Bloomberg Law
Free Newsletter Sign Up
Bloomberg Law
Advanced Search Go
Free Newsletter Sign Up

EPA Scientists Slam Trump’s Waters Rule Rewrite (1)

Dec. 31, 2019, 6:21 PMUpdated: Dec. 31, 2019, 7:25 PM

Several aspects of the Trump administration’s attempt to rewrite federal water pollution rules have “no scientific justification,” according to a group of scientists assembled by the EPA.

This rewrite “decreases protection for our Nation’s waters” and is “in conflict with established science,” the scientists wrote in a draft version of a letter they plan to send to the Environmental Protection Agency.

The draft letter was posted online Dec. 31 and will be finalized at an upcoming meeting of the agency’s scientific advisers scheduled for Jan. 17.

The target of the scientists’ criticisms is the administration’s rewrite of the Waters of the United States rule, or WOTUS (RIN: 2040-AF75). The rule defines which bodies of water are protected by federal anti-pollution regulations and which aren’t.

“EPA always appreciates and respects the work and advice” of the advisory board, agency spokeswoman Corry Schiermeyer said in an email. But federal agencies have an obligation “to act within the authorities granted to them by Congress and the limitations established by the Supreme Court.”

She added that, though the rulemaking may be informed by science, “science cannot dictate where to draw the line between federal and state or tribal waters, as those are legal distinctions established within the overall framework and construct of the Clean Water Act.”

‘A Conflict Exists’

After decades of legal disputes, the Obama administration adopted a broad water body definition in its 2015 WOTUS rule, much to the ire of many industry groups who feared it would cause previously unregulated creeks and streams to fall under federal purview. This fall, the Trump administration formally repealed the Obama rule and is now working toward replacing it with a far narrower definition of federal waters.

This narrowing makes little to no scientific sense, according to a work group within the EPA’s Science Advisory Board, a panel of independent scientists that examine agency decisions. The latest science shows that pollution in streams that may appear small or isolated—or even pollution in groundwater—can flow and cause harm to larger water bodies, the work group wrote in its draft letter.

The proposed rule doesn’t fully incorporate a 2015 EPA “Connectivity” report that showed that how waters are connected depends on function and not just geography, the letter said.

“The proposed rule offers no comparable body of peer reviewed evidence to support such a departure and no scientific justification for abandoning the more expansive view of connectivity of waters accepted by current hydrological science, which has advanced substantially since the CWA [Clean Water Act] was enacted decades ago, as reflected in the Connectivity report,” the letter said.

However, the scientists also acknowledged that the Trump administration crafted its new WOTUS rule with more than science in mind. They said the administration was clear it believes the Clean Water Act and subsequent court rulings prohibit an overly broad definition of protected water bodies and that its goal is to correct what it sees as the legal missteps of its predecessor.

“It is readily apparent that a conflict exists between current, recognized hydrological science versus the [Clean Water Act] and its subsequent case law,” the scientists wrote. “This suggests new legislation is needed.”

The administration is scheduled to finalize its replacement WOTUS rule sometime in January.

(Adds response from EPA in fifth and sixth paragraphs.)

To contact the reporter on this story: David Schultz in Washington at

To contact the editors responsible for this story: Gregory Henderson at; Renee Schoof at