The U.S. Environmental Protection Agency recently announced that it has reached an agreement with the Wisconsin Builders Association, the National Association of Home Builders and others to settle litigation challenging revised standards regulating construction stormwater discharges, including a regulation establishing numerical turbidity limits.  The standards were initially adopted in 2009 and then included in the Agency’s final construction stormwater permit in 2012.

The Settlement Agreement, which was filed in December, addressed a number of issues raised in the litigation. A part of the Agreement requires EPA to publish a notice of proposed rulemaking by April 15, accept public comments, and then proceed with the goal of completing final action on the proposed rule by February 28, 2014.

With respect to the turbidity issue, EPA agreed to withdraw the numeric limitation contained in the challenged rule and the permit.  EPA appears to have essentially accepted the plaintiffs’ position that such limits are very difficult to establish because the science surrounding sedimentation is not sufficiently precise to allow creation of a single effective standard.  In a press release about the settlement issued by the National Association of Home Builders,  the organization noted its belief that establishing a single turbidity numeric limit that “would work across all geographic areas and soil types would not be possible.”

Notwithstanding the settlement and the expected rulemaking, the matter may not yet be resolved.  The coming round of rulemaking is likely to generate considerable comment and opposition from environmental groups who have long advocated establishment and implementation of numeric turbidity limits in place of the historic use of narrative criteria.