January 11, 2013

Accotink Creek: Innovative TMDLs Down the (Storm) Drain?

Posted on January 11, 2013 by David Van Slyke

On January 3, 2013, an EPA-set TMDL for Accotink Creek (a Fairfax County, Virginia tributary of the Potomac River) was invalidated on the grounds EPA exceeded its statutory authority when it attempted to regulate, via the TMDL, a Clean Water Act pollutant – sediment – by instead regulating a surrogate non-pollutant – stormwater flow.  The opinion granted plaintiff’s motion for judgment on the pleadings; in a separate orderJudge O’Grady vacated the Accotink Creek TMDL and remanded the matter to EPA for further consideration. 

Utilizing the two-step Chevron statutory interpretation analysis, the court found the first of the two criteria had been met:  Congress had addressed in unambiguous language the precise question at issue “… and its answer is that EPA’s authority does not extend to establishing TMDLs for nonpollutants as surrogates for pollutants.”  While directly acknowledging he did not need to reach the second Chevron criterion (whether the agency’s reading of an ambiguous statute is “permissible”), Judge O’Grady nonetheless noted in some detail that “there is substantial reason to believe EPA’s motives go beyond ‘permissible gap-filling.’”

Based upon EPA’s own pleadings, the opinion notes it appears the Agency could have set a TMDL based upon the underlying problem – sediment in the creek – rather than pursuing a surrogate approach.
In recent years, EPA has been pursuing so-called “innovative” TMDLs in an attempt to address stormwater’s contribution to impaired watersheds.  In particular, those TMDLs purport to set load limits based upon various surrogate approaches, including such things as the percentage of impervious cover (“IC”) allowed in the impacted watershed, or (as with Accotink Creek) stormwater flow rates.  While the Accotink Creek TMDL was in EPA Region 3, New England’s Region 1 seems to be in the forefront of this approach and currently has at least three stormwater-source TMDLs in place (including two so-called IC-TMDLs), as well as others in development.  

Given the extensive resources EPA has invested in trying to manage stormwater impacts to impaired streams (see e.g., TMDLs to Stormwater Permits Handbook (Draft Nov 2008)), the Virginia Dept. of Transportation case is clearly a significant setback for the surrogate approach propounded by the Agency.  Whether the United States appeals the decision or retreats and re-evaluates its initiatives in this area is yet to be determined.  Whichever way EPA decides to go, communities dealing with impaired watersheds certainly will need to pay close attention.

Tags: Accotink CreekEPAstormwaterTMDL

Clean Water Act | Emissions | Regulation | TMDLs

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