District Court nixes the use of nonpollutants as surrogates for pollutants in the development of TMDLs

Earlier this year, a federal district court in Virginia issued an opinion that could present challenges for environmental regulators seeking to address impairment of water resources caused by sediment from stream bank and streambed erosion.

In Va. Dep’t of Transp., et al. v. EPA, et al., No. 1:12-CV-775 (E.D. Va.) (Mem. Op. issued Jan. 3, 2013)(O’Grady, J.), the District Court for the Eastern District of Virginia held that EPA — in developing a total maximum daily load (TMDL) to restore a 25-mile long tributary of the Potomac River called Accotink Creek — could not use stormwater flow rate as a surrogate for maximum sediment load.

A TMDL is the total maximum daily load of a pollutant that a waterbody can assimilate and still attain water quality standards. Under the Clean Water Act, states are required to establish TMDLs for impaired waterbodies. States must then decide how to allocate each TMDL among the various sources of pollutants in the watershed. Once allocations to point sources, termed wasteload allocations, are made, the effluent limitations in NPDES permits issued to these point sources must be consistent with their respective wasteload allocations. The aggregate pollutant loading from the point sources, together with loadings from all of the other sources of pollution in the watershed, must not exceed the TMDL.

On April 18, 2011, after Virginia failed to act and pursuant to the terms of a consent decree, EPA established a TMDL for the Accotink Creek. Because EPA believed that sediment was the primary cause of the impairment of the Accotink, EPA designed the TMDL to regulate the amount of sediment in the creek. Instead of establishing a total maximum daily sediment load, however, EPA sought to establish a maximum stormwater flow rate, on the ground that — because sediment load in the Accotink is a function of the amount of stormwater runoff generated within the watershed — a limitation of the flow rate of stormwater into the creek is an appropriate surrogate for sediment load.

Although the sources of surface water impairment caused by sediment are in some instances stormwater discharges containing silt running off construction sites, in other instances the sources of the impairment are stormwater discharges from separate storm sewer systems in impervious urbanized areas, which may themselves contain little or no silt but that collectively contribute to high velocity stream flows that erode stream banks and stream beds. In these instances, a total maximum daily sediment load may be difficult to implement, because silt from these discharges could be reduced or even completely eliminated and the discharges might nevertheless cause sediment impairment if they are collectively contributing to fast flowing streams that scour its banks and beds. One suspects that this is precisely the problem (hereinafter referred to as the “urban flow erosion problem”) that EPA was seeking to address when it proposed stormwater flow rate as a surrogate for sediment in the Accotink Creek TMDL.

The Virginia Department of Transportation (VDOT), however, wasn’t particularly fond of EPA’s proposal and challenged the TMDL under the Administrative Procedure Act (APA). VDOT argued that the Clean Water Act only authorizes the establishment of a TMDL for pollutants and — because stormwater is not a pollutant — EPA cannot establish a TMDL expressed as a maximum stormwater flow rate.

The District Court agreed. Under the first step of the well-known Chevron analysis applied in APA challenges, the Court found that the language of Section 303(d)(1)(C) of the Clean Water Act was unambiguous and that EPA’s authority to establish TMDLs for pollutants could not be extended to establishing TMDLs for nonpollutants as surrogates for pollutants. (The Court provided in dictum that EPA’s attempt to establish TMDLs for nonpollutants also is an impermissible construction of the statute that probably goes beyond “permissible gap-filling” under the second step of Chevron analysis.)

All of which begs the question: If the Va. Dep’t of Transp. opinion stands, will there be any way to address the urban flow erosion problem?

Although the Court noted in its opinion that “EPA has approved 3,700 TMDLs for sediment nationwide” and that “[n]one of them regulated the flow rate of stormwater,” I am not at all convinced that TMDLs that allocate daily sediment loads and are implemented through sediment limits in NPDES permits issued to point sources can adequately address the urban flow erosion problem.

Why not? Because the definition of the term “effluent limitation” restricts its application to “pollutants,” 40 C.F.R. § 122.2, and as the Court and all of the parties in the Va. Dep’t of Transp. case agreed, stormwater is not a pollutant. Unless stormwater can be regulated directly, a discharge of stormwater can meet sediment limits at the point of discharge, yet by its volume or rate create a sediment problem upon entry into the waterbody.

If indeed EPA and the states are foreclosed from addressing the urban flow erosion problem under the authority of the Clean Water Act, states seeking to address this problem will have to look to their own state authority.

And here in Pennsylvania, the Department of Environmental Protection (DEP) may have to search no further than the Pennsylvania Clean Streams Law. Section 402 provides that:

Whenever the department finds that any activity, not otherwise requiring a permit under this act . . . creates a danger of pollution of the waters of the Commonwealth or that regulation of the activity is necessary to avoid such pollution, the department may, by rule or regulation, require that such activity be conducted only pursuant to a permit issued by the department or may otherwise establish conditions under which such activity shall be conducted . . . .

35 P.S. § 691.402(a). Because the term “pollution” is broadly defined in the statute, it appears that DEP may already have the requisite authority to address the urban flow erosion problem. Whether DEP will exercise that authority remains to be seen.