What Is the Burden In Proving a Violation of a Stormwater Permit? If It Walks Like a Stormwater Discharge …

Those of us who do NPDES work know that enforcement, including citizen enforcement, against industrial point sources can often be all to straightforward.  The plaintiff marches into court with a pile of the defendant’s discharge monitoring reports and the liability phase may be over quickly.  Stormwater cases are different, as last week’s 9th Circuit decision in NRDC v. County of Los Angeles demonstrates.

The case had a number of twists and turns, including the seemingly de rigueur reversal of an earlier 9th Circuit decision by the Supreme Court.  As we noted at the time, the Supreme Court decision was limited to the unremarkable proposition that a discharge from a culverted stretch of a water body to a non-culverted part cannot constitute a discharge of pollutants under the CWA.

On remand, the 9th Circuit was presented with a nice legal issue regarding the burden of proof.  The County permit provided, as most such permits do, that the County could not discharge pollutants that would cause or contribute to a violation of water quality standards in the receiving body.  Unlike an industrial point source, it is not feasible for an municipal separate storm sewer system, or MS4, to monitor every discharge point.  In the case of the County, it was required to conduct monitoring at seven locations.  The permit provided that the purpose of the monitoring was to:

(1) estimate the mass emissions from the LA MS4; (2) assess trends in the mass emissions over time; and (3) determine if the LA MS4 is contributing to exceedances of Water Quality Standards….

The question addressed by the Court was whether exceedances of water quality standards at the monitoring locations was sufficient to demonstrate that the County’s discharges were causing or contributing to those exceedances.  The Court fund that they were.  In fact, the Court found that the NPDES permit unambiguously provided that monitoring exceedances proved permit violations (notwithstanding that, prior to the Supreme Court decision — which was on a totally separate issue — the Court had rejected this argument!).  The Court concluded that to require that plaintiffs provided further proof that the permittee’s discharges had caused the water quality exceedance would make the monitoring provisions of the permit meaningless.

Frankly, I don’t see it that way, and the court decision seems to ignore what I would have thought were fairly basic ideas about presumptions and the ultimate burden of proof .  It seems reasonable to me that, where the purpose of the monitoring stations is to provide information for determining whether the permittee is in compliance, then exceedances in those locations would establish a presumption that the permittee violated the permit.  It makes sense that, in the first instance, a plaintiff should not have to establish than one specific outfall out of dozens or hundreds discharged a pollutant that caused or contributed to an exceedance at the monitoring station.  However, it should be a rebuttable presumption, rather than, as the Court ruled, an irrebuttable presumption.  Ultimately, if the permittee presents evidence tending to rebut the presumption, the burden of proof would remain on the plaintiff to establish a violation.

The outcome in this case might not change if the rule were that monitoring exceedances merely created a presumption that a violation occurred, rather than establishing liability.  Indeed, in many cases, it may be obvious that the exceedances were caused by the defendant’s discharges.  However, not all exceedances that walk like a permit violation necessary are permit violations.

walks like a duck

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