Water watchdogs: DEQ’s pollution methods come up short
Laura Lundquist
(Missoula Current) The state of Montana has chosen to update the way it monitors certain water pollutants, but some water watchdogs are calling the changes a step backward.
On Wednesday, prior to the end of a public comment period, two Montana environmental groups urged citizens to ask the Montana Department of Environmental Quality by Oct. 6 to reconsider its proposals for changing its methods for measuring ammonia and dissolved oxygen in state waters.
The Montana Environmental Information Center teamed up with Upper Missouri Waterkeeper to give a presentation on why they found the DEQ proposal to be lacking, and how it could have negative ramifications for Montana’s lakes and streams.
“I don’t believe that they’re required to update this particular guidance at any point in time, because it’s not a regulation per se; it is guidance that the agency uses. But they should be constantly considering and updating these documents,” said MEIC attorney Derf Johnson. “(There’s) a lot of development, a lot of concern over pollution ending up in our waterways. But they can just do a better job.”
JoAnn Burkholder, Director of the Center for Applied Aquatic Ecology at North Carolina State University, explained four main problems that water quality experts would flag in the DEQ’s proposed assessment methods for ammonia and dissolved oxygen.
Ammonia is a major source of nitrogen, one of the two problematic nutrients along with phosphorus that pollute streams, encouraging overgrowth of algae and plants. It can lock up oxygen molecules and is highly toxic to aquatic life, commonly responsible for fish kills.
Salmonids, such as rainbow and westslope cutthroat trout and salmon, are particularly sensitive. Ammonia can enter lakes and streams directly due to municipal sewage discharges and animal excrement or indirectly through fertilizer runoff from agricultural lands.
Dissolved oxygen, the oxygen in water that is available to aquatic life, is normally beneficial, unless the amounts are too low or too high. If the amount is too low, fish can suffocate, and if it’s too high or if the daily fluctuation, called “diel DO fluctuation” is too great, it can stress or kill aquatic life.
Even though the amounts of ammonia and dissolved oxygen in water can obviously take a toll on aquatic life, Burkholder said the DEQ proposal is lax with regard to where, when and how samples are collected and a lot of problems could be missed or underestimated.
“My overall assessment is that these draft methods will make degradation of Montana waters for ammonia and oxygen stress worse for sensitive and valuable aquatic life,” Burkholder said.
First, the proposals provide a vague definition of sampling in an “assessment unit.” For instance, the upper Clark Fork River above Missoula could be considered one assessment unit even though it has several sources that could be adding pollution, particularly ammonia. A DEQ assessor could choose to sample just one site to characterize the entire section as long as the assessor deems the site to be the “most at risk.” But Burkholder pointed out that no preliminary sampling would be conducted to determine which site is most at risk.
“Clearly, multiple sites that contribute major ammonia pollution need to be monitored, not just one site for this entire system,” Burkholder said.
Burkholder also criticized the proposals for allowing the inclusion and collection of inappropriate data, such as including water samples that are a decade old. If they were collected before a pollution source was added, that would cause the average pollution amounts to appear to be less.
The proposal also allows dissolved oxygen samples to be collected between 4 a.m. and 8 a.m., but Burkholder said that would miss the lowest dissolved oxygen readings that occur in the dark before the sky begins to lighten in Montana. For example, in Great Falls around the summer Solstice, nautical twilight - when the sky begins to get light - occurs around 4 a.m. and the sunrise is around 5:30 a.m.
Burkholder said the proposal cuts corners compared to what’s recommended by the best-available science. When sampling sites for ammonia, the science recommends sampling once a week for a year to get a reliable mean value, but the DEQ proposal would calculate a mean based on three samples a year or eight samples in 10 years. It would also not require sampling between Sept. 1 and March 15, but some fish species are going through their early life stages in September so they could be affected.
When sampling for dissolved oxygen, the sampling protocol allows the DEQ to calculate a 30-day mean based on 16 days of sampling and a seven-day mean based on five days of sampling. Plus, the proposed methods assess only minimum dissolved oxygen, not high amounts or large swings that are normally associated with algal blooms.
“Sixteen days of sampling does not represent a 30-day mean,” Burkholder said. “It just seems obvious that, with continuous data measurements, one should sample dissolved oxygen for 30 days to get a 30-day mean.”
The DEQ proposal says that more sampling would be too costly. Burkholder said Montana labs process ammonia samples for $25 per sample or less, which is low compared with other pollutants.
“Besides, salmonids are part of what Montana is famous for. They’re worth about $350 million or more per year to Montana’s economy,” Burkholder said.
Johnson said he was concerned about the proposal’s dependence on modeling as opposed to data collection.
“There’s a lot of room for error (with modeling). The assumptions that go into it can be really problematic and subjective, “Johnson said. “What we want to see is actual data points and a robust data set to determine what the baseline is and what impacts may occur in the future.”
As with all DEQ changes to water standards and methods, the U.S. Environmental Protection Agency must give the state final authorization based upon the requirements of the Clean Water Act. For example, the EPA approved Montana’s numerical standards for nutrients, including nitrogen, in February 2015. After the 2021 Montana Legislature required DEQ to backtrack and rewrite a narrative standard that isn’t as protective, the EPA repeatedly voiced its concern with the change, and DEQ finally abandoned its efforts in June.
Burkholder said the DEQ’s proposed assessment methods also don’t address the role of ammonia as a nutrient. Johnson said he was concerned that the proposal deviates from accepted best practices and could be rejected by the EPA as violating the Clean Water Act.
“In Montana, we have the right to a clean and healthful environment. It’s constitutionally protected,” Johnson said. “The Montana Supreme Court has said this law is not just looking back in time; it’s anticipatory and preventative. And the specific language they used is ‘It doesn’t require dead fish to float on the water’ before we decide whether or not its far-reaching protections should be implemented.”
The DEQ is also proposing assessment measures for selenium but only in Lake Koocanusa and the Kootenai River. Send comments to the Department of Environmental Quality, Water Quality Planning Bureau, P.O. Box 200901, Helena, MT 59620, or electronically to jmadison@mt.gov.
Contact reporter Laura Lundquist at lundquist@missoulacurrent.com.