for the MCLs to be finalized and to be enforced, so this is one way that people can do something. 

But absolutely recognizing that this, the mental burden of having to figure out what filter to buy, the economic burden of, now I have to purchase a filter and use this, this shouldn’t be placed on individuals or the community. Absolutely, recognizing that it should be the polluters that were originally responsible for this and that have profited so much over the last few decades, it should be the polluters that pay to fix this.

That cost shouldn’t be the burden of that community that now has to deal with that existing pollution from here on out. That’s why the long-term solutions, you know, those are short-term solutions, but the long-term solutions are having federal regulations in place, and of course, overall, reducing as much as possible the use of these types of chemicals in commerce, because they as a result of manufacturing, and releases from manufacturing, use and disposal, they find their way into the environment, and they tend to stay there. So reducing them as much as possible is really the way to go.