Court Rules EPA Cannot Set TMDL For Stormwater

Posted on April 30, 2013 by Ridgway Hall

On January 3, 2013, the District Court for the Eastern District of Virginia ruled that EPA lacks the statutory authority to set a Clean Water Act (“CWA”) total maximum daily load (“TMDL”) for “stormwater flow rates” as a surrogate for sediment deposition. Virginia Dep’t of Transportation et al v EPA et al.  EPA has decided not to appeal.  The case has received national attention because of its implications for other TMDLs that use surrogates. This article will discuss the decision and its significance for the TMDL and water quality regulatory regime.

The relevant statutory framework is CWA Section 303, under which each state establishes water quality standards for waters within its boundaries.  These consist of a designated use (trout fishing, contact recreation, etc.) and numerical or narrative “water quality criteria” necessary to support that use.  For “impaired waters” where the criteria are not being met, the state must set a TMDL (think “pollution budget”) for each pollutant for which the criteria are exceeded, and implement a “planning process” leading to achievement.  Where the state fails to act, or sets a TMDL which EPA regards as insufficient, CWA Section 303(d)(2) directs EPA to set the TMDL.

Accotink Creek is a 25 mile tributary to the Potomac River in Virginia, in which the benthic organisms were impaired, primarily because of sediment deposited by stormwater running off impervious urban and suburban areas.  In April 2011, after Virginia failed to set a TMDL, EPA set one which limited the flow rate of stormwater into Accotink Creek to 681.8 cu ft/ acre-day.  The court said that the parties agreed that “sediment is a pollutant, and that stormwater is not” (Slip op. 3). While EPA’s brief contains a fallback argument that stormwater can be viewed as a “pollutant”, it did not dispute that stormwater flow was being used as a surrogate for sediment.  Thus the question addressed by the court was whether EPA has the statutory authority to set a TMDL for a “surrogate” which is not itself a “pollutant”. 

EPA has used surrogates in a number of circumstances where, in its view, the surrogate would provide appropriate reduction of pollutants, and would be either easier to measure or provide other benefits (such as, in this case, reduction of stream bank scouring caused by heavy stormwater discharges), or both. The court rejected EPA’s argument that since the CWA does not expressly address the use of surrogates, EPA’s use of them should be upheld as reasonable “gap-filling”, consistent with the broad remedial objectives of the CWA, and entitled to substantial Chevron step 2 deference. The court held instead that because the CWA instructed EPA to set TMDLs for “pollutants”, not “surrogates”, the statute was clear.  The court distinguished EPA’s use of surrogates in this case from other instances  in which surrogates have been used under other CWA provisions (notably Sections 301, 304 and 402) where EPA appears to have greater latitude.

EPA and states have used stormwater surrogates in TMDLs in Connecticut, Missouri and North Carolina. They have also used other types of surrogates, such as impervious surface area limits and secchi disc readings.  Some of those have been challenged, and this decision will no doubt provide ammunition for those who oppose their use.  Nationally, however, this amounts to a very small percentage of the TMDLs that are in place, even if one focuses only on sediment (for which, the court noted, EPA has issued approximately 3700 TMDLs).

In addition, this ruling will have no effect whatever on EPA’s permitting of  industrial and municipal stormwater  discharges, including municipal separate storm sewer systems (“MS4s”), or its ongoing development of stormwater regulations, because these activities are expressly authorized under CWA Section 402(p).  This is especially important, because EPA and many states now recognize stormwater as a major source of contamination and water quality impairment.  For a thoughtful article on this subject and emerging approaches, see Dave Owen, Urbanization, Water Quality, and the Regulated Landscape82 U. of Colo. L. Rev.  431 (April 2011).