Scientists have found a significant presence of organic waste compounds in three Michigan rivers.
The Detroit Free Press reports that the Rouge and Clinton rivers in southeastern Michigan and the St. Joseph River in southwestern Michigan have pollutants from car exhaust, smokestacks, herbicides and detergents.
The U.S. Geological Survey sampled water throughout the Great Lakes region from 2010 through 2013. The Free Press says some organic waste compounds were 10 times higher than water-quality benchmarks.
Government hydrologist Austin Baldwin says the Rouge and Clinton rivers were "among the worst sites ... almost across the board." He says the compounds can cause changes in fish.
The report found water-quality standards were exceeded in 35 percent of hundreds of samples taken from 57 tributaries in the Great Lakes basin.
