In a first-of-its-kind decision, a Washington state federal court found the Washington State Department of Transportation liable under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, commonly known as “Superfund”) for storm water runoff from highways.  (United States v. Washington State Dept. of Transportation, W.D. Wash. No. C08-5722, 6/7/2010)

No other court has previously found anyone liable under Superfund for “arranging to dispose” of storm water runoff.  The court found that by designing the drainage system for the highways, the state Department of Transportation was liable for the release of hazardous substances contained in the storm water.  The pollutants were those one would commonly expect in highway runoff and included several metals (cadmium, lead, zinc, nickel) as well as petroleum hydrocarbons and phthalates.

The particular highways at issue drained to two waterways located within the Commencement Bay-Nearshore Tideflats Superfund site on the Puget Sound in Tacoma, Washington.  The result of the court’s determination of Superfund liability now makes the Department of Transportation liable as a potentially responsible party for some or all of the $6.8 million in costs incurred by the government in cleaning up the Superfund site. 

The court did not rule on the state’s argument that its storm water permit (a National Pollutant Discharge Elimination System permit) issued under the authority of the federal Clean Water Act should shield the state from Superfund liability.  A decision on that argument is expected in February 2011.

It remains to be seen what the potential fallout from this case may be.  The federal trial court’s decision on the impact of the storm water permit and any appeal to the 9^th Circuit Court of Appeals (a circuit with jurisdiction over all the states on the West Coast, Hawaii & Alaska) may have broad influence.  Alternatively, the Washington case may be seen as an anomaly with other courts refusing to follow its holding.  However, just the potential for storm water dischargers to be liable under Superfund is significant.