State approves new metals limits in water

North Carolina's Environmental Management Commission has approved long-overdue water quality standards that stiffen limits on metals, which can be toxic to fish and other aquatic life.

Federal law requires the updates every three years to recognize research on pollutants' effects. North Carolina is four years late, a delay state officials blame on the complexity of the standards and policy changes that made it harder to enact new rules.

The changes won't take effect until the Environmental Protection Agency approves, and EPA has already signaled some concerns.

The standards include a provision called the "biological trump" that allows some concentrations of metals to exceed the limits if there's no evidence aquatic life has been harmed.

EPA says biological studies are of little use in preventing water pollution and don't replace the need to enforce pollutant limits. We'll update when EPA rules.