Tar Cleanup Scheduled for Portland Harbor

PORTLAND, Oregon, May 4, 2004 (ENS) - Tar-laden sediment will be removed from the Willamette River this summer under an agreement between the U.S. Environmental Protection Agency (EPA) and Northwest Natural Gas. The contaminated sediment lies along the river bottom beside the former Portland Gas and Coke Company (GASCO) site in Portland Harbor. Northwest Natural Gas currently owns and operates the site.

The GASCO project is the second early action agreement for the Portland Harbor Superfund Site. It is the first underwater removal of contamination since Portland Harbor was added to the Superfund List in 2000.

The tars contain polynuclear aromatic hydrocarbons and benzene. The EPA has determined that removal of the tars is "time-critical and needs to take place quickly to reduce the possibility of releases of hazardous substances from the tar-body into the Willamette River and downstream areas."

The Administrative Order on Consent that the EPA and Northwest Natural signed this week commits Northwest Natural Gas to develop a work plan within 30 days, with the goal of completing removal of the tar in the river this summer, at times when the least impact to migrating salmon would occur.

GASCO built and operated an oil gasification plant on the site between 1913 and 1956. From 1913 to 1941, waste and by-products from various gas production operations were discharged to a stream channel to the Willamette or low-lying areas of the site.

From 1941 to 1956, wastewater effluent and tar still bottoms or residuals were disposed of in settling ponds.

Some 30,000 cubic yards of tar waste had accumulated by the time the plant was shut down and the ponds were buried under 10 feet of fill in 1973.

According to the Oregon Department of Environmental Quality (DEQ) the oil gasification wastes include tars, oil, creosote, phenols, polynuclear aromatic hydrocarbons, BTEX and lead.

"Contamination at the site may represent a threat to human health and the environment by migrating to the Willamette River," the DEQ says.

"Northwest Natural is doing the right thing by agreeing to remove a known source of contamination in the river," said EPA Regional Administrator John Iani. "In addition, the GASCO tar-body removal is responsive to public desires to get an early start on cleanup where it is possible."