Owners, contractors and designers should be aware of new requirements for National Pollutant Discharge Elimination System (NPDES) permits for stormwater discharges associated with construction activity. The Environmental Protection Agency (EPA) issued final regulations establishing effluent limitations guidelines and new source performance standards for stormwater discharges from construction sites.

Although the final regulations were effective February 1st, EPA expects states like Oregon that have NPDES permitting authority to incorporate the new guidelines and standards into NPDES construction general permits as they are reissued. For construction activities on Indian reservations and other jurisdictions where EPA retains NPDES permitting authority, EPA will incorporate the new guidelines and standards into its NPDES construction general permit when it’s reissued in 2011 (EPA modified its 2008 NPDES construction general permit to extend the expiration date to June 30, 2011). Individual NPDES permits issued on or after February 1st are immediately subject to the new rule.

The new rule imposes non-numeric standards that apply to all construction sites disturbing one acre or more. The new rule also includes numeric limits for turbidity that will apply to construction disturbing 20 acres or more starting August 2, 2011 and construction disturbing 10 acres or more no later than February 2, 2014. (Note that the December 1, 2009 Federal Register notice incorrectly states that the August 2, 2011 compliance date is August 2, 2010.)