In the town of Lamont, east of Blackwell and near the Kansas border, a Department of Energy atmospheric monitoring station sniffed out a compound never before detected in the air over North America. And it’s toxic.
Called Medium-Chain Chlorinated Paraffins, or MCCPs, they are handy compounds used in high-temperature lubricants, flame retardants, the manufacture of PVC pipes, the production of rubber, paint, and a host of other substances and processes that modern life takes for granted. But now they are showing up in the air.
Recently, the Stockholm Convention on Persistent Organic Pollutants, an international treaty organization to reduce so-called forever chemicals in the environment, concluded that MCCPs are a problem. Linked to liver and kidney damage, and possibly carcinogenic, the organization banned them. At the 12th Conference of the Parties last spring, MCCPs were officially listed in Annex A of the convention on such pollutants. That decision mandates a global ban on their production and use, with some exemptions for critical industrial uses.
They’ve been found in the air over parts of Asia. But now MCCPs have been detected floating in the air around Lamont. A team of scientists from the University of Colorado Boulder found the compound while looking for something else entirely.
“I guess what I would say, in general terms, is that we found something very unexpected that we weren’t looking for and we hadn’t designed the study around,” said Daniel Katz, who at the time was finishing his doctorate. “So when we detected these medium chain chlorinated paraffins, we can tell from our measurements, like we’re absolutely certain that is what we’re seeing, but there are a lot of very interesting questions that we can’t answer.”
Among them, why they were in the air and why in Oklahoma.
“We can definitely say that it’s there, but there’s still a lot of questions that are unanswered from the work that we did,” Katz said.
In addition to Asia, MCCPs are also found in the Great Lakes and parts of Canada, Katz said. But in the entirety of the Western Hemisphere, so far, they hadn’t been found in the air — until now. That raised a question: What, in the middle of the plains of northern Oklahoma and southern Kansas, about as flat and empty as it gets, would cause this toxin to appear? So the scientists looked around at the most likely candidate.
“We saw something that we really weren’t expecting to see, so we tried to come up with the best explanation we could,” Katz said. “We have no direct evidence that’s where it was coming from. There have been measurements in the UK and in China that have shown these compounds do exist in biosolid fertilizers, and so they can be a source,” but added, “We can’t directly show that.”
The study, published in June 2025, appeared briefly in a science publication and disappeared without a trace. Then, last week, Science Daily ran the story.
Hitting the Fan
Biosolids are the treated sludge from human sewage, scraped out of water treatment plants and used for fertilizer. Throughout history, human waste has been well known to act as fertilizer for plants, returning nutrients to the soil and allowing land to better support crop growth. Biosolids were first used in the 1920s and have blossomed into an industry that both removes unwanted sludge from large urban areas and provides nutrients to farms to grow crops.
However, anyone who has changed a diaper or unstopped a toilet knows the smell of human waste. That’s what fields smell like when biosolids are applied in the farming industry, said Rep. Jim Shaw, R-Chandler.
“I’ll be honest with you, from our personal experience with living two and a half miles from some property that someone has been applying biosolids to for years, with a little bit of a south wind pushing that up our way for two and a half miles, it’s unbearable when they put that down,” Shaw said. “And a lot of people complain about the smell and they’re just written off that, ‘It’s not a big deal, it’s just a smell.’ Now I think we’re seeing that there’s some legitimate concerns about what could be in those airborne toxins or that toxins are in the airborne particulates.”
When the story surfaced last week, it landed in the middle of Oklahoma’s legislative punchbowl amid huge debate over banning the use of biosolids. Shaw, who unseated a pro-biosolids incumbent in the 2024 Republican primary, introduced his own bill calling for an immediate ban. It was not heard in committee.
“Our voices, and voices of the people that we represent, have been dismissed as, ‘It’s not that serious,’ or ‘If we figure out the smell, then people won’t care,’” Shaw said. “This new revelation with the airborne toxin brings this to a whole different level. I think, and I would hope, that it would start to get even more serious attention by our colleagues at the Capitol to actually apply the scrutiny that we need to be applying to this issue.”
Shaw is not the only legislator trying to ban biosolids. Sen. Grant Green, R-Wellston, chairs the Senate Energy Committee and has become a leading legislative voice pushing to end the practice of applying biosolids in Oklahoma. Green is a farmer and rancher, and said his views on the subject evolved the longer he looked at it.
“I was really under the thought that I would just mandate that we figure out exactly what’s in it and then adopt some new technology and then move forward,” Green said. “And then as the more I studied it, the more I looked into it, the more I had meetings and conversation, I decided I just wanted to move forward with trying to ban it.”
In 2025, Green passed Senate Bill 3 through the chamber — a phase-out of biosolids land application, with a statewide prohibition taking effect July 1, 2027. The vote was 42 to 4. Then the bill went to the House, where Rep. Kenton Patzkowsky, R-Balko, the chair of the agriculture committee, refused to schedule a hearing.
This year, the House sent back its own bill — HB 3403, authored by Patzkowsky — proposing a five-year pilot study of biosolids through Oklahoma State University. Green amended it in committee with the language from his original ban. The amended version shortens the study to three years, requires a 25% annual reduction in land application during the study, and includes a trigger: if OSU’s research finds that biosolids would be detrimental to the health and safety of Oklahoma, a statewide ban takes effect on December 1, 2029.
“I didn’t interfere with the study,” Green said. “I just clicked a mechanism in it to where we could stop it if the study says that’s what we need to do.”
The amendment passed the Senate Energy Committee 8-2. But Green knows the fight is far from over; the bill goes back to the House, which can accept the amendments, strip them, or kill the bill outright.
“Some of the biggest opposition I have is the people that live in Oklahoma City and Tulsa, the legislators,” Green said. “They take a lot of pressure from their municipalities to vote against this because it will affect them financially.”
The use of biosolids near Oklahoma City and Tulsa leads Green to question whether their use is responsible for the MCCPs showing up in Lamont. He said biosolids are usually applied to land much closer to urban areas, and he is quick to point out that the study did not fully conclude that the source came from such an application.
“To me, when you get in those small rural towns, the possibility of a lot of industrial waste would be very limited compared to Oklahoma City and Tulsa,” Green said. “It’s almost like a cost savings measure for Oklahoma City and Tulsa. Basically, it saves them money and having to deal with these waste products. They get them just outside the cities if they can; I would say most of it spread within 40, 50 miles of Oklahoma City.”
Fertile Debate
The study by Katz and the other scientists at the University of Colorado Boulder suggests strongly, but do not conclude, that biosolids are the cause of the readings at Lamont.
“Based on this observation, we hypothesize that we are seeing MCCPs from several sources surrounding the SGP site,” the study states. “We speculate that one possibility is that MCCPs are present in wastewater and are introduced to agricultural soils via sewage sludges used as biosolid fertilizers and/or wastewater irrigation. (Studies) showed that nearly 70% of MCCP mass loading remained in sewage sludge following wastewater treatment, and MCCPs have been reported in sewage sludges in China, Australia, and the United Kingdom.”
Rebecca Overacre, the Biosolids Program Manager at East Bay Municipal Utility District in Oakland, California, said she saw the study and contacted Katz to suggest they might be jumping to conclusions that biosolids are the source for Oklahoma’s MCCPs.
“I wrote him in the summertime to say, ‘Um, I’m happy for your science and your research, but I don’t understand this one little bit that implicates biosolids,’” she said.
Overacre, who manages the use of biosolids for one of the largest wastewater agencies on the West Coast, said she is happy to laud biosolids use in agriculture and feels confident that biosolids are not the source of the MCCPs.
“I manage the beneficial use of biosolids for my agency, and I come at this from an agriculture background, and I’m fully enamored with the benefits of biosolids. And so we would definitely like to defend their use,” she said.
Overacre said that concluding that the MCCPs came from spreading biosolids is unsupported by any evidence so far, including the Lamont study.
“I have no idea what the cause of those would be, where the sources of that material is,” Overacre said. “All I know is that the article suggested that it might be from the spreading of sewage sludge. And all I know is that that doesn’t make any sense.”
Overacre said she searched her agency’s testing data for all analytes containing any chlorine-based compounds.
“I’m seeing non-detect,” she said.
In Oklahoma, much of the opposition to biosolids stems from studies showing they contain various industrial compounds, including polyfluoroalkyl substances. Overacre said she believes the biosolids industry is being unfairly singled out for a PFAS problem that extends far beyond sewage.
“I personally think that the oil and gas industry has been seeding some false information and pointing the lens at biosolids, because there’s not the same attention on the fracking and the spreading of fracking water,” she said.
As for the source of Oklahoma’s MCCPs, Overacre has different suspicions.
“Obviously, these are compounds from an industrial process, and it’s possible some industries are dumping them into the sewage system,” she said. “Then it could possibly enter the fields that way. But that’s really all I can think of.”
Passing the Smell Test
Saundra Traywick has been fighting this fight longer than most of the legislators now taking it up. A donkey dairy farmer in Luther, Traywick was instrumental in getting the town to ban biosolids within its city limits in 2020. She has spent years pushing state lawmakers to act, only to see her efforts stall.
“I was not surprised at all,” Traywick said of the Lamont findings. “I was only surprised that they actually did the research here in Oklahoma and found it, because what I’ve seen is that we are turning a blind eye to this and we do not want to research it and let people actually know what’s happening.”
Traywick said cities are promoting the use of biosolids to offset the cost of more expensive methods of disposing of the waste, and are pressuring the legislature to maintain the system. She said Sen. Dave Rader, R-Tulsa, introduced legislation that would have exempted cities and wastewater treatment plants from liability for PFAS contamination caused by biosolids.
“They know this is a problem, or they wouldn’t be trying to pass legislation exempting themselves from liability,” Traywick said.
Neither officials from the town of Lamont, nor members of Oklahoma’s Municipal League returned calls seeking comment in time for publication.
This article first appeared on Oklahoma Watch and is republished here under a Creative Commons Attribution-NoDerivatives 4.0 International License.