NW Natural agrees to pay US$32,750 penalty to settle GASCO cleanup violations

Environmental Issues - November 20, 2006

NW Natural has agreed to pay a US$32,750 penalty resulting from NW Natural’s failure to notify US Environmental Protecttion Agency (EPA) of water quality exceedances within the required 72-hour time limit during cleanup of contaminated sediment at the GASCO site during fall 2005.

The stipulated penalty was part of a legal agreement between EPA and NW Natural to dredge a tar-mass from Willamette River sediment at the site of the former gasification plant. During the dredging, NW Natural used a geo-textile silt curtain to prevent sediments suspended by the dredging from being carried away from the site.

The water quality monitoring requirement was established by EPA to assess short-term impacts to fish and aquatic life. Work was stopped several times in order to take additional measures to protect water quality.

NW Natural entered a voluntary cleanup agreement with EPA in October 2004, to get a head start on cleaning up the highly contaminated GASCO site prior to the completion of the Portland Harbor investigation.

“The GASCO tar removal represented the first time contaminated sediment was dredged from the Portland Harbor Superfund site,” stated EPA Project Manager Sean Sheldrake. “The clean-up successfully removed a serious source of contamination to the Willamette River, but it also provided us with experience that will help minimise short term impacts during future sediment clean-up actions in the Willamette River.”