The Missouri Department of Natural Resources has identified a new batch of lakes and streams that do not meet water quality standards.
The state agency added 60 water bodies to this year’s draft list of impaired waters, including several in the greater St. Louis region. Many of the listed water bodies had high concentrations of bacteria or algae, often linked to runoff from cities, towns and farms.
Under the federal Clean Water Act, states must submit an updated list to the Environmental Protection Agency every two years.
In Missouri, there are 356 water bodies on the 2020 draft impaired waters list statewide. Of these, 100 are lakes and 256 are rivers.
Nearly one-third of waterways had high concentrations of E. coli bacteria, including sections of the River Des Peres and the Missouri River. Other common issues included mercury in fish tissue and high algae concentrations.
Mary Culler, executive director of the nonprofit Stream Teams United, points out that while water quality has improved in some Missouri streams in recent decades, the health of others has declined.
“It has to do with how the land is being used and managed in the watershed,” Culler said, adding that pollutants on land often wash into Missouri waterways.
Nutrients from urban runoff and commercial agriculture seep into waterways, giving fast-growing algae a leg up and resulting in low oxygen concentrations.
Coal-burning power plants also emit mercury vapor, which can pollute rivers and lakes when it rains. About 1 in 8 impaired water bodies in Missouri had fish whose tissues had high mercury concentrations, including August A. Busch Lake in St. Charles County.
The report does include encouraging news, however. This year, the department has proposed removing 33 lakes and streams from the impaired waters list.
Water quality improved to acceptable levels for about two dozen of these water bodies, including a section of the Mississippi River near Ste. Genevieve with previously high E. coli concentrations. Other potential de-listees now have a pollution control plan in place, known as a total maximum daily load, and could be shifted to a new official designation.
Expanding monitoring efforts
The number of impaired rivers and lakes in Missouri has increased steadily over the past decade, but DNR environmental supervisor Robert Voss said that’s because more water bodies are being tested.
“Over time, as we are able to monitor more lakes and streams, it may look like the problem is increasing,” said Voss, who helped produce the impaired waters draft list. “The problem may have already existed, but now that you start looking for it, it looks like you’re observing more of it.”
The DNR gathers water quality data from partner organizations, including county health departments and universities, but isn't able to monitor every lake and stream in the state. That means there are likely more impaired water bodies in Missouri than are listed, Mary Culler said.
“There’s over 115,000 miles of streams in the state,” Culler said. “Not every stream has enough data to be evaluated.”
Still, tracking the health of Missouri’s lakes and rivers — even a subset of them — is critical, Voss said.
“The quality of water is important to all of us,” Voss said. “How can you know if you're making improvements if you don't track and measure what things are good and what things are poor?”
Missouri DNR will host a public hearing on the draft impaired waters list at 9 a.m. Feb. 13 in the Gasconade Camp Conference Room, 1101 Riverside Drive, Jefferson City.
The department will accept written public comments through Feb. 20.
Rivers and lakes in the St. Louis region listed in the 2020 draft impaired waters list:
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