On December 1, 2009, the U.S. EPA published effluent limitation guidelines and new source performance standards for the construction and development point source category of NPDES permits. See Roetzel's First Quarter 2010 Environmental News (ralaw.com/enviro_news_1Q2010) for more specific information about the new guidelines and standards. In brief summary, this rule establishes requirements to control the discharge of pollutants from construction sites and requires construction site owners and operators to implement a range of erosion and sediment control measures and pollution prevention practices to control pollutants in discharges from construction sites. These requirements were effective on February 1, 2010. In addition, the rule subjects discharges from certain larger construction sites to a numeric turbidity effluent limit of 280 Nephelometric turbidity units ("NTU") beginning in August 2011.
Subsequent to its enactment, the U.S. EPA received petitions for reconsideration of the rule. These petitions identified a potential error in the calculation of the numeric limit for turbidity. The U.S. EPA reviewed its dataset underlying the 280 NTU limit and concluded that it improperly interpreted the data and, as a result, its calculations were no longer adequate to support the 280 NTU numeric limit. The U.S. EPA then issued a direct final rule staying the 280 NTU numeric limit until the calculation is corrected. The U.S. EPA intends to publish a final rule by May 30, 2011. The revised limitation would then be effective by June 29, 2011. Furthermore, the U.S. EPA intends to incorporate the corrected numeric limitation in its Construction General Permit by June 30, 2011. Each state will be required to adopt the final numeric limitation when it adopts its next renewal Construction General Permit.