On July 31, the Water Environment Federation (WEF; Alexandria, Va.) submitted comments on the Draft Guidance on Identifying Waters Protected by the Clean Water Act. This guidance was jointly released May 2 by the U.S. Environmental Protection Agency and the U.S. Army Corps of Engineers to clarify which U.S. waterbodies are subject to Clean Water Act regulations.  Recent Supreme Court rulings created confusion on this topic, especially in determining the meaning of a “significant nexus” associated with Justice Kennedy’s opinion.  WEF supports EPA’s intent to provide clarity while understanding that the agency has committed to a formal Rulemaking on this matter.  WEF comments focused on man-made structures such as ditches, swales, reservoirs and ponds to ensure that the existing exemptions on these elements would be protected in the guidance.