Contractors contained a 6,300 gallon oil spill discovered Monday at a XTO Energy Inc. onshore facility in Nikiski.
The spill was discovered at 4:30 p.m. Monday, and approximately 150 barrels of a mixture of 70-percent produced water and 30-percent crude oil spilled from a tank, according to Jeff Neu, XTO public and government affairs advisor.
All spilled fluids were captured within the secondary containment area, according to an Alaska Department of Environmental Conservation report.
“Bermed impermeable containment underneath and surrounding the tank prevented any potential soil contamination,” Neu said in an email.
A faulty gasket on an access plate, located on the side of the tank, leaked causing the spill. The access plate is used for tank inspection and maintenance when the tank is empty.
Upon discovery of the spill, oil flowing into the 5,000-barrel tank was redirected to other storage tanks at the onshore facility. The fluid levels in the tank were reduced to a level below the leaking access cover, according to the DEC report.
XTO officials indicated Wednesday morning that clean-up contractors began the final process of removing contaminated snow and ice from the containment area, said Mike Munger, Cook Inlet Regional Citizens Advisory Council executive director.
XTO has identified a recovery option in their 2011 contingency plan, which utilizes warm water from within the facility to melt the contaminated snow and ice within the containment area. Fluids recovered from this process will be reintroduced into the facility, according to the DEC report.
Contractors expect to complete clean-up efforts by Wednesday evening, and there are no plans for long-term monitoring of the incident, said Don Fritz, DEC project manager.