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PFAS: Responding to the forever chemical in our drinking water supplies - Episode 1
We really nerd out in this episode as we are joined by Steve Nelson and Ryan Stempski, both from WSB & Associates, to talk about PFAS in our drinking water supplies. There is much to unpack about this complex and important issue, and this is just the first hour in likely several hours of conversation on this topic in the months ahead. Enjoy!
AI Generated Episode Description:
The drinking water crisis nobody's ready for is already here. PFAS, nicknamed "forever chemicals," have infiltrated water supplies across America, and new EPA regulations mandating treatment down to 4 parts per trillion have created a staggering financial burden for communities. This eye-opening conversation with PFAS experts Steve Nelson and Ryan Stempski reveals the true scale of the problem.
What makes PFAS so concerning? The carbon-fluorine bond at their core is virtually indestructible in nature, meaning these chemicals persist in groundwater sources for decades or longer. With health effects ranging from increased cholesterol to cancer risks, the EPA's stringent new limits aim to protect public health—but at what cost?
For a city like Hastings, Minnesota, treating seven contaminated wells will cost approximately $68.9 million to build treatment facilities and about $1 million annually to operate—a $100 million lifetime investment. Using Granular Activated Carbon (GAC), the primary treatment technology, communities must effectively create "parking garages" where PFAS molecules can be trapped. When these carbon vessels become saturated, they must be replaced at roughly $60,000 each.
The Minnesota experience offers valuable insights for communities nationwide. While the $850+ million 3M settlement provides funding for impacted areas in the East Metro, most American communities will need to cobble together federal grants, state assistance, and increased water rates to afford treatment. As one expert notes, "We're all going to be competing for the same resources" as the 2029 compliance deadline approaches.
Whether your community is dealing with PFAS now or will in the future, this conversation provides crucial understanding of the science, costs, and challenges ahead. The affordable water we've taken for granted may soon be a thing of the past. Subscribe now and join the conversation about how we'll protect our most vital resource.
Welcome to the Public Works Nerds Podcast.
Marc Culver:Welcome to the Public Works Nerds Podcast, a Public Works Podcast of the nerds for the nerds and by the nerds. I'm your host, mark Culver. Today we're starting what I hope turns into a multi-episode series on PFAS and our drinking water supply and how we are responding to this contaminant in our drinking water supply and how we are responding to this contaminant.
Marc Culver:Pfas, p-f-a-s, per and polyfluoroalkyl substances I did not practice that well, but I think I was close are a group of human-made chemicals widely used in industrial and consumer products. For their water and grease-resistant properties, they are commonly found in items like nonstick cookware resistant properties. They are commonly found in items like nonstick cookware, waterproof clothing, food packaging and firefighting foams. And, as it relates to our drinking water supply, pfas can enter drinking water supplies through industrial discharges, landfill runoff, wastewater treatment plants and the use of those firefighting foams. Because PFAS does not break down easily, if at all, in the environment, they are often referred to as forever chemicals and can persist in water sources for decades.
Marc Culver:Long-term exposure to PFAS has been linked to increased cholesterol levels, liver and kidney damage, immune system suppression, developmental effects in infants and children and increased risks of certain types of cancer. Recent changes to the Environmental Protection Agency's rules related to primary drinking water regulation have set the maximum contaminant level for six varieties of PFAS in drinking water at really low levels, as low as four parts per trillion for some of those varieties. Today, we're going to do our best to nerd out on this really important topic and a very impactful topic for municipal well for any water supplier. We're joined by two experts that are helping communities in Minnesota deal with this issue and explore options for treating their water to meet these new standards, and I'm just going to back off now and let you guys take a couple of minutes to introduce yourselves. Let's start with you, steve.
Steve Nelson:Hey, mark, thank you. I'm Steve Nelson, director of Water and Wastewater with WSB.
Ryan Stempski:Hey, Mark. I'm Ryan Stemski. I'm also with WSB as a senior project manager. I serve as the Hastings Public Works Director dealing with this very issue.
Marc Culver:Awesome, steve. Why don't you give a little bit of background of you know, not like 20 minutes, but you know a two minute version of how you got into this and a little bit of your background?
Steve Nelson:Okay, Some of my background is I started as a pool boy, believe it or not. But maintaining the chemicals at the Maple Grove Pool.
Marc Culver:Wow, that's way back, yeah.
Steve Nelson:Yeah. So I got into water maintaining the pumps, teaching swim lessons, all that stuff and then got my. Ended up getting my master's in environmental health from KU. Started with a national firm down there, oh Jayhawks huh.
Steve Nelson:Yep, jayhawk Rock Chalk and so I was with the group basically multiple phds and a couple of us with masters and, uh, advanced advanced environmental technology groups. So we were looking at ro. Basically I was going to become an ro expert. You know, ion exchange, gac research foundation, um, you know guidance manuals, beta, beta testing of the different tools they use for that. So all very high end chemistry stuff and I absolutely loved it.
Steve Nelson:So, mark and my spreadsheet it did not say that I was going to come back to Maple Grove, but part of science I didn't factor in was my wife's desired for our kids to be by their grandparents. So, anyway, but so some will allude to how some of that help set me up for that. But what really got me into the PFAS was back in 2016 for the Minnesota Attorney General versus 3M, the natural resource degradation settlement. So did all the heavy lifting for the calculations, the spreadsheets and the writing of that, and that was very. I'll speak a little bit more to how that was helpful in what I do today, but I'll turn it over to Ryan to share how he got into it.
Marc Culver:Yeah, a little bit of your origin story, mr Temske.
Ryan Stempski:Yeah, I've been dealing with PFAS for municipal clients for about two decades now. It started out for about two decades now. It started out in Lake Elmo, one of the areas hit by PFAS.
Steve Nelson:Early on I was an assistant city engineer in that area for that community and I kind of felt like Aaron Brockovich.
Ryan Stempski:To be honest, this was 20 years ago, Without the heels, Without the heels, but I was the young, eager engineer that wanted to go door to door and start to explain PFAS with the Department of Health and what we were going to do about it. So that was back when, in that location, 3M was a partner at the time funding some land and some water system extensions to switch folks from wells and all of those aquifer points of contamination to one municipal water system. So that's where my work began. I moved into serving West Lakeland Township, which is just east of Lake Elmo. The water flows through Lake Elmo to the St Croix River and so West Lakeland was kind of in a hotspot as well.
Ryan Stempski:That's a township or a rural community. Part of our work with the co-trustees of the 3M settlement funds was to switch that private well community to a municipal water system. So that got them to about $180 million of funding to put in a water system. But the township residents wanted to remain rural. So a lot more to unpackage with that story Uh. But that took years to work through and a lot of um, a lot of political stress and a lot of, a lot of turmoil in the community. Then I moved South uh to help uh, the city of Hastings as their city engineer originally, and PFAS followed me down there as well. So with the lowering of the contaminant levels, like you mentioned early on, that brought Hastings into the PFAS treatment game, and now that's what I'm really stuck right in the middle of dealing with in the Hastings community. Cool.
Marc Culver:Well, thank you. And just even going back a little further in your origin story, where'd you go to college?
Marc Culver:I am a badger, you're a cheese, so university of Wisconsin, madison, no matter, no wonder you didn't mention it, ouch, yeah, so. So, yeah, I actually have an issue with both those colleges, cause my son is now a baseball player for Utah, so big 12. Now they're, this is their first year in the big 12. So I, I I have to be anti Kansas and uh, and I'm always anti Badger, but, but there we have a lot of Badger fans that listen to this. I know there was one really big uh Badger fan, julie long, that listens to this. So go, go, badgers. Um, all right, cool.
Marc Culver:Well, let's, let's jump into this now. I mean, this is obviously a really complex topic and, as I said earlier, given the complexity of this topic and the potential impact to communities across the country, you know, hopefully this turns into a multi-episode series and I have a feeling we'll be talking more about this. Today we're just going to kind of focus on your guys' experience with this issue in Minnesota, maybe touch a little bit on what we know nationally towards the end. But, yeah, let's jump in this. And, steve, first of all let's nerd out a little bit on the actual chemistry of PFAS and why we're not going to spend a lot of time on this, but what is it about PFAS that makes it so difficult to break down in the environment?
Steve Nelson:Yeah, so it's the carbon-fluorine bond. It's just a very naturally strong bond. So, going back to that settlement, the $950 million settlement, one of the things we looked at is it's so hard to get rid of and it's so pervasive, so we had experts from all across the nation looking at how it moves, because it ends up in places we never thought it would. So it's slippery, it finds its way through and it does not break down easily. So and then also in doing that, you realize that there's a lot of technologies that can remove it. But we have to realize that in Minnesota, you know we're looking at our natural resources have been damaged and again it's called Forever Chemical.
Steve Nelson:Funny story with that is, um, a company that's foam fractionation. Maybe that's next episode, but like pfos likes to be in foams, so foam fractionation was a method where you see that it naturally gets, you know, into the, into the foam, and there's a company that specializes, uh, in that, from canada, and they were trying to get across the border and the side of their van it says forever, ends, ends. Today and, believe it or not, they got stopped for many multiple hours. I think it went into like a day where they had to come and x-ray their whole van and it's kind of like you know what is that they thought this was a political statement and forever ends today.
Steve Nelson:But we'll get into. You know some of the science, but I guess I just want to preface that it's a lot of because of how mobile it is. One of the big things the attorneys kept trying to coach us the hydrogeologist, the technology people for removal is that we can't only get into the nerdy part of the science, which is very challenging for us. But they have to keep reminding that this is more like a card game. So you need to think of what is the best way to manage any funds, any settlement we get for you know managing PFAS. So what ties into the technologies? There is one of them that I was, you know, probably going to be an expert on if I'd stayed at the national firm was reverse osmosis. But that basically concentrates the stream, so you get 80% treatment but you get 20% reject, so you basically get five times as much PFAS in what you'd be sending to the sewer. And so that was a phrase that kind of we came away with Don't be kicking the can down the road.
Steve Nelson:But that even applies with if you are using like an absorptive technology, catching it on GAC. The same thing applies there Ion it. On GAC. The same thing applies there ion exchange versus GAC. Gac you can, you know, reactivate it. Go, you know, beyond just regenerating, you can actually reactivate it. So there's absolutely no carbon fluorine bonds left, very high temperature, but then you know, your liability for sure has stopped because it's completely destroyed and then you can actually reuse that carbon.
Steve Nelson:So those are, you know, in the there was much that went on to how long is the PFAS going to last if we treat it? Where is it going to end up, all those studies. But a big takeaway was we really need to think of this as a long-term, you know, management of. We have so much funds total to look at, you know, remediating this problem, this damaged resource, and what is the way we're not going to be kicking can down the road in terms of to the wastewater plant in the water or in terms of in a landfill and then ends up in the leachate again or in the air.
Marc Culver:So you know it. What's what's interesting about this? This issue is and we'll talk more about the treatment levels and what does actually GAC mean and some things like that in a little bit. But we've well, 3m has known about PFAS for a long time and they've been monitoring it for a while. And, ryan, this will be good for you to talk about your experience with this and even the 3M settlement and things like that. But my next question here is going to go towards the EPA standard and that why, all of a sudden, are we really freaking out about this? You know, because we've probably been testing wells or we've seen levels, you know, maybe 10, 20, 30 parts per trillion, and we were fine. Maybe 10, 20, 30 parts per trillion, and we were fine. But now, all of a sudden, we're really freaking out.
Ryan Stempski:And why is that? Yeah, that's a great question, mark. The reason in the two decades I've been involved in PFAS is about the similar time where the levels have been in the thousands that we've been monitoring parts per trillion down to the thousandth part per trillion. So you're right, no other chemical has been studied more in those two decades than PFAS. So the emerging science on this is kind of some of that reason and the one answer is epidemiology.
Ryan Stempski:I think the epidemiology has come along so far. We started out 20 years ago testing lab mice and testing animals and getting some of the knowledge and information in health guidance levels. Based on that information Fast forward ahead. The federal government got involved, the EPA got involved and took a more worldwide human approach to their medical study and their epidemiology and started looking at concentrated groups and pulling that information together and seeing all the harmful effects that you listed in the opening of the podcast, and that is where they started to link some of their scientific and medical confidence in the harmful effects of PFAS. So as soon as that emerging science and emerging epidemiology came forward through the EPA, that information was passed along to the states and the states same thing, you know, going through their studies started to put more and more of the science together, and that's why we're at the levels we're at today.
Marc Culver:Yeah, so what happened in April? You know again. You know we're now down to as I started. As I stated in the intro, we're at today. Yeah, so what happened in April? Again, we're now down to, as I stated in the intro, we're down to. Some of these are down to a limit of four parts per trillion, some are at 10 parts per trillion, but what happened in April?
Ryan Stempski:Yeah, so the chemicals that I'm specifically dealing with the long chain PFAS, the PFOA and the PFOS are really those ones that you're talking about, down to four parts per trillion. What happened in April was the comment periods were over for the maximum contaminant levels and that's when that maximum contaminant level of four parts per trillion was issued as federal law by the Environmental Protection Agency, by the EPA Environmental Protection Agency. That level was set most likely or based on, I'll say, the ability across the country to confidently test for PFAS down to that, and that marker was four parts per trillion. I think I read comments of where it would have been set lower, but the EPA wasn't going to set a limit lower than what had reliable testing in our laboratories. It is important to note the state of Minnesota can test to more closer to about two parts per trillion, but nationwide.
Marc Culver:That's why we've seen that four parts per trillion number, and so, now that this maximum contaminant level has been set, what's the timing and the progression of this for water suppliers?
Steve Nelson:Basically it's kind of started a five-year timeframe Is it two years, ryan? To kind of study and three years to implement. And really right now we're seeing in the industry ever since COVID, that what used to take maybe 18 months to get to substantial completion, two years, is pretty much standard now. Another thing I'd think I'd say with regard to the epidemiology and health is what Ryan's done a nice job, and we've been doing that with Brooklyn Park as well. When you have people with questions, um, you want to serve them.
Steve Nelson:But I think as public servants we also, you know, clear as kind, and so I, what we've done in Hastings and what you know we're doing in other communities bring the say yeah, that's a great question, we're going to have, um, the department of health come in and talk and so they can ask. You know your residents can ask the Department of Health directly, because there was some a little bit different approach between Department of Health, like really trying to say what's the lowest level where you still have health impacts. But I think it's it seems like it's most likely to continue that what the EPA sets. You know they have the epidemiologists, they can look at the whole context of cost and health impact and balance that and what they come down with. Basically, you know, as the promulgating agency, department of health is going to follow suit.
Steve Nelson:So I think that's a good thing you know. Avoid the temptation to be commenting like you're an epidemiologist yourself and say you know, as public servants and engineers, we meet these standards. So now we have the five years to do that and, ryan, you can speak to this, but I think the timeframe is important. And back to the card game again is there's going to be limited funding available and getting the money is key, and I think beginning some of those studies up front is very helpful. Ryan, you might want to speak to that for what Mark is.
Ryan Stempski:No, just a little bit. Furthermore, on the question of standing up treatment to get down to four parts per trillion or less, is that five-year mark? The two-year mark is the testing going on right now. So what Department of Health has deployed their? Is getting corn, quarterly, running annual averages, so QRA, so getting what we need another acronym, but exactly, exactly, but, but to get those tests. So there's not a spike or or misrepresentation of a community. They want to grab your averages over four quarters per se, and so that's what's going on right now. In two years is really when those tests should all be gathered for communities, and then, if you're over those limits, you'd be required to put them out in your consumer confidence reports, and so that's when you're notifying your publics officially, you're putting in your CCR. That's when you're notifying your publics officially, you're putting in your CCR, and then you have until 2029 to stand up, whatever treatment or different source that works for that community and have those limits delivered less than the four parts per trillion.
Marc Culver:So just a little further on your timeline question, yeah, and you know, for for a community, and what I'm seeing, and I'm experiencing this in brooklyn park, um, more and more communities are going to start seeing elevated levels of pfas and and I think it's going to and you mentioned it earlier this, this stuff is moving through our groundwater system. Um, it's transporting it's, it's it's going from point A to point B, it's crossing different areas. More and more communities are going to see this going forward. Just because you test negative now doesn't mean in 10 years, you aren't, so it's. I think we really have no idea what the magnitude of this is really going to be in that five years, let alone 10, 15 years forward.
Marc Culver:So, related to that, like, if I'm a community, that's, you know, currently testing below the limit, maybe the limit moves, you know that's a possibility too. But all of a sudden I get to a point where I'm starting to test above the limit and you know I'm going to say, wow, I better start studying this, better start doing, you know, get a report together, get some options together. So if a community woke up tomorrow and realized wow, we've got elevated levels, we better start doing something with this On a normal basis, actual implementable schedule, how long do you think it's going to take for them to start to actually have a treatment process in place?
Steve Nelson:That does tie in on if you're going to have to do the study or not. I mean Oakdale, for example. I did the second Oakdale plant, small plant just associated with well seven, the RFP for engineering services.
Steve Nelson:Between the time I responded to that and had the plant up and running was six months so there's nothing extraordinarily complicated necessarily about this gac treatment, especially with our 3d models and you know everything we have and and the design tools and design aids, um. But that being said, they had funding, so they had some of that three settlement money. So to get in line for that funding, to help you have that, we found that it's helpful to do the study first and because it's the same co-trustees you know that was involved in 3m settlement, that was involved in the 13, 17 actually east metro communities, with some townships kind of agreed on those. What's the standard things? You look okay.
Steve Nelson:Alternative source surface water. Develop your own surface water, plant surface water. Connect to minneapolis or saint paul as a consecutive wholesale purchaser of water. Thirdly, alternative aquifer can you drill in a different place? Where is it flowing? Or go to a deeper well, mount simon, which currently there's a motor moratorium on, but there is some indication that some allowance that would be a tool in the tool belt for partial solution, um treatment at the site or treatment at a central treatment plant. And again, we have to remember that it's the community up to the communities involving them what they think is a big thing.
Steve Nelson:That was discussed during the 3M settlement was blending and it kind of moved away from that for the settlement dollars. This is no. That's different, though, because their natural resource was damaged. It was damaged by 3M. We can tell by the fingerprint of the distribution of the types of what are there 30,000, thousands and thousands of PFAS constituents but you can tell by the distribution of you know what are there 30,000, thousands and thousands of PFAS constituents but you can tell by the distribution of those. Is this similar to what's associated with 3M? Down to, you can say kind of the DNA. If the glove fits, you must acquit. If you see that exact molecule, you know for sure and Ryan will probably be able to speak to that in a second that it was indeed 3M contamination.
Steve Nelson:But doing that same study that's been proven by all the co-trustees and approved by this is a Good Approach, kind of following that up front. Getting study dollars to do that really puts you in a position where you can say well, before we give you construction dollars, have you done this? Yes, we had our engineer consultant look at that in terms of groundwater flow. Did you look at alternative source? Yes, did you look at treatment at the site? Did you look at blending? What have you decided on. If you're ready to go, you might be able to have the winning story that you're funding people are looking for to say, okay, let's, these guys are kind of shovel ready. If you will, let's go ahead and provide them construction funding.
Ryan Stempski:Yeah, yeah one thing to mark, to go back on to your point of how this may impact communities across yeah, yeah of the state of Minnesota. So we've got to rewind back a little bit before April, back in January of 2024, we had health-based guidance issued by the Department of Health. Now that guidance is looking at health impacts and health impacts alone, not feasibility, not impact, like EPA took into account. Some of those levels are even more alarming as far as what they are, I think for PFOA it's at 0.0079 parts per trillion, for example. So I think to your point is if you can detect it in your water system, you should be having those conversations and thinking about what might be coming. Because that is my concern right now is not only the EPA, but what is our own state doing and what have they published? And they have published guidance. We have made decisions on PFAS for the last couple of decades based on health-based values, which makes sense.
Marc Culver:Right.
Ryan Stempski:So we need to keep that in context with the conversation. As far as timeline, I think Steve gave you a great example of when you have funding and you need to move quick. In Oakdale, what he accomplished there was amazing right Six months. Same thing what I'm doing in Hastings kind of the flip side right. We know we have the problem, we want to work towards the final solution, but we also want to get the funding in place. So we're trying to connect hydrogeology across the Mississippi River and looking at complex formulas and equations of how do we connect one of the four disposal sites known in the East Metro. And that's our story in Hastings. Other communities might have different dump sites or different polluters that they're looking at, but it can take time. We've been at it for over two years in Hastings trying to ask the right questions, get the right people involved to find these connections out, and today we've connected one of what I'll call seven wells that have contamination.
Marc Culver:We keep touching on trustees and 3M and this, that and the other. So, ryan, why don't you give us a little more background on two? What are we actually talking about here? What happened? Who sued 3M, or what was the process that created this fund for communities to use?
Ryan Stempski:Yeah, sometimes I forget there's a world beyond the East Metro, right, right, yeah, so this is kind of an East Metro terminology that we're seeing. East Metro is kind of paving the way for setting some examples of how to deal with PFAS and how to fund PFAS. So that's why we keep coming back to the East Metro and the 3M settlement funds. Really, what this was, it was about a 10-year negotiation between the state of Minnesota and 3M on disposal sites in the East Metro. So in 2018, there was a settlement put together. I think it was about $700 million, I forget because attorneys needed to get paid first $950 million, but that $50 million went immediately to the attorneys.
Steve Nelson:Yeah, we should have charged higher.
Ryan Stempski:Yes, of course, so we can all learn lessons from attorneys, I think all said and done, I say $700 million, $800 million I forget the exact amount after legal fees but that was the amount given from 3M to what was called the co? -trustees. The co-trustees are made up of the Minnesota Pollution Control Agency, MPCA, and the DNR Department of Natural Resources. So when we say co-trustees, those are the two entities that have been given the authority of how the funds will be invested, how they'll be spent, how they'll be distributed and created policies around that. So we did have a work group formed back, in alignment with the 2018 settlement, to help guide those co-trustees, but really, at the end of the day, that's, those are the decision makers. So that's why I keep coming back to the co-trustees of the 3M settlement.
Marc Culver:And so when you talk about, you know telling Hastings story and trying to prove, you know the, the, the river, water transmission and this, you know crossing the river and that you're trying to do this so you can prove that this is 3M's chemical, so that you can get money out of that fund, so that the co-trustees will say, yep, this qualifies, we're going to pay for your treatment, right?
Ryan Stempski:Absolutely. The 3M settlement funds as you can imagine, we've been going at it for a while, since 2018, are projected to be fully spent. So that doesn't mean everything. Every dollar has been issued, but projects are planned and we see the sunset of those funds. That doesn't mean that East Metro is done at that point. There's actually a 2007 consent order with 3M. So if you're still above MCLs or health guidance levels, you still qualify through the co-trustee process for additional funds above and beyond the original $800, $900 million that was given. So there still is a process in a way.
Ryan Stempski:So it's very important for communities in the East Metro, if you can connect to these 3M settlement funds, that you do, because planning is covered, design is covered, construction is covered and 20 years of operation and maintenance is currently covered per the conceptual drinking water supply plan in the East Metro. So there's a guiding document of how we do this. So, yes, it's very important that you try to connect if you can. And so Hastings being sort of that last municipality connected to the East Metro, with just a river between them and the remaining cities, the neighboring cities, just proximity alone. Right first community, down river of where PFAS was made, a lot of deep fault lines cut through the east metro, right through hastings, right underneath the river into these deep aquifers. So a lot of things that were aligned, uh that we started asking those questions and saying, uh, why, why, why isn't hastings being traded like their neighbors?
Marc Culver:yeah, and that's where we're at. And when we're talking about 3m here, you know they. They have some very famous products like Scotchgard and what else that has this PFAS chemical in it that they've been producing for 50 years right?
Ryan Stempski:Oh, I think it's endless. I mean I've heard of cosmetic products, dental floss, popcorn inside of popcorn, microwave popcorn, liners, I mean you name it is that but those aren't all 3m products either, right, or does 3m have a hand in uh and all those?
Marc Culver:because they're like, dupont is also a very famous uh or well-known producer, pfos, um and there are a lot of other uh producers for weatherproofing, clothing and this, that and the other, so even the fire foams. I'm not sure where that comes from, but the point being is, these things are being produced. I mean, minnesota is a hotspot right now, but there are products and such that are being produced across the country that are using these, and I believe they're working on identifying, you know, super fund status so that similar pots of money can be set up for cleanup and make the DuPonts and other companies responsible for those as well. So did you have something else you wanted to add, steve?
Steve Nelson:I was just going to say that, even if you're not, you know, in the 3M, I think that you can learn a lot from that example Number one you can learn that that was the absolute top experts in the country, if not the world, that were doing that groundwater modeling. And he said, yeah, hastings is not in that because it can't get there. Well, they're wrong, because we found the exact just recently. Well, five became part of it because they found again that specific molecule. Another thing is it's kind of the same if you're doing a study because that's been established as what makes sense. You know the alternative sources river water, this, that the other, blending, not blending. That same line of thinking is what they're going to want to see you go through in a study. Thinking is what they're going to want to see you go through in a study because it's still mpca. That will most likely have you know funding for you know preliminary study and design. Still department of health, those people are going to have to buy off on funding. You know applications. So, um, and the agreed to life cycle cost was another kind of takeaway there. That another reason to get look at this as a card game as much as just, you know, the nerd science side of it is that really getting in line for that funding because it's not going to last forever. So when I was sick we were successful in that lawsuit and, um, you know, state of minnesota won the settlement. In my engineering nerdy mind I said we're set Because every engineer we had factored in there that does engineering can get their 20 plus percent. We can have complete 30 years of GAC replacement costs and that is. We'll maybe talk about that in a little bit, but that is the tail that now wags the dog. If your water costs are primarily due to pumping now and you're kind of prioritizing which wells you pump based on pumping costs, electrical costs that will completely change. If you have GAC it becomes GAC replacement costs and making that GAC last. So those funds we're doing.
Steve Nelson:St Paul Park, for example, Oakdale was replacing every year and then it went to every two years. Example oakdale was replacing every year and then it went to every two years. St paul park because they've got a little bit lower concentrations and because the the trigger that mpc is looking at for um, you know when replacement makes sense has been changing, used to be, if you get any detection of pfba, which is the most prevalent molecule coming through your lead vessel, you replace. Then it went to okay, if what's coming out of the filter is 50% of what's going in. That is time you replace and that's kind of moving. What makes sense? Um, you know, get thinking, thinking about that. Um, in terms of those life cycle costs for the St Paul park, we're talking about replacement in six years, so they've been in service about five years. A year from now, they think all the funding for replacement that is available for O&M cost replacement will be, uh, completely used in two years.
Ryan Stempski:Well, that's far less than the third year's anticipated, yeah, so One thing to mark, to maybe nerd out a little bit on your question of 3M and DuPont and others that make PFAS. There's a way, there's a chemistry that can be done to kind of determine where these PFAS are manufactured. So that was one thing that was done in Hastings. Electrochemical fusion is the way we can determine if it's linear versus branch chemistry, and that allows us to determine how these PFAS molecules were fused and made. And so you ask a good question about well, there are others, and yes there are. So, but just know there's a test that can be done to try to understand where your manufacturer might be from.
Ryan Stempski:And also on the national level you speak a little bit about, you know there's a class action lawsuit going on with 3M and DuPont where communities could opt in or opt out of that if you were impacted. So you could run a calculation. I'm not sure where we're at on the deadline there. If you didn't opt out. You opted in. But there was a process there that folks may be familiar with in your communities that also started to acknowledge both the 3M and the DuPont responsibility. I think that was more related to AFFF, but that's a whole segment on its own right.
Marc Culver:Yeah, and then we get into the legal. Then we really get into the Aaron Brockovich's and Pelican Brief and all these other legal movies where we talk about. You know the pros and cons of class action lawsuits and you know the pro is you join a group, a big group, you're first in get the money. The con is that money is split up amongst a lot of different people and you lose out on the opportunity and then sue them later if your costs go up or you find something else. So I'm no attorney. This is not legal advice. That's a different podcast, I'm sure. But yeah, some interesting components of that we keep. You know we've talked about the size of the original settlement, how that money is kind of getting used up, blah, blah, blah. Let's talk about the actual magnitude of this. Ryan, use Hastings as an example. How much are you planning on spending on treatment facilities and maintenance costs, ongoing costs for this for Hastings?
Ryan Stempski:Yeah. So again, not every community is going to be impacted the same Right. Unfortunately for Hastings, they have six wells currently and a seventh well planned in 2026 per their comprehensive plan. So all seven of those wells are over the four parts per trillion we've been speaking of. So that's an entire aquifer that doesn't have a good resolution but for treatment.
Ryan Stempski:And so in their situation, after looking at the feasibility study Steve alluded to looking at all options available to them the most feasible, and really only feasible, option was treatment. That treatment is estimated to cost $68.9 million to build a decentralized system or a system with three treatment plants in the built environment of Hastings. The O&M cost, once those treatment plants go online, are estimated at about $1 million per year. So we kind of talk about it in Hastings as a $100 million problem, just because, if you add the 70 million plus 30 years on, m is kind of what we're looking at for a life cycle. That's a hundred million dollars to that community. Hence the reason why they're looking under every rock belt and suspenders on the funding task at the capital, at the federal level, 3m settlement, as we mentioned already, and water rates. So everything's on the table. Every application for grant funding has been submitted.
Marc Culver:Yeah, and if we just like project that, and obviously we keep talking about this East Metro and if you're not in Minnesota and you're listening to this, we're talking about the East Metro, the Twin Cities area. A lot of the communities there are impacted and we're starting to find other communities that aren't 3M communities necessarily. Brooklyn Park is a great example in the northwestern part of the metro area and a couple of their wells are starting to test positive for PFAS and at levels that would be above this the MCL here and so we've got one. Well, that's offline because we just don't want to deal with it right now and Steve is working very closely with us, spending many hours in Brooklyn Park working with us on this kind of a feasibility study as we look at what options do we have? How much is treatment going to cost? And that's one community and we're probably looking at a similar number $70 to $100 million between building the thing and operating it over a 30-year period. Yeah, now talk about our neighboring communities, because if we're starting to see this, that's just going to keep flowing. You're going to have another $100 million, another $100 million it's. You know, the magnitude of this is just really alarming and I don't think in Minnesota. Here it's like our legislators are aware of this issue, like they know it's a problem. They clearly are aware that this issue, like they know it's a problem, they clearly are aware that this is not this is a dangerous, unhealthy chemical to be in our system, all of the impact, health impacts and everything, and they're throwing money at it. But they're throwing money at like 5% of what they should, what we really need in order to help these communities long-term to do this. Otherwise, our water rates are going to triple over time in order to deal with this. And it's interesting because if you live out West, in California and Colorado and in those states where water is so much more of a rare commodity, you're paying high numbers for water and we're so used to cheap water and available water and good water. And that's going to change. That's really going to change. We have a big wake-up call coming and I think a lot of other states are going to be in the same situation as this progresses. So, all right, we keep touching on this a little bit.
Marc Culver:First of all, I just want to mention I've been listening to a podcast in order just to get my knowledge of what PFAS is and some of the background to it and some of the chemistry and technical aspects of it. I've been listening to a podcast called Forever Chemicals and honestly I don't even know how many episodes they have or when they started recording or anything. I'm on the sixth episode right now. They're really good episodes of very technical technical information and experts that they're talking to. It's.
Marc Culver:It's definitely jaded, it's. I mean, these are the people. It's produced by a group of people that are trying to ban PFAS everywhere for everything, and I'm not saying that's not the right thing to do, but there's definitely a. Put the link to this podcast if you're interested in learning more about kind of the background of this and some of the history and some of the other companies that are dealing with this and some of the companies that are like trying to produce and are producing waterproof and resistant materials without using PFAS. So it's kind of an interesting story of some of the options that are already out there. But let's we keep talking. We've said GAC probably about 20 times now and we haven't said what it stands for. But let's talk about these treatment options and GAC probably being the most reasonable treatment option. But what is GAC and why is it probably the best option right now. Okay.
Steve Nelson:GAC stands for granular activated carbon, and you know there's different materials that it can be made of, but it happens Cause you can think of them like simply, maybe like an asteroid If you remember the game asteroids. It's like a rock but it's got a bunch of caves in it. Or maybe for our public works professionals out there, a parking garage is a nice also way to think of it. So you see the piece of GAC, you know a small little pile of that in your palm of your hand might have the area of a football field. So it provides these absorption sites or parking sites. And then, once it's absorbed, if you think that you've got a nine-foot tall bed, deep bed, in a 10-foot diameter vessel, it's called the mass transfer zone. It's called the mass transfer zone as those parking think of each one as a little parking garage.
Steve Nelson:As you work up, you know your first foot of a parking garage is all used up.
Steve Nelson:The traffic goes down the next foot all the way to the bottom and as you get to the bottom you start seeing a breakthrough and that's called the mass transfer zone.
Steve Nelson:And so that's what we're talking, some of the replacement timing that we try and model up front with what's called the rapid small-scale column test, and because we have Oakdale, which we've been working with, and then St Paul Park, which has now been in place like five years, and we have software by Michigan Tech and some of the vendors and PhD experts we work with, we can predict how long that's going to last, because again, that's going to be the big cost for disposal.
Steve Nelson:But what makes it the best is because then you have that lead vessel so you're going to measure there before it starts and then, even if you miss it by a day, for when your department of health is coming out and sampling, you're still for sure not going to go through your leg vessel. So you have a 10 foot diameter vessel in front and then it goes through. A second kind of pop can just kind of a wide spot in the pipe with this Looks like the media that's in maybe a fish tank, you know little filter you have in a fish tank and the reason it was settled on in the settlement is you're not kicking the can down the road.
Steve Nelson:Then you come, you have a truck, semi truck, with a blower on it. They blow out the old stuff, take it away. They come in with another truck and blow in the new stuff into the what was the lead vessel. Then you switch directions, so the what was the leg vessel now becomes the lead vessel and you're starting with the parking garages at the top of the leg vessel and you go the other way. Okay, so that you know the big thing there is. Trying to predict how long that's going to take is, um is a good way. Basically, in our 30-year life cycles we're trying to predict the cost per million gallons for gac replacement.
Steve Nelson:Then you multiply that by how many million gallons per year you have for each treatment plant and the type of distribution of PFAS. You have been going in there so we've been pretty accurate. I wouldn't call it machine learning, but one of our guys was a machine learning master's mechanical engineer from Purdue and he's involved with that and these estimates work great until Murphy's Law happens. So with some of the original installations when 3M was flipping the bill, they did run into things where, whoops, something happened, where accidentally you're going to get head loss, because if anything's going on top of that media and you can't push anything more through there, it doesn't matter if you've gotten your full value out of all your parking garages, if you will. So there's a lot of practical things. So we really like to involve the operators and be appreciative of all they contribute.
Steve Nelson:And when you're starting up your filter kind of a place for everything and everything in its place you want to make sure you have. If you do have to backwash this, you want to make sure that you backwash it really well during startup. You backwash it really well during startup so that if you do get a whoops, then when you backwash it you're going to have all your small parking garages, kind of like your baseballs up on top to your you know volleyballs to your basketballs, because that's what that's the order the distribution of the size particles will be. If you have to backwash, okay, because otherwise we have seen communities and 3m did cover it where that happened accidentally and they had to backwash and then they were getting breakthrough because their basketballs and baseballs and volleyballs were all mixed up. But yeah, yeah.
Marc Culver:So when, when you said, like you know, once the parking ramp is full, then they come in, they pump out the full stuff and they put in new stuff, right. So I got two questions in my mind about that One where does the new stuff and they they put in new stuff, right? So I got two questions in my mind about that one where does the new stuff come from? How's that manufactured and what is? You know the cost of that and, and I think you, in our conversations we, we kind of talked about how this is now going to be become a rare resource that we're all going to be, competing for in the future.
Marc Culver:But secondly, what do you do with the old stuff? What? What happens with the old stuff?
Steve Nelson:The old stuff. So if they reactivate it which they most likely would, because they want to completely destroy it it can be used for wastewater. It can't be used for potable water anymore.
Steve Nelson:They can't remember the temperature, but very, very high temperature. It's DeKalgan or Norwich or one of them is doing testing to prove. I don testing to prove. I don't know if that the results are all, but they basically are completely confident they can break every carbon fluoride bond. So there is no short chain, long chain, no pfos left.
Steve Nelson:The the new stuff is normally a coal-based um, re-agglomerated they kind of because of different um areas you'd mine it from. Every coal is a little different. So they they pulverize it and then they re-agglomerate. It can think of it like making particle board. So you're still getting good strength but you're getting more consistency, um, and that's uh, the virgin carbon, so it's not been reactivated that you're using from that manufacturing process.
Steve Nelson:So every vessel has a 10 foot is kind of the standard has about um. You know, you know the volume in there. I think it's like 550 cubic yards and then it's $2 cubic feet, uh, 20, um, it's about $2 and 75 cents per pound and 20,000 pounds. So it comes out with about it's about a $60,000 whoops per vessel. Wow, so if it happens to your leading a leg then it's a $120,000 whoops. But that's what you're saying. For it's all based on the projected time of replacement. But you really want to involve your operators and be monitoring some things so you know if there's something that happened, like you're getting all of a sudden pressure valleys going up. So you make sure you don't continue doing that and good pre-treatment um ahead of it as well.
Marc Culver:I don't continue doing that. And good pre-treatment um, ahead of it as well. I don't know if I've. Yeah, that's good, that's good. Um, well, I think we're doing really well here. Um, so, and I I I kind of laid out the the doomsday scenario of, you know, every community in the world is going to have to treat this um, and it's probably not that bad. But you guys are more seasoned experts on this. What is your, ryan? What do you think, given your experience, what you've seen, and maybe even just looking at some of the maps that you know, we had that seminar at, or session at, our city engineers conference last week and the department of health was there and he had that map showing you know the testing and some of them, you know the highlighted ones of the ones that were tested over the limit. You know, looking at those maps and things like that, what do you think? I mean, what does this look like in 10 years?
Ryan Stempski:Well, like we've talked about earlier, we're kind of in that testing, collecting data phase and Department of Health has done a good job right now of saying, no, this is a problem and you need to take it seriously. To the smaller communities and the communities just facing this for the first time have been notified that their QRAs another acronym we defined earlier that their QRAs are over one of those thresholds and they need to start implementing regular testing and they need to get their consumer confidence reports updated and they need to plan for mitigation in the future. So we already know we've got the East Metro, we've got Bemidji, we've got the 20 communities that are listed on Department of Health's radar screen, but a lot of private. Well, testing continues all over the Metro and beyond in the state of Minnesota and I think we're looking at that four parts per trillion mark.
Ryan Stempski:I guess my concern is what is the health guidance going to look like? So the big answer is waiting on what our department, Minnesota Department of Health, is going to do with their epidemiology, their results, their findings to protect Minnesota's most vulnerable populations, Right? So I think if, if they lower that to essentially zero is what we're at and they continue testing in retesting areas. Like you said, these plumes, they, they, they move, they don't break down. In Hastings, for example, it's been at least about 15 years of very consistent levels and every well.
Marc Culver:So not not only that they're there, but they're there and present in those certain environments at the same, like that plume is moving through and you're at the bat like a cloud. Right, eventually the sun comes out, right, let's just stay in there, like, like steve mentioned a little bit just the complex, uh nature of these.
Ryan Stempski:They're, they're. Some of them are water soluble. Um, they, they stick to the bedrock and the aquifers. They don't move, they're there. So, yeah, it isn't like a fate and transport that typically will take that chemical out of the community. If you just wait 100 years or 50 years, you know that's some of the reality of this chemical. So it'll be interesting, with the testing and the continued study and the continued lower values that are being talked about in the regulation field, what it will look like in 10 years. But I think, whether it's consumer products or drinking water, just about the lives of everybody in these PFAS areas in the state of Minnesota, we can say for sure is going to be impacted one way or another.
Marc Culver:Yeah, which is scary, which is really scary, particularly from a cost perspective. So did you have something you want to add to that?
Steve Nelson:I guess we didn't mention. You know a couple of the others. Ion exchange is looked at, you know as well. One of the things with that is it's not.
Marc Culver:You're talking about different treatment options. Yeah, different treatment.
Steve Nelson:So it's a resin those have seemed to be more susceptible to if you don't get good pre-treatment. So it's been demonstrated in some of the testing in Minnesota that it leads to that higher head loss right away. You should start to get limited by just how much you can push through. And then if you do like, like at your home softener, where you're exchanging the salt, the chlorides are coming off for the calcium then you'd have all that PFAS going down the drain. So where are you going to regenerate and what are you going to do with it? And if you incinerate it then you've kind of got a glob with PFAS in it. And we're already seeing on the wastewater side that some landfills aren't accepting any waste that has PFAS in it because then they'd have it concentrated in their leachate. So you want to think about that liability down the road. Right now Water producers are going to be regenerated.
Marc Culver:Yeah. So, it's another substance that we're just going to have to, you know, launch into the sun someday, you know, to get rid of it.
Steve Nelson:And you just think about the volume. If we're coming up to, you know, April 2029 and also everyone's ordering this GAC at the same time, we can see what happens when there's supply chain issue and kind of economics. I know we're not great at economics, being engineers, but I think it's a supply and demand thing Right, and it's also a risk thing too. So that's some of the things to factor into the solution you pick, but also the timing, kind of getting to the table while the getting's good for your funding.
Marc Culver:So I do think we'll probably do a follow-up episode on maybe diving into GAC a little bit more, maybe give a little bit more technical background and that into it, but also talk a little bit more about some of these alternate uh technologies and some of the things that are on the horizon and you kind of teased this a little bit earlier in the in the episode when you're talking about the foam but but talk about some of the the other techniques for treating this that are coming up and and does can AI play a role in this?
Steve Nelson:Well, I definitely think AI can, but you know a lot of it is because there's so many different ones. I do think, like even with the lead and copper rule for optimal corrosion control treatment you found, no matter how many PhDs you had looking at it, there's something about just an analogous system, so that's fortunate. Here in Minnesota We've got similar kind of distributions, kind of fingerprints of the distribution of PFAS, and we're seeing that the rapid scale testing and kind of the ongoing monitoring testing is pretty good. As far as being predictive of your costs and your replacement times. The foam fractionation is interesting. I think it's promising, but it's relatively new, so it goes back to that.
Steve Nelson:The carbon-fluorine bond is not the challenge. It's kind of like if you were going to wrestle a mosquito. Can you beat them? Yes, you can smash a mosquito, but it's more like we have three mosquitoes in the US Bank Stadium and you've got to get them in because the water's flowing by. You've got to get them and because the water's flown by you got to get them and take care of them within, you know, 20 minutes.
Steve Nelson:Well, that's a challenge. So the foam fractionation was kind of fumbled upon almost some like a lot of great inventions. Some well drillers were using some surfacant to redevelop a well, and they were, you know. So it's foam coming up out of the well and they're backing that up and then they're testing you know the well water. Afterwards I go there's no more pfos here. What happened to the pfos? They're thinking well, let's check the foam that we knocked down when we you know shop backed it up and sure enough, the pfos likes being in a foam.
Steve Nelson:So one head's attached in the foam film and that's where the idea of foam fractionation. So basically they're getting better and better at making very hard if you will micro bubbles that the PFAS then wants to attach to, and then you're knocking those down and you do that repeatedly. So that's called foam fractionation. And then maybe after months of concentration, you get a thimble full of this really concentrated PFAS. And then, like the equivalent of you swatting is just a treatment that's been around for ages is uv, ultraviolet. You just are basically flowing it through and dapping it with uv and then you break that bond that is being used. The problem right now it's it's very small. It'd be like a a rail car size treatment unit and so it's being used more for landfill leachate waste where you got very concentrated.
Steve Nelson:Again you're starting with the mosquitoes already really concentrated, that we can talk more about that and how that, might you know, develop in the future to be applicable, because that would be ideal to destroy it on site and then you know it's gone right, you don't have to worry about transporting it and burning it, and storing it and all that, keeping it from getting in the air as we incinerate it all yeah, cool.
Marc Culver:Anything else you want to add, ryan?
Ryan Stempski:well, I think it's just again. Uh, steve talked through a lot of great treatment technologies. Uh, I think getting some of your own water chemistry testing and understand what you have and in your water um might help determine some of that too. There's some pre-treatment devices. As you could learn from you know, granularly activated carbon. It's so expensive and it's so critical that you maximize the life of that material for your O&M costs, and so I think what we're really working hard on is understanding the chemistry and then putting in the right pre-treatment devices.
Ryan Stempski:Even iron and manganese can cause an issue. So, you know, even if you have levels that are above the department health threshold, you still may want to do that to protect the life of your granular activated carbon treatment. So, thinking about things like that, thinking about, you know, filters, pretreatment filters that if you have some sandy or dirty or water right you know, can we pull out some of those materials in advance just to maximize. Steve did a good job of just talking about how critical that is in the treatment, so that's been something that's been very useful and helpful as we look at designing the right plant for the right community. Cool, thank you.
Marc Culver:Any last, words look at designing the right plant for the right community. Cool, thank you. Any last words You'll have another chance. All right, we'll give you another hour in the future sometime to talk more, because you're leading up to this episode, I want to say something cool.
Steve Nelson:Yeah, forever ends today.
Marc Culver:That might be trademark, we might be. It might be a trouble. That might be trademark, we might be it might be a trouble.
Marc Culver:You know I've never well not make it sound like I've been doing this for years. You know I've I've done over 30 episodes now and I'll say that I haven't had as many conversations about an episode as I have about this one leading up to recording it. Steve is very passionate about this and he was really worried about what are we going to cover and how are we going to cover it, which I love that. I love the passion and I love his like just the sense of. I want to make sure we get this right, you know, but we've had hours of conversation about this and you are a wealth of information and and I appreciate your time here today and we will we will give you some more time to to talk more about this. So, so awesome, and same to you, ryan. Thank you very much for sharing your experience. I know you're going to be working on this for for a long time, so we'll we'll check in with you again and see how things are going in Hastings. So great, thank you. Thank you, thanks, mark.
Marc Culver:Yep, and before we go, we're on our third season of the podcast here. We'd love to grow our audience and so please help us spread the word by liking, reposting and or commenting on LinkedIn. That's kind of our primary social media outlet, but wherever you see us like it, send us a comment that this is the best podcast you've ever heard, even if it isn't, and let us know what you think of this episode and the podcast and what we really love, and we need episode ideas. So if you're passionate about something and you want to talk about it, reach out to me, let me know. I would love to have you on and we'll nerd out about what you're passionate about in public works. So thanks, everybody, and we'll see you next time. Nerds out.
