DEQ’s Big Hole Impairment Decision Lands in Court
Upper Missouri Waterkeeper raises Clean Water Act claims against state regulator
By Amanda Eggert, Montana Free Press
An environmental group is suing the Montana Department of Environmental Quality (DEQ) over its decision not to list the Big Hole River as impaired by nutrient pollution.
Upper Missouri Waterkeeper argued in a brief filed in state district court May 9 that the DEQ’s decision is wrongfully premised on a 2021 bill that was rejected by federal regulators.
In a press release about the lawsuit, Upper Missouri Waterkeeper Executive Director Guy Alsentzer argued that DEQ’s April 14 decision to deny the impairment petition it received the prior month was based on a selective application of Senate Bill 358. The U.S. Environmental Protection Agency rejected SB 358 the year after the Montana Legislature passed it, citing its failure to comply with the Clean Water Act.
In its impairment petition, Upper Missouri Waterkeeper and the Big Hole River Foundation argued that excessive levels of nitrogen and phosphorus, which are often associated with poorly maintained septic systems and fertilizer runoff, have contributed to the recurrent algal blooms that have matted the Big Hole in recent years. Algal blooms can contribute to increased water temperatures and deprive fish and the bugs they eat of the oxygen they need to thrive.
“DEQ’s refusal to apply the laws on the books is a violation of a clear legal duty, and a disservice to one of Montana’s most cherished rivers,” Alsentzer said in the release. “Montanans rely on DEQ to follow best available science and the law, not to bend to political pressure or selectively ignore its own rules.”
DEQ declined to comment on the matter, citing the litigation.
Upper Missouri Waterkeeper is asking state district court judge Michael McMahon to vacate DEQ’s denial of the petition and reconsider an impairment designation for the Big Hole.
The lawsuit describes algal blooms as “evidence that a freshwater ecosystem has reached, and passed, an ecological tipping point” and argues that the recent decline in the Big Hole’s trout population has “coincided with the Big Hole River Foundation’s documentation of chronic seasonal exceedances of numeric nutrient criteria.”
DEQ’s denial of the impairment designation could result in the agency issuing new discharge permits, which would exacerbate the nutrient pollution issue, according to the lawsuit. The plaintiffs also argue that pass-through public funding to support targeted restoration projects is at stake.
In an April 24 email to Montana Free Press, DEQ wrote that an impairment designation is not required to implement water quality improvement projects such as creating riparian buffers, improving forest roads, or creating shaded areas.
Upper Missouri Waterkeeper filed the lawsuit a week after Governor Greg Gianforte signed House Bill 664, a measure that passed the Montana Legislature with bipartisan support. HB 664 mirrors the federally vacated 2021 measure that DEQ cited in its letter denying the impairment petition.
Like its predecessor bill, HB 664 seeks to strike the numeric nutrient standards Montana adopted a decade ago in favor of more subjective narrative standards.
During committee debate on HB 664 on February 26, DEQ Director Sonja Nowakowski argued that “individual, site-by-site” water quality standards are preferable to more broadly applicable numeric standards. Opponents countered that HB 664 is “not defensible” and fails to protect agricultural and recreational industries that are important to the state’s economy.
DEQ is scheduled to appear in state court Friday to defend its denial of the impairment petition.