COON RAPIDS, Minn. – Two sheens flowing on the surface of the Mississippi River originated at a dam operated by the Three Rivers Park District in Coon Rapid. A valve malfunctioned on Tuesday and 30 gallons of lubricant spilled, the District confirmed. Although a petroleum product, the lubricant is not harmful to food or drinking water, the District said. The sheens were spotted first on Wednesday morning a couple miles downstream at the State Highway 610 bridge north of the Interstate 94 crossing of the Mississippi.
Three Rivers’ dam. Built in 1913 for hydroelectric power.. In 2005 a major scour hole on the downstream side was repaired. Another scour was identified by underwater sonar scan in 2009, posing questions abut the dam’s longevity and operability.