The Iowa Department of Natural Resources (DNR) last week released its 2018 list of impaired waters and asked for public comment. The report removed more than two dozen Iowa water segments from the impairments list but added others.

In all, the DNR said that out of the 1,421 segments of streams, rivers or other water bodies it studied in Iowa, 363 segments fully met the Iowa water quality standards, such as swimming or fishing. However, 622 segments didn’t meet...