PFAS Unpacked: Experts Answer Questions On EPA Rules, Funding, Treatment, And More

For years, per- and polyfluoroalkyl substances (PFAS) have been a top concern for water treatment plants (WTPs) and wastewater treatment plants (WWTPs). Now, with U.S. EPA rules in place regarding some PFAS and enforcement due to start in 2029, many WTPs are finding themselves with a growing number of questions regarding how to treat these chemicals, the potential costs, and much more. To help get those answered, Water Online hosted an Ask Me Anything session on the legal, engineering, and practical treatment of PFAS. To aid attendees, Kevin Westerling, chief editor of Water Online, brought in three expert panelists: Ken Sansone, Senior Partner at SL Environmental Law Group; Kyle Thompson, National PFAS Lead at Carollo Engineers; and Lauren Weinrich, Principal Scientist at American Water.

In terms of drinking water, what does the new regulation entail? What are the maximum contaminant level (MCL) thresholds and when will they be enforceable?

Thompson: The limits in the rule are 4 nanograms per liter (ng/L) for PFOA and PFOS, and 10 ng/L for PFHxS, PFNA, and Gen X. And then there's a Hazard Index, which is an equation where the latter three that I just mentioned are each divided by 10 and then a fourth one, PFBS, is divided by 2000 ng/L. Add that all up and then sum of the fractions is supposed to be below one.

How did EPA come up with their MCL levels?

Sansone: Not to defend EPA, because I know that these regulations are very aggressive and they've put a lot of utilities in a tough spot, but I think this is the continuation of a trend that we've been seeing. Particularly with state-based MCLs, the goal has been to set these very close to the detection limit. It reflects to some extent what members of the public expect when they've heard all of this bad stuff about PFAS over the years. They don't want to hear, “There's not too much of it in your water.” I think they want to hear, “There's none of it in your water, effectively.” And I think the regulations reflect that. That’s the practical side of it. From a legal standpoint, the EPA went through the process that it always goes through when it sets drinking water standards and that state agencies go through, and that's a fairly demanding process. But ultimately these standards are set around the idea that you'd want to prevent one more case of cancer in a population of a millions. So, when those are your standards, you're going to end up with some pretty tough numbers.

With the levels so low, is there a concern for false positives?

Weinrich: If you're considering the methodology that EPA has written out under the unregulated contaminant monitoring rule, or UCMR 5, that is the lowest detectable concentration of a contaminant that's considered achievable by the laboratory based on a 95% confidence rate and the national laboratory capacity to reach and achieve that using specified analytical methods. For PFAS in drinking water, that could either be EPA Method 537.1 or 533. Based on the established methods and laboratories that are able to comply with those limits, overall, there is a lot of confidence in that method. It's well defined what those confidence limits are, and these labs have the ability to use every advanced analytical method using LC-MS in order to measure these compounds at very trace levels at the ng/L points. So based on the method development throughout the years, the detection limits have been reduced because of improved capability.

Is each state regulating PFAS the same? There seems to be large differences.

Sansone: What we've seen with PFAS was a period starting in about 2019 or 2020 of individual states coming up with their own regulations while the EPA continued to work on this. Of course, when the EPA finally came out with its own drinking water standards for PFAS, those were lower than the ones that had been in place up to that point in any other state. Those will be the regulations that everybody will have to follow. I would not expect any states to try to impose more stringent regulations than EPA has. Of course, states are free to do that as a legal matter; but, as a technical matter, we're getting pretty close to what can be reliably tested for. So, I don't see many states trying to go below 4 parts per trillion [NOTE: same as 4 ng/L], which means that's going to be the law of the land, as it were, for PFAS and drinking water going forward.

Are there further regulations on PFAS likely in the near future?

Thompson: Yes. A couple come to mind. The EPA has said that they're going to put some kind of rule on what landfills can discharge to wastewater collection systems sometime this year. There’s not a lot of detail on what that might look like, whether it be a quantitative limit or just a best practice. The EPA has also said they're going to do a human health-based ambient water quality criteria for PFAS. That's a rule on PFAS and surface water. At the federal level, it's a recommendation, but that could impact what states choose to put in NPDESs [National Pollutant Discharge Elimination System permits] for wastewater in their states. So, we could see an effective rule for PFAS and wastewater effluent in the future. And then the EPA is also working on a risk assessment for PFAS and biosolids, which is supposed to be completed by the end of this year. That wouldn't lead to a limit on PFAS and biosolids right away; there would be time for review and public comment and all that. But once that risk assessment is complete, we could be looking at a limit on PFAS and biosolids sometime by 2030 or so.

How will the Supreme Court's decision on the recent Chevron case affect the EPA’s ability to classify substances as hazardous under CERCLA?

Sansone: What was called by lawyers and courts “Chevron deference” is really a way to interpret statutes. The idea behind it was when Congress gives authority to a regulatory agency and there are questions about the limits of that authority under Chevron, courts would defer to the agency's own view of their authority. And now that Chevron has been overturned, courts are no longer going to do that. They are going to read the statute and decide for themselves without giving any benefit of the doubt to the agency, whether the agency is acting within its authority. Congress has given EPA what we call express authority to set drinking water regulations, classify hazardous materials, hazardous substances, and so on and so forth. That's not really ever been in serious questions. So, I do not expect the death of Chevron deference to really have any effect on what EPA is doing. When it comes to PFAS, EPA is acting within its clearly delineated authority. Now, all said, the recent Supreme Court decision overturning Chevron is part of what some folks see as a trend toward decreased judicial deference toward agency decision-making. If we kind of look at it holistically like that, then there may be reason to think these regulations are going to get a higher degree of scrutiny. But I think that remains to be seen. Obviously, there are pending legal challenges already to the EPA’s MCLs for PFAS and drinking water.

What should consumers do to mitigate their own PFAS exposure? And how should water utilities approach customer outreach?

Weinrich: This is something that we've been focused on at American Water, which is reaching out to customers. I mean, we'll get to that in a subsequent question, but to start, what can everyone do? Number one is understand where in your life and in this modern lifestyle PFAS is used and in what kind of products it's used. There's a lot of great information out there. We have some resources through the Water Research Foundation Project 5124, which is publicly available and which provides guidance not only for your customers, but for your staff and your utility. And it gets to the point of exactly that question: what can people do every day?

A lot of times we say to vote with your wallet, understanding what materials you may be purchasing, whether it's raincoats or ski jackets that have those water repellent features. Look for alternatives and companies that have committed to removing or reducing their use of PFAS. As we know, PFAS is really great in terms of chemistry for repelling water and liquids and being stain resistant. So our clothing is definitely something that we can look for materials made without PFAS. Same thing with materials in our households. Stain-resistant carpets have PFAS present. When you think about your contact with couches and other things that are stain resistant, if you are in the market for something new, educating yourself on those manufacturers or suppliers that aren't using PFAS and really putting an awareness to what outside of drinking water are. One of the resources for finding those companies that are listed is a website called pfascentral.org. There are a lot of great resources there for finding those manufacturers that have committed to reducing PFAS.

We've done a lot of work in the drinking water industry. I think we're very proud of all of the testing and method development and understanding of PFAS not only in drinking water, but as it moves through the environment. But water isn't the only source of PFAS that we may come into contact with. So, how can we make choices to overall reduce other ways of exposure? Some food packaging, of course, will contain PFAS. Understanding the exposure route is another way to educate and inform ourselves and then make those decisions in our day-to-day lifestyle of how we can reduce some of that. Your water utility may have a lot of resources on their website or social media. Go to those trusted sources, whether it's your local health department, your water utility, the EPA and CDC, or anywhere you can get the right information that's been based in science and vetted and is in the context of the kind of questions that you're trying to find answers for.

Thompson: If I can just chime in on that a little bit. There have been a large number of studies finding that the majority of people's exposure to PFAS, about 80% to 90% of the PFAS exposure, comes through food, not water. And then there's also a lot of studies on how much PFAS is in this or that food and different studies find different exact numbers. But the general overview is that there's typically more PFAS in red meat, which makes sense as you think about the general principle of bioaccumulation of chemicals up the food chain. So, by and large, the number one single thing you can do to reduce your personal PFAS exposure is probably to go vegetarian.

Can PFAS be removed from the human body? If so, how?

Thompson: There was actually a recent study that came out that looked at over 200 Australian firefighters. Firefighters are a group of people who may have relatively high PFAS in their blood from the PFAS in firefighting foam. And they looked at firefighters who participated in blood drives versus those who didn't, and they found that donating blood can actually extract the PFAS remaining in your body.

What PFAS elements are the regulations targeting — for example, short- versus long-chain?

Weinrich: If we just consider drinking water, there's six PFAS that are included in there. Typically, more on the long-chain side. Those considered long-chain have had the most research in terms of the health impacts. And when we talk about long-chain versus short-chain, PFNA is another long-chain compound. Knowing that there are impacts on human health from long-chain compounds over time, there's been a drive to replace those. So, you may sometimes hear the term short-chain or replacement PFAS. Those are the ones that are manufactured in order to do a similar job in terms of those chemical properties we were talking about, but hopefully not be as bio-accumulative and long lasting. Often that leads to some shorter chain or replacement compounds such as Gen X, a replacement compound that is currently regulated. As we learn more and more, we get a better understanding of how these individual chemicals can impact human health, but then also understand what the trade-offs are in terms of treatment.

What is the status of the liability against the manufacturers of PFAS?

Sansone: There have been many, many lawsuits — thousands of them — that have been filed against the manufacturers of PFAS compounds and certain products containing PFAS — most significantly, firefighting foam — over the past several years. And these lawsuits have been brought by people and agencies that have been affected by PFAS in different ways — people like firefighters who have been exposed to PFAS and have gotten sick as a result. And then, obviously, by a lot of public water systems that have been dealing with the costs or will be dealing with the costs of PFAS in their drinking water supplies, especially with the stringent EPA regulations that we've been talking about. And these cases have all been consolidated for the most part into this one big proceeding, which is known as a multi-district litigation or MDL. And after several years of fighting with 3M and DuPont, ultimately the process has produced two big settlements that you've probably heard of between public water systems for impacts to their drinking water and both 3M and DuPont.

And these settlements are incredibly significant. They provide billions of dollars in recovery for these water systems, and they're set up like class actions and anybody, any public water system who had a PFAS detection before the settlements were announced (June 22, 2023), can make a claim. In fact, the deadline is at the end of next week (July 12, 2024) and we are expecting to see some recovery from those settlements early next year. So that's great. But this is really the end of the beginning, I think, and not the beginning of the end. These are only for public water systems for impacts to drinking water. The settlements don't assist anybody else who's affected by PFAS or if you’re a municipality that has multiple kinds of impacts from PFAS. Not only are some municipalities operating drinking water treatment, but they also operate wastewater treatment, an airport, landfills, etc. These are all things we've been talking about in which liability has not yet been taken care of as part of these settlements and nor has 3M and DuPont's potential liability to all the individuals who have been affected by this been determined.

In addition, there are many other manufacturers, at least a dozen or so, who made firefighting foam with PFAS in it who have also been sued. A couple of them have proposed settlements with drinking water systems just like the 3M and DuPont deals, but many of them have not. Some of it is tied up in bankruptcy proceedings, so there's a lot of litigation to go, but I think it was obviously a very important moment when 3M and DuPont chose to enter into these settlements with drinking water systems because this is something that they had fought for years and years. 3M is really the inventor of PFAS. They were the only manufacturer of PFAS for decades really, until DuPont got involved in the late ’90s or so. And 3M has indicated that it wants to accept responsibility for this and try to move on as a company. So we will see what that looks like. The devil's in the details, but that's really where we are in terms of liability. We've made enormous progress, but we still have a ways to go.

What is the best way to treat or destroy PFAS?

Thompson: Right now, there are studies confirming that thermal regeneration of the GAC [granular activated carbon] can destroy the PFAS — or, at least, the measured and regulated PFAS — by over 99%. PFAS were chosen for firefighting foams because the carbon-fluoride bond makes it heat resistant. There's a difference between heat resistant and heat invincible, right? So, we can destroy these things if we get them up to around 1,000 degrees Celsius in one way or another. There are studies showing that you can destroy these chemicals with GAC thermal regeneration or incineration. Yet there are some questions because it's a hard thing to figure out at the lab-scale because, for example, with a full-scale system for incineration or regeneration you're going to have afterburners providing an additional layer of high temperature exposure to any chemicals. You have to kind of get out there to these full-scale facilities to do that kind of study.

And there are uncertainties because the way that you confirm that the PFAS have been fully destroyed is to measure the fluorine and try to do a fluorine mass balance. And so, in some of these studies, they've seen the measurable and regulated PFAS go away, but then they didn't quite balance out the fluorine mass. Unfortunately, fluorine itself is actually oddly hard to measure. And there can be sources of fluorine in an industrial environment besides the PFAS that was on the media. And then, even if there are some transformation products that would escape, they are very likely much less toxic than the ones that you're starting with. There's all this research on whether there are better ways to destroy the PFAS with supercritical water oxidation or plasma. My view on it is that we can do this now with incineration or the GAC thermal regeneration; it's really just a question of, can we do this in a way that's lower energy, lower cost, or more sustainable in other ways? And so, it's exciting to see what emerges. But we can destroy PFAS with just good old-fashioned heat?

What is the current requirement for the waste that is contaminated with PFAS once it's removed from the drinking water supply?

Thompson: So, there's a difference between what's required now versus what's done now. The CERCLA [Comprehensive Environmental Response, Compensation, and Liability Act] rule, the national drinking water rule, and the RCRA [Resource Conservation and Recovery Act] rule that have been proposed so far don't specifically require certain disposal methods. But there's the potential for further regulations as well, as we anticipate the EPA’s destruction and disposal guidance, which kind of highlights certain disposal practices as safer in terms of potential long-term PFAS re-release. And so, even though there's maybe not a specifically stated requirement, municipal non-hazardous landfills generally decline to accept spent media for PFAS. Right now, the practice is generally to send that spent media to a Subtitle C RCRA-certified facility, or to incineration, or GAC thermal regeneration that's been approved by the EPA at an elevated temperature. So, that's the current practice.

How should PFAS remediation and mitigation be paid for? Should the manufacturers bear it all or should consumers share the cost as well?

Sansone: That's obviously a really important question. As I mentioned, these settlements with 3M and DuPont are significant. They provide billions of dollars. The 3M settlement alone is between $10.5 and $12 billion, and again, just for drinking water. But obviously, it's going to take more than that to clean up PFAS and drinking water in every public water system in the country, particularly to the 4 ppt standard for PFOA and PFOS. I think everybody who's been involved in the lawsuits or who's been talking with water systems about these issues knows that money is going to need to come from somewhere else, too. And what we're likely to see is a combination of federal and state money, and we've seen some of that already in infrastructure bills that have helped fill State Revolving Funds [SRFs], so that money can be distributed to individual water systems to get going on some PFAS treatment projects. But it's a lot of money.

We'll see how well the federal and state governments are able to do in helping water systems out with this. In particular, the capital expenditures for these treatment plants, even if it's GAC, are almost certainly going to run into the millions of dollars even for a single small well, and that's the money that’s hard to come up with. Obviously, it depends on what kind of agency you are as well. Municipalities, particularly bigger ones, have the ability to issue bonds for these kinds of capital expenditures. But smaller agencies and municipal water companies don't. So, it remains to be seen. I think it's an unanswered question at this point, where all the money's going to come from. We know some of it is going to come from the manufacturers of PFAS at this point, and some more of it is going to come from the government.

Who is getting extensions on the rule and why?

Weinrich: The way that the final rule for drinking water (NPDWR) was set out was slightly different from what the EPA has done in the past, which is establish a rule, then there's three years for compliance, and an additional two years could be requested. I'm assuming that that's what this question is related to — an extension. Because of the feedback that EPA got, part of their plan was to slightly shift this ruling. This ruling actually includes and encompasses the full five years for systems to comply. That's a shift from the prior regulations in which some of the systems could seek approval for an additional two years after their three-year compliance. Because of the need for what we were talking about, with capital planning and implementation, all systems will have the five years [for compliance].

So, there's no need for any extensions to be given because EPA took that into account when they established the final rule. The compliance deadline is going to be April 2029 — again, based on the ruling and the way it is. By April 26, 2029, everyone will have to be in compliance for drinking water.

Are there any potential legal liabilities for utilities related to PFAS if the construction of the new removal facilities is not completed in the recommended timeline?

Sansone: There's a system in place under the Safe Drinking Water Act that effectively assigns the responsibility for enforcing all MCLs that the EPA sets to responsible state agencies. And in most states, that's either part of a state environmental agency or part of a state health agency, or maybe a little bit of both. And my experience in representing clients who were struggling to get into compliance with MCLs is that these agencies try to work cooperatively and show a lot of patience, as it can be very expensive to get into compliance and a lot of communities just don't have the resources; nor do they have alternative water supplies that they could look to if they're dealing with contamination. So, although enforcement actions and fines are certainly within the powers that these agencies have for systems that are not in compliance, they really try to use those methods as a last resort, which I think is entirely appropriate.

Now, the next question of course would be: Well, if we're not in compliance, could we potentially be sued by our consumers, by the people drinking our water? And I think that the short answer to that is yes. However, many states, and I'll use California as an example, do not allow lawsuits against utilities if utilities are in compliance with applicable drinking water regulations. But the corollary to that is that they would allow lawsuits for agencies that are not in compliance and for utilities that are not in compliance. So, we could start seeing some of those. We've started to see some of those already in Connecticut. There have been a couple of lawsuits filed there against utilities, even though they are technically not out of compliance because you just heard the compliance period hasn't even really started yet. I think those are rare, but I wouldn't be surprised if you have systems that are lagging to get into compliance — then you might see some lawsuits like that. But again, there's a long compliance period, so we hope that everybody can do what needs to be done and that the money can be found, but it remains to be seen.

When monitoring for PFAS, what are the best ways to sample if you have two sources of raw water?

Weinrich: Yeah, I think one of the challenges with the new rule is that it affects not only groundwater supplies, but surface water supplies. Often, many systems have different sources that they treat, whether it's seasonal or for other reasons. Part of the guidance is to understand what fluctuations may be happening. That question doesn't specify whether it's groundwater or surface water, but I think part of understanding, number one, what is in your water starting at the plant; and then, what current treatment may or may not remove that; and then, your plant effluent composition. So typically, when you're doing surface source water monitoring, you want to test using EPA methods, meaning method 533 or 537.1, same as the ones that are being used in UCMR5. Some of the data from that can also help inform, but part of it is really understanding the amount coming into your system or your treatment plant. Do you shift those supplies? What may be influencing those concentrations upstream? If and when those limits seem to be elevated, will there be a risk for not complying with the current drinking water regulations? It's all about data collection, sampling, and system insights.

From the literature I've reviewed, the levels of PFAS in human serum dropped approximately 50% between 2000 and 2015. Has this trend continued?

Thompson: I have seen a 2023 study where they plotted out that curve all the way through 2018 data. And not surprisingly, that downward trend of PFAS in human blood did continue that additional three years. And, as mentioned before, there are studies showing that 80% to 90% of human PFAS exposure is through food. So it's likely that that drop in PFAS and blood has been largely due to phasing out of PFAS and food contact material. But unfortunately, that doesn't really factor into the way that the EPA calculates these MCLs. As part of the MCL calculation process, the EPA sets the limit based on 20% of the safe dose coming from water, but that's not based on 80% coming from other food. That's just a default assumption that they always do. It's not based on the overall risk assessment or the overall source of the majority of PFAS or chemical risk. It's more based on a philosophy of the drinking water industry doing their fair share. So, that definitely makes the case that having your PFOA or PFOS limit from 5 nanogram per liter to 4 nanogram per liter is probably going to have a very small impact on your PFAS exposure compared to other sources. But that's not how they calculate the MCLs.

What is happening with farmers that have spread PFAS-laden fertilizer derived from wastewater biosolids?

Sansone: It's a problem in places where that's happened. I think probably the clearest example is in the state of Maine, which has a very important dairy industry, and where it was a pretty common practice for dairy farmers to use a couple different things as soil amendments that had PFAS in them, such as a product called fly ash, which was generated by the paper mills in Maine, but also biosolids from wastewater treatment plants. And because of concerns over the contamination of this pasture land, Maine has taken a very aggressive approach when it comes to PFAS through several different avenues. But in particular, Maine has just banned the use of biosolids for land application. And that has obviously driven up the operational cost for wastewater treatment operators in Maine. And there's about half a dozen other states right now that are looking into the problem of PFAS and biosolids in one way or another.

And there were some other high-profile incidents. There was one in Texas, for example, where there was biosolids used on a farm and the levels of PFAS that are in the soil and the water there were just astronomical. And the farmer is saying that his livelihood is completely ruined as a result. So, this is sort of what I meant when I said earlier that this is only the end of the beginning when we're sort of figuring out everything that’s going to need to be fixed in some way because of PFAS contamination. And we've already heard about PFAS in red meat. One of the ways that it gets there, obviously, is through the consumption of animal feed that contains it. And that animal feed was grown somewhere where it was taken up. So it's a vicious cycle, and I think we are likely going to see more cleanup that's required and more money that needs to be spent on the problem of PFAS and farmland. And I think initially that's going to fall pretty heavily on wastewater operators.

Thompson: If I can chime on this question, too... I know for one of those, the farms affected in Maine, they received biosolids from a wastewater utility, but they also received pulp waste directly from a paper mill that had been using PFAS. And since this was back at a time when PFAS wasn't an issue that people were aware of, the methods weren't as developed yet. Nobody actually measured the PFAS in the biosolids or the paper mill waste at the time. So, I do feel it's maybe a little unfair to assume that the PFAS at the farm was originating from the wastewater agency and not from the paper mill. And there's kind of similar scenarios going on at other locations, and there was a study in Arizona that compared different farms in the area that had or had not land applied biosolids as well as had or had not irrigated from a river.

And the PFAS in the soil that had received biosolids was negligibly different from the control soil. If anything, the irrigation water appeared to have been a more major source of PFAS. So, while there is PFAS detectable in virtually all biosolids — and I think that's an important issue and should be reduced through source control to the extent possible — just because there's PFAS detected on a farm doesn't necessarily mean it came from the biosolids. Hopefully, these sorts of considerations will be taken into account moving forward.

What is the state of wastewater regulations for PFAS?

Thompson: I believe there's actually two states now that have banned biosolids land application over PFAS concerns completely. Maine was the first, but just recently Connecticut as well. And then I believe there's four states — Michigan, Wisconsin, Colorado, and New York — that have put limits on biosolids. But the limit, it's more based on what could be achievable through source control as opposed to being based on a full health risk assessment. As far as effluent, I believe Colorado has a limit, they call it translational limit, and they've started implementing that into NPDES permits, but that's the only state as far as I'm aware. And as I mentioned, restrictions could take on other forms. For example, it might not be so much as a rule on the effluent directly as a rule on the surface water. And then states would need to figure out how they want to incorporate that into the NPDES, meaning if they want to just treat the rule for the surface water as the rule for the effluent or if they might take into account dilution or what's achievable through source control.

What ongoing research might impact future PFAS management strategies?

Weinrich: There's a lot of exciting research out there. What we haven't necessarily talked about too much in this webcast is around the best available technologies — GAC and ion exchange. But there are a lot of other options. And what I was going to say is that the best available technologies we have at the moment are not destroying PFAS — we are [just] moving it from one media to another. We did talk about the destruction and disposal of that spent media, but hopefully in the future, with a lot of the technologies that are being looked at now, whether it's, I think Kyle mentioned a few —plasma, UV light, photocatalysis, electrochemical oxidation — some of these emerging technologies are able to break the chains and break it down to the elements and remove PFAS from the environment. Hopefully, that research continues to develop, although a lot of it may still be at bench- or pilot-scale.

I'll also point out that there isn't a lot that we're able to use in drinking water right now. Drinking water has very specific requirements. They have to be NSF-61 certified and approved to be implemented. And that's why we have relatively limited but effective toolkits for removing PFAS from drinking water. As we talk more about wastewater and biosolids and industrial levels of contamination with PFAS that are out there, putting these emerging technologies in place so that we can be able to limit the movement of PFAS through the environment will reduce the amount that's there, and balance the amount of energy used to apply those technologies. A lot of the ones that we mentioned have a lot of energy requirements. So how resource-intensive is it? Those are things that need to be considered in the future for practical implementation, whether it's municipal water and wastewater or industrial users, and being able to apply those technologies.

Part of what also needs to be evaluated are what byproducts of those technologies may form. Or, another way to put it, how effective are they at truly breaking down the PFAS compounds that are present? And I think the one other consideration, too, is will those technologies be able to be deployed onsite or will utilities need to truck off or leverage a transport to a different facility? So that's going to be another consideration. But I think, given the nationwide and worldwide challenge that's here, it does generate a lot of interest in finding ways to solve this challenge of removing it through the environment. Hopefully we have some of those additional tools in the toolkit in the future.

How much money can utilities expect to receive from the settlements that Ken referenced to meet compliance?

Sansone: The settlements use a pretty sophisticated formula to determine, ultimately, how much utilities are going to be recovering. And the formula actually calculates a score for each individually impacted water source. So, whether that's a groundwater supply well or a surface water supply that's coming in at a water treatment plant, each of those is given its own score. And the score is really the product of two sets of data. One is the PFAS analytical data — the historically highest PFOA and PFOS that's ever been detected in that source. And then the other side of the ledger is on the production side. How big is the source, both in terms of its maximum production capacity and the volume of water that it has historically produced over the last 10 years, or technically from 2012 to 2022? And the idea behind setting up the formula that way, of course, was to see to it that more heavily impacted sources that were going to be more expensive to treat because they're bigger — the bigger your well, the more steel tanks you're going to need for GAC or anion exchange; the more water you're producing, the more frequently you're going to need to change out or recharge your media — are allocated the money fairly according to those principles. The tricky part of all this is that those scores that I mentioned are used as the basis for making prorated distributions from different funds within the settlement.

So, the higher your impacts, the more money you're going to get, but you don't know exactly how much money you were going to get. Now there was information that was released in connection with the settlements that allowed some estimating, and that's certainly something that we did for our clients. We have about 250 different clients who were participating in the settlements and many of them saw seven figures. A lot of them saw eight figures or even higher recoveries under these settlements. But, of course, everything is relative. I think everybody understands that these settlements, although significant, are not going to pay for most water systems anywhere near 100% of what this is going to cost in the long run. I think the most useful way to look at these settlements is it's a good way to get started on what the costs of dealing with this are going to be.