On July 8, 2009, at approximately 5:45 hours, a tanker truck and trailer reportledly lost control and crashed in the eastbound lane of Highway I-84 on a bridge over McCord Creek, in Multnomah County, Oregon. The truck and trailer were carrying approximately 3,000 gallons and 5,000 gallons, respectively, of asphalt oil (asphalt cement). The crash resulted in the truck discharging its entire contents onto the road surface, down through the bridge's drainage system, and also over the bridge into McCord Creek and its banks. The heated paving asphalt had a low viscosity allowing it to easily flow though the bridges’ drain system and onto the ground and McCord Creek below. Once in the creek, the paving asphalt cooled rapidly, and solidified into a ductile solid similar to salt-water taffy or silly putty. None of the asphalt oil in the trailer was discharged. Oregon State Police, Cascade Locks Fire Department, Gresham Hazmat, and the Oregon Department of Transportation (ODOT) responded to the incident, and the eastbounds lanes of I-84 were shut down. ODOT also mobilized its clean-up contractor, NRC Environmental Services, to the site.
The Oregon Department of Environmental Quality (ODEQ) and EPA responded to the incident immediately after notification, and entered into unified command with the Responsible Party (RP) and ODOT in order to begin mitigation of the spill. The RP contracted with the NRC in order to conduct site clean up and oil removal activities. Other responding agencies included the Confederated Tribes of the Warm Springs Reservation and U.S. Coast Guard, Sector Portland. No injuries or fatalities were reported to have occurred during the accident.
McCord Creek flows directly into the Columbia River within approximately 1/2 mile of the spill site. No sheen or asphalt was observed at the mouth of the creek or in the Columbia River, and there were no observable immediate impacts to fish and wildlife.
Once on site, EPA, Granite Northwest, Inc., ODEQ, NRC, and ODOT, took a site tour and discussed cleanup options, especially in regard to consideration of potential effects to threatened and endangered sensitive species, and historical/cultural areas. Consultation with the State Historical and Preservation Officer (SHPO) was conducted, and it was agreed that an archeologist needed to be present during removal activities. The agencies also contacted Oregon Department of Fish and Wildlife (ODFW) and NOAA National Marine Fisheries Service to request site visits and consulations. During this meeting, Richard Craig, representative of the Confederated Tribes of the Warm Springs Reservation of Oregon arrived. Several cleanup methods were proposed, however it was agreed upon that no action would occur within the creek and riparian zone until the Oregon Department of Fish and Wildlife (ODFW) arrived to consult.
Glenn Littrell, a representative from Oregon State Parks and Recreation (OSPR) arrived on site. Two representatives from arrived on site to provide guidance as to the types of sensitive fish species which may be present in McCord Creek and also to discuss the cleanup goals and methods.
Subsequent to this meeting it was agreed to try to remove the hardened paving asphalt via hand removal without any isolation or diversion of the creek and/or aquatic organisms.
At 1800 hours, NRC completed the first attempt to manually remove the hardened paving asphalt without conducting any excavation. NRC found that the asphalt had not penetrated deeply into the creek substrate, however, removal of the ‘asphalt chunks’ was cumbersome and difficult. Additionally, small fragments of the hardened paving asphalt were created during removal of the larger pieces. The smaller fragments were then transported downstream by the current. NRC recommended capturing the small fragments with a screen or mesh net on the stream bed during future removal. Additionally, NRC recommended the use of machinery on the stream bank to assist with the manual removal of the heavier pieces of hardened paving asphalt.
Removal activities will continue on June 9, 2009. The RP will order more personnel and equipment in order to facilitate effective removal of the oil.
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