On Site Soil Remediation at Weyerhaeuser 1-29 Exploration Well Site

This was the site of Amoco Production Company's Weyerhaeuser 1-29 Exploration Well. The site was located approximately 20 miles northeast of Aberdeen, Washington, and was only assessable by logging roads. A reserve pit containing approximately 18,000 cubic yards of used drilling mud (bentonite cut with # 2 fuel oil) had been left on-site after exploration well activities were completed. The reserve pit and surrounding area was investigated and found to contain hydrocarbon concentrations well above cleanup levels.

Excavated drilling mud and soils were impacted by petroleum hydrocarbons in concentrations ranging from 1,000 mg/kg to 130,000 mg/kg, with the average near 10,000 mg/kg. In addition another contractor had added approximately 1,000,000 gallons of water to the soil in a failed attempt at soil washing. Consequently, soil moisture contents were extremely high, ranging from 30% - 45%. The contract included responsibility for all regulatory permitting and site work, including the excavation of 40,000 cubic yards of used drilling mud, contaminated soil, and over burden, dewatering and thermal treatment of used drilling mud and contaminated soils, backfilling and site restoration.

Project Performance

All contaminated soil was thermally treated to less than 7 mg/kg at an average process rate of 30 tons per hour. Despite logistical challenges posed by the remote location and performing thermal remediation in the rainy season, the project was completed under budget and ahead of schedule.