Minnesota River quality going the right direction

St. Paul — Efforts to improve one of the state’s most abused rivers appear to be working, at least in one section of the river, and according to one measuring stick.

The Minnesota Pollution Control Agency announced this week that testing along a 20-mile stretch of the Minnesota River in the southern metro area showed “significant improvements in pollution levels in the river,” according to a PCA press release.

The testing occurred along the river from Shakopee to the Minnesota’s confluence with the Mississippi River, said Glenn Skuta, PCA water monitoring manager, or roughly from Valleyfair to Ft. Snelling.

Conditions, though far from perfect – temperature and precipitation-wise this summer and fall – were ideal for researchers’ purposes, Skuta said. The river water was warm, and flows were low – meaning oxygen levels could be at their lowest, too, “which has been a problem under similar conditions in the past,” regarding oxygen levels, the press release states.

“Right now, the river is flowing at about 600 cubic feet per second,” Skuta said. “Normally at this time of year it’s about double that.”

What officials found during three weeks of testing was welcome, if not surprising.

“The results pleased MPCA scientists because (they) showed that dissolved oxygen levels are good, and supportive of aquatic life, even during stressful environmental conditions, such as low flow and high temperatures,” the PCA press release said.

Added Skuta: “There were no violations of the dissolved oxygen water-quality standard.”

Actions to improve the Minnesota’s water quality have been occurring for decades. In the early 1990s, a well-publicized goal for the river was to make it fishable and swimmable, according to the PCA’s website. The agency is required by the federal Clean Water Act “to adopt water-quality standards to protect the nation’s waters,” and for each pollutant that causes a water body to fail state water-quality standards, the CWA requires states to conduct a “total maximum daily load” study.

For the Minnesota River, a wide variety of pollutants were identified, the PCA says, which affected dissolved oxygen levels and clarity, raised levels of harmful bacteria, and more.

The pollution problem, Skuta said, was the result, primarily, of inadequate wastewater treatment systems.

But, he said in the agency press release, “During the past several years, wastewater treatment plants along the affected stretch of the river implemented several phosphorus-reduction strategies that are working, based on the good dissolved oxygen levels we found in this survey.”

Those changes largely came at the direction of the PCA, and in many cases were moved along financially by state grants and loans, Skuta said.

That 2004 plan and phosphorus-reduction permit included a 10-year schedule during which goals should be reached. Said Skuta: “The wastewater treatment plants covered by the permit collectively achieved the 2015 goal well in advance of the deadline.”

Skuta said that while the DNR, not the PCA, monitors fish and other aquatic species in the river, this week’s news is good for anglers, and that DNR Fisheries workers have found a high number of fish species in other stretches of the river.

Monitoring of the metro stretch of the Minnesota is far from complete. In fact, Skuta said should flows continue to drop, further testing could be done next year to check dissolved oxygen levels during even lower water.

And in the metro as well as along other parts of the river, officials will continue to enforce rules and encourage good stewardship. Along rural stretches of the river, sediment from ag practices is a concern. Land retirement (usually via government conservation programs), voluntary buffers, and erosion-resistant tillage practices must compete with high crop prices, he said. Urban runoff is another contributor of phosphorus to the river, he added.

“There’s still work to be done (regarding) treatment plants, as well as those who work the land (along the Minnesota),” Skuta said.

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