MINNEAPOLIS (WCCO) — Even in the grips of winter, the St. Croix River has a peaceful, soothing, pristine look about it.

But a large stretch of the popular and revered waterway from Taylors Falls down to Stillwater is now listed as polluted with high levels of phosphorus.

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Miranda Nichols coordinates the Minnesota Pollution Control Agency’s Impaired Water list, which is a bi-annual inventory of Minnesota’s rivers and lakes that don’t meet Federal Clean Water standards.

“It’s higher than what’s allowable,” Nichols said.

There are currently 3,416 lakes, streams and rivers that don’t meet the standards.

(credit: CBS)

Phosphorus is a runoff pollutant that comes from our fertilized lawns and farm fields.

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“It spurs algae growth and algae growth stresses out fish and bugs. That’s because it depletes the oxygen,” Nichols said.

River advocates point to the river’s tributaries, which are flushing the pollutant into the St. Croix. It is more proof that even a highly-revered and protected waterway is vulnerable to degradation.

Still, there’s optimism as well. According to state testing, evidence shows that the amount of phosphorus in the river continues to decline.

“Data collected by the Met Council over the last 20 years does indicate a trend downward in phosphorus in the watershed. However, it is still not enough to meet our fishable goals,” Nichols said.

But just as the levels built up over time, it will take precious time to rid the river of high phosphorus — returning it to the pristine jewel it deserves to be.

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