Small headwater streams, small wetlands, and ephemeral water bodies would get greater protection under a proposed rule unveiled today by the U.S. Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers (Army Corps).  The move, designed to clarify rules under the federal Clean Water Act, has been expected for months and was backed by a report released this past December by EPA’s Science Advisory Board (SAB).  The public now has about 3 months to comment on the rule, which is drawing opposition from agricultural groups  and others. 
“We are clarifying protection for the upstream waters that are absolutely vital to downstream communities,” said EPA Administrator Gina McCarthy in a statement.
The rule will “better protect our aquatic resources, by strengthening the consistency, predictability, and transparency of our jurisdictional determinations,” added Assistant Secretary of the Army (Civil Works) Jo-Ellen Darcy.
The rule attempts to clear up confusion created by Supreme Court decisions in 2001 and 2006 that complicated efforts to regulate development in and around smaller streams and wetlands, particularly those that dry up for part of the year. EPA estimates that about 60% of U.S. stream segments flow seasonally or only after rain. But even such temporary water bodies can have a major impact on the health of downstream waters, EPA’s science board found, and agency officials argue that justifies their inclusion under Clean Water Act protections, which some agency critics have argued apply only to larger, more permanent water bodies.
Environmental groups are praising the move. “EPA took an important step to finally rescue these waters from legal limbo,” said Peter Lehner, executive director of the Natural Resources Defense Council, headquarted in New York City, in a statement.  But he predicted that “[e]ven though these are common-sense protections, the polluters are sure to attack them.”
Critics argue the agencies are overreaching and moving without a full accounting of the science. “In preparing this proposal, the EPA failed to incorporate adequate peer-reviewed science in accordance with the agency’s own statutory obligations,” said Representative Lamar Smith (R-TX), chair of the House of Representatives Committee on Science, Space, and Technology, in a statement. “It’s troubling that the Administration proposed this expansion before its independent science advisors have had the chance to complete its review of the underlying science. The Obama administration continues to sidestep scientific integrity in order to fast track an abusive regulatory agenda.”
The agencies, however, say they’ve fully assessed the science. EPA’s science advisers presented “a review and synthesis of more than 1,000 pieces of scientific literature,” according to their statement. And “the rule will not be finalized until the final version of this scientific assessment is complete.”
The rule is expected to be published soon in the Federal Register. The public will then have 90 days to comment.