The interconnection of the natural world has long been part of human wisdom. “All the rivers run into the sea,” notes Ecclesiastes, and they do this even if they are streams that do not flow all year. As long as water flows downhill, pollution in one place can be carried to another.

So it makes sense that the Environmental Protection Agency has long sought to recognize this reality. But Supreme Court rulings in 2001 and 2006 have confused the understanding of which waterways can be subject to EPA rules. On March 25 it issued a proposal to clarify that intermittent streams near bigger ones will be covered.

Although the 1972 Clean Water Act gave the EPA power to regulate pollution in “navigable waters,” Congress defined those broadly as “the waters of the United States, including the territorial seas.” In 1985, the Supreme Court held that a wetland next to a body of navigable water was subject to the EPA.

But in 2006 Associate Justice Antonin Scalia said that the EPA’s power did not extend to saturated fields miles from a bigger body of water. Out of the confusion of this case and another earlier comes the proposal of the new clarifying rule.

Specifically, the proposal states the most seasonal and rain-dependent streams are protected, as are wetlands near rivers and streams. Other types of waters that may have more uncertain connections to downstream water will be evaluated in a case-by-case analysis. In sum, thousands of miles of headwaters, streams and wetlands will return to EPA oversight.

The EPA says it worked with stakeholders who have sought clarity, but the rule is being opposed by more than a dozen GOP senators, led by Pennsylvania’s Pat Toomey, with the support of some farmers. He denounced the EPA’s action as a “terrifying power grab,” saying the “new position seems to be that a puddle from your garden hose will ultimately end up in a navigable waterway.”

No, that is just over-the-top rhetoric speaking. With science on its side, the EPA isn’t interested in regulating puddles or ditches. It is not seeking to shield any new waters not historically covered under the Clean Water Act. It just wants to get on with the job of protecting the environment, which has benefited Americans hugely over the years.

Editorial by the Pittsburgh Post-Gazette