Nationwide Numeric Stormwater Limit on Hold While EPA Reworks Data; Lawsuit Still Pending
January 14, 2011

The controversial numeric turbidity limit and associated monitoring requirements for construction site stormwater runoff are officially on hold until EPA reevaluates the data and issues a “correction rule.” 

EPA recently admitted that it miscalculated the stormwater runoff limit published in the December 2009 “Effluent Limitations Guidelines” for the “Construction and Development Industry” (C&D ELG rule) and subsequently announced an administrative stay pending the completion of a new rulemaking.

AGC staff and AGC Environmental Steering Committee members met with EPA’s Office of Water team on Dec. 9 to discuss EPA’s plans to propose a revision to the current numeric limit of 280 nephelometric turbidity units (NTUs) in early 2011 and to take final action by May 30, 2011.  AGC was surprised to learn that EPA is not collecting additional data.  Rather, the Agency will derive its new limit by reviewing and reinterpreting the information currently on file; namely discharge monitoring reports from nine construction sites, spanning just three different states(California, North Carolina and Oregon).  The only other items currently under reconsideration include the feasibility of meeting a numeric effluent limit on cold weather sites, small sites that are part of a common plan of development, and on linear gas and electric utility projects, EPA told AGC.

AGC also continued discussions with EPA on its imminent plans to promulgate a brand new federal Construction General Permit (CGP) permit that incorporates the complex numeric and non-numeric C&D ELG requirements.  Permit revisions are currently in the works and due to go final by the end of June 2011.  EPA believes that one month is sufficient time to take final action on a corrected numeric limit and meet the Agency’s deadline for reissuing its CGP. EPA plans to publish its draft CGP for comment in January, and it is currently undergoing review at the White House Office of Management and Budget.

States authorized to run their own permit programs also are required to incorporate the new C&D ELG requirements into any reissued construction stormwater permits.  According to EPA, states issuing construction stormwater permits prior to the effective date of the corrected numeric limit rulemaking need not incorporate the 280 NTU standard into their permits.  EPA encourages states that were working to promulgate their own numeric limit (i.e., 16 states in 2010 to 2011) to withhold such rulemaking efforts until EPA has acted.

EPA’s action to stay the 280 NTU limit in the C&D ELG does not impact existing stormwater permits for discharges from active construction sites that disturb one acre or more of land.

A fact sheet and the Federal Register notices are available on EPA’s website at

ELG Lawsuit Pending

As reported previously by AGC, the home building industry challenged EPA’s final C&D ELG regulations in the U.S. Court of Appeals for the Seventh Circuit (in Chicago).  AGC also reported that the U.S. Small Business Administration (SBA) and industry had filed administrative petitions with EPA to reconsider the 280 NTU standard, pursuant to the Administrative Procedure Act.

Despite EPA’s admission to the court that the 280 NTU limit is improperly derived, and both industry and EPA’s support for throwing it out, the 7th Circuit refused to vacate the flawed limit.  Instead, the court remanded certain portions of the final rule back to EPA for further reconsideration.  Currently, the EPA lawsuit pending in the 7th Circuit is being held in “abeyance” by the court until after EPA concludes the scheduled May 30, 2011 rulemaking.

For more information, contact Leah Pilconis, senior environmental advisor to AGC, at