On Jan. 3, a federal court ruled that the U.S. Environmental Protection Agency (EPA) exceeded its authority in establishing a flow-based total maximum daily load (TMDL) for Accotink Creek in Fairfax, Va. The flow-based TMDL used stormwater runoff as a surrogate for sediment loading in the stream. The court decided the case in favor of the plaintiffs, Fairfax County and the Virginia Department of Transportation, who sued EPA on the basis that stormwater runoff is not, itself, a pollutant. The ruling was based on the view that while EPA can dictate the pollutants attributed to a TMDL, Congress is the body who defines what a pollutant is. See the decision here.
This ruling will likely impact the pending flow-based Wilson with Jordan Creek TMDL and the Pearson Creek TMDL (Springfield, Mo.). It may also impact the status of the 2010 memo released on stormwater TMDLs. This memo, which has been at the Office of Management and Budget since March 2012, suggested the use of flow as a surrogate for other pollutants or impairments.