In a proposed rule to be published today, April 1, 2013, in the Federal Register, the United States Environmental Protection Agency will withdraw the numeric effluent limits for construction stormwater turbidity that the agency previously had proposed in 2009.  EPA is now proposing a rule that specifies minimum Best Management Practices (BMPs) as effluent limitations for purposes of controlling  pollutants in construction site stormwater runoff.  In general,  the rule concludes that BMP-based effluent limits constitute both a technically feasible and a cost effective way to regulate construction site stormwater pollutants.

This development will not eliminate stormwater monitoring or the construction stormwater numeric action levels set forth in the Construction Stormwater General NPDES Permits that govern construction sites in certain states that have assumed administration and enforcement of the federal Clean Water Act NPDES permitting program, such as California and Washington.  But this development will assure more cost effective regulatory compliance for construction sites in states, such as Texas, that are still subject to stormwater regulation by EPA because those states have not yet been granted delegation of federal Clean Water Act permitting authority.  This development also indicates that EPA has determined that the technical hurdles for controlling and treating pollutants in stormwater and the extremely high costs of stormwater compliance with numeric limits for pollutants like sediment make BMPs, and not numeric limits, the appropriate approach to controlling stormwater pollutants to the "maximum extent practicable" as required by the federal Clean Water Act.   In light of this proposed rule, it appears that EPA will not be proposing to raise the already extremely high bar set by California’s State Water Resources Control Board and Washington’s Department of Ecology when those agencies adopted their statewide Construction Stormwater General NPDES Permits.