Three conservation groups are criticizing the Wyoming Department of Environmental Quality for allowing polluting flows to continue at a Fremont County gas- and oilfield and have asked the state agency to reconsider its permit.

DEQ should re-open its review of Aethon Energy’s permit at the Moneta Divide field, modify it and “ramp-up” enforcement of existing violations to meet the agency’s obligations under the Clean Water Act, the groups wrote in a March 17 letter. The Powder River Basin Resource Council, Wyoming Outdoor Council and Natural Resources Defense Council made the request after the DEQ modified the pollution permit for the field, which Aethon and Burlington Resources are expanding from roughly 800 to 4,250 wells, most of them gas wells.

“We remain concerned that DEQ is simply not doing enough to correct longstanding significant water quality violations, resulting in the continuation of unlawful discharges of pollution,” the groups said.

Why it matters

Aethon’s discharges of polluted “produced” water pumped from wells flow into Alkali and Badwater Creeks above Boysen Reservoir. The protected Wind River flows from the reservoir’s Boysen Dam. Thermopolis gets drinking water from the waterway about 23 miles below the dam.

The groups wrote that pollution from the field shows the water failed standard toxicity tests on flathead minnows and water fleas. The groups ask that the agency increase the frequency of those tests.

Elevated chloride concentrations also worry the groups, who say that brine harms freshwater aquatic life and has “likely contributed to severe adverse impact” to Alkali Creek.


Aethon has struggled to find an adequate method of disposing of millions of gallons of tainted water a day and thousands of tons of pollutants a month. DEQ rejected the company’s application to let the pollutants flow into Boysen Reservoir where it would be diluted. In 2020 DEQ issued a permit requiring monitoring and significant reduction of salinity by 2024.

Aethon reported in early 2021 and twice thereafter that discharges exceeded limits set in that 2020 permit. DEQ then made a “major modification” to that permit, removing or increasing some of the limits, ending some periodic sampling and moving some sampling locations. The agency contended sampling results justified the changes.

That modification prompted the groups’ recent appeal. 

Who said what

DEQ should penalize Moneta operators for repeated failures to meet the toxicity test standards, the groups’ letter states. It also should accelerate a plan to reduce the salinity of discharged water by making Aethon re-start the water-cleansing Neptune plant that the company had shut down.

“High concentrations” of Benzene and Toluene found in samples appear to violate DEQ rules and regulations, the letter states. Neither DEQ nor Aethon responded to messages seeking comment by publication deadline.

Angus M. Thuermer Jr. is the natural resources reporter for WyoFile. He is a veteran Wyoming reporter and editor with more than 35 years experience in Wyoming. Contact him at or (307)...

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  1. Evidently life isn’t that sacred in Wyoming we are going to protect the unborn child which is a good thing . But only to give it an environment that’s polluted to live in .

    1. There is a fundamental difference between pro-life and pro-birth. Pro-life folks don’t give a damn after a child is born.

  2. DISAPPOINTMENT: Those of us in Thermopolis were dismayed to learn Aethon is still discharging into Alkali/Badwater Creek thence Boysen. We thought the WOGC ruling to allow injection into the deep Madison fm had been approved and Aethon was disposing of production water into the Madison. Now it appears we have reverted to the same old unresolved situation – only worse since the Neptune reverse osmosis plant is apparently still shot down. Even worse, there are indications that DEQ may still be pursuing a method of circumventing water quality standards and enabling discharge into Boysen. And, Alkali/Badwater Creek bottoms – where sludge has grossly contaminated the aluvium – where Aethon was issued a NOV ( Notice of Violation ) – has not been cleaned up .

    In all fairness, much of the sludge was probably not discharged by Aethon and dates back to the old Frenchy Draw oilfield days of the 1960s and 1970s. Aethons big mistake was buying an oil field with substantial pollution issues – an action which means they inherited the cleanup responsibility. The sludge in the creek bottoms may even be enough to warrant listing as a Super Fund site. At any rate, Aethon will have major problems trying to sell the property for a huge profit since no one wants to buy a polluted property. By now, Aethon management must realize they have to solve the production water discharge problem AND clean up the creek bottom in order to make the property marketable. I once had a house in the Black Hills which had an “unmerchantable” title to due an encroachment issue – I cleared up the matter and latter was able to sell the property – but only after the problem was resolved. I see Aethon having a similar problem with the Moneta Divide field – the problems must be resolved before it can be marketed – dead in the water so to speak.

    Aethon’s other option is injecting into the tight clay wells they currently own; however, these wells are limited in their capacity to receive discharge water and possibly have some expansive clay problems. Not the best injection wells but better than nothing and certainly expensive to maintain. Aethon has until 2024 to reduce the chloride content of the discharge water down to 230 ug/l but that is a tall order at best and might be unattainable without reverse osmosis treatment. But even RO has drawbacks since the reject water has an increased brine content and must be injected whilst the clean water is discharged into the creek. Time is running out and the options are limited and expensive.

    High oil prices are working in Aethon’s favor and might generate enough cash flow which Aethon can utilize to resolve the production water discharge problems. The easiest way out of this mess is for the Moneta Divide field to become very profitable – enough so, that the Neptune plant can be reopened.

    Unfortunately, the whole issue will be reopened and continue to be contentious until the discharge water quality problem and the clean up of the sludge problems are resolved. I personally hope Aethon now realizes these 2 problems have to be satisfactorily resolved for the property to be merchantable and profitable.

  3. Gee, where are you House Dist 55 Rep EMBER OAKLEY? Mega-tons of pollutants are being poured into your backyard, the Wind River drainage. You apparently had time in Cheyenne to raise fines and put people behind bars, yet have turned your back on the sludge being dumped into Boysen. Who do you represent?

    1. She’s to busy waiting for the next Q drop to happen. She ran for office to further herself. She has no interest in representing Fremont County or its people. If you’re lucky, you can run into her at one of the local bars, and you can hear for yourself what she supports. You better have a designated driver though. You’ll want to drink after hearing about the issues she’s “passionate” about.

      1. Agreed but, not sure what’s out there for her to “further herself” does she think the Governor’s office is in reach? LOL. So far, she can’t make a legislative move without first going through Ogden Driskell way over in Devil’s Tower. If Bethany Baldes decides to run again for the HD 55 seat, Oakley won’t be squeaking by with 0.6% vote margin, it’ll be a landslide in favor of Baldes. Run Bethany RUN!!!!! Meanwhile Ember, could you please at least act concerned over the pollutants being discharged in your back yard?

        1. Oakley and Driskill are part of the wacks that feel teaching “both sides” of the holocaust is appropriate. If there was ever voters regret, I hope those who voted for her here in Fremont County are suffering from it.

  4. these companies should be required to TREAT their produced water to drinking water quality (as defined by the US EPA). We’re facing severe drought here in the Western US; and, potable water sources are disappearing. Potable water is NOT free. it’s long overdue that all water users, including municipal wastewater, is treated as non-renewable and therefore must be protected at all costs.

  5. DEQ is nothing more than a rubber stamp for the activities of plunderers. Sort of like what EPA has become as the country became increasingly fascist and worshipful of the oligarchs of kaputalism.

  6. The question to ask is why hasn’t the Wyoming DEQ taken action to stop this pollution. Is personal gain involved or are they just unqualified for this responsibility?

  7. Another great article by Thuermer. This is one more example of all of the harmful and costly effects of the energy industry that they & their politicos ignore when they talk about all of their “benefits” to the State.