As expected, on October 14, 2014, (79 FR 61590) the United States Environmental Protection Agency (USEPA) and the Army Corps of Engineers extended the public comment period for the proposed rule “Definition of Waters of the United States under the Clean Water Act” for a period of 30 days until November 14, 2014. The stated purpose of the extension was to allow additional time for public comment on technical support documents including the Science Advisory Board’s September 17, 2014 Draft Report which examined the science underpinning the USEPA’s proposed rule. The extension also results in keeping the comment period open until after mid-term elections.

The Corps and USEPA are expected to mount a vigorous defense of the proposed rule. The Science Advisory Board draft report certainly provides additional support for the agency’s broad assertion of jurisdiction over seemingly isolated wetlands, and most intermittent and ephemeral streams. The draft report states that the “available science provides an adequate scientific basis for key components of the proposed rule.” The Science Advisory Board’s draft report, in fact, recommends further extending jurisdiction to certain ephemeral streams in arid environments and are recognizing the impact of groundwater on the connectivity of non-adjacent wetlands with tributary systems.

The final Science Advisory Board report is expected by the end of October 2014. Taken together with EPA’s September 2013 draft report “Connectivity of Streams and Wetlands to Downstream Waters: A Review and Synthesis of the Scientific Evidence” the EPA is carefully constructing its defenses to the inevitable challenges to the proposed rule.