Waterkeeper to EPA: Enforce Montana’s water quality standards

Laura Lundquist

(Missoula Current) For the second time, the Montana Legislature passed a bill to eliminate numerical standards for nitrogen and phosphorus pollution in Montana’s waters, so a water watchdog is once again asking the federal government to enforce the existing standards.

On Wednesday, the Upper Missouri Waterkeeper sent a petition asking the U.S. Environmental Protection Agency to review and reject changes to Montana’s water quality standards mandated by bills passed by the 2025 Legislature and signed by Governor Greg Gianforte.

Three bills - House bills 664, 685 and 736 - eliminated Montana’s numerical water quality standards for nutrients and weakened the state’s nondegradation policy, which upholds the requirements of the U.S. Clean Water Act. With no standards to judge water quality, Montana’s lakes and streams could become degraded to the point where fish, wildlife and human health are affected, said Guy Alsentzer, Upper Missouri Waterkeeper executive director.

“The EPA has a responsibility and legal obligation under the Clean Water Act to ensure Montana agencies protect our waterways and water resources from harmful pollution if the Montana Legislature won’t,” Alsentzer said in a release . “Pollution standards must be science-based and enforceable. From healthy fisheries and drinking water supplies to agriculture and the outdoor economy, billions (of dollars) in economic activity and countless jobs and businesses are on the line.”

Nutrients are compounds that contain nitrogen or phosphorus, which can be harmful in excess amounts and can encourage the growth of various algae called algae blooms. When significant amounts of algae infest streams or lakes, the resulting low concentration of oxygen dissolved in the water can kill fish and other aquatic organisms. Blue-green algae can also release toxins that can poison fish and people.

Ammonia is a major source of nitrogen that can enter lakes and streams directly due to municipal sewage discharges and animal excrement or indirectly through mining operations or fertilizer runoff from agricultural lands. It can lock up oxygen molecules, is highly toxic to aquatic life and is commonly responsible for fish kills.

Around 35% of the state’s river miles are considered “impaired” by nutrients, the Montana Department of Environmental Quality reported in 2020.

Mississippi River tributaries across 31 states contribute varying levels of nutrients to the Gulf of Mexico, especially in the spring as farmers spread fertilizer on their fields. In Florida waters, nutrient-fed algae are choking out native seagrass, causing hundreds of endangered manatees to die of starvation. In the Gulf of Mexico, the deoxygenated “dead zone” — caused by nutrient-laden waters from the Mississippi River — continues to grow. Last summer, it was approximately 6,700 square miles, an area roughly the size of New Jersey.

Obviously, while nutrients can impair local waters, they can also have cumulative effects downstream. So, more than two decades ago, the EPA sought to get ahead of the nutrient problem by encouraging states to exchange more vague narrative water quality standards for numerical standards. Numerical standards are already used for most water pollutants, such as mercury or arsenic. They provide quicker recognition of pollution problems, allowing states to take action if water readings exceed the set concentrations.

In 2015, Montana led the nation whenDEQ adopted numerical standards for nutrient water pollution in some critical Montana streams. The DEQ also set up a system of variances to give discharge permit holders up to 20 years to get into compliance. The EPA accepted DEQ’s standards, which means they’re set unless the EPA approves something different.

That’s what the 2021 Legislature tried to push when it passed Senate Bill 358 requiring DEQ to eliminate the numeric standards and revert to narrative standards. Montana cities and towns opposed the numerical standards because many would have to install expensive new sewage treatment facilities in order to meet the standards and maintain their discharge permits. SB 358 said DEQ should prioritize the regulation of phosphorus instead of nitrogen.

The EPA is supposed to approve any changes to state water quality standards within 60 days. But in 2021, the EPA did little, saying only that it had concerns about some of the narrative standard proposals and had yet to approve the changes.

Following the 2021 Legislature, DEQ created a working group of stakeholders — agriculture and mining industries, municipalities and environmental advocates including the letter-writers — to develop a narrative standard rule that would be acceptable to them and the EPA. For months, the working group struggled, unable to agree on much of anything.

In the meantime, the lack of action on the part of the EPA prompted Alsentzer to declare his intent to sue the agency for failing to uphold its responsibilities and the Clean Water Act. In May 2022, the EPA finally informed DEQ that discharge permits could not be issued based upon narrative standards because the new standards hadn’t been approved. To earn that approval, the new narrative standards would have to be as protective as the numerical standards.

That was too high a bar for the working group to meet. In June 2024, after three years of contentious working group meetings, DEQ hit pause on the effort to create narrative nutrient standards but didn’t give up on it altogether.

““The pause in rule-making will allow DEQ more time to consider the substantive comments received and means that the proposed rule package will not move forward to adoption,” the agency wrote in a June 2024 press release.

Now, with the passage of HB 664, the entire process is primed to begin again. So Alsenzter has reminded the EPA that it has 60 days to respond to the legislation.

“EPA must take action quickly as the state legislation contains unlawful immediate effective dates contrary to express requirements of the (Clean Water) Act. As discussed herein, Montana’s revised water quality standards are unlawful in several respects and there is no rational basis on which EPA can approve these revisions,” Alsentzer wrote.

Under other presidential administrations, the process might have ended the same way: The EPA nullifying the “effective immediately” phrases in the bills and holding a hard line on proposals for narrative standards.

But the Trump administration has already started rolling back EPA protections for clean air and water. It has also cut personnel rolls and budgets to the point that many federal agencies are less able to carry out their mandates. The EPA has lost more than 730 employees since January 2025, and President Donald Trump’s proposed 2026 budget calls for a 35% payroll cut for staff working on science and environmental policy.

EPA administrator Lee Zeldin defended the cuts during a May 22 Senate hearing. So it’s hard to know how he’ll respond to Alsentzer’s letter.

Contact reporter Laura Lundquist at lundquist@missoulacurrent.com.