KENAI (AP) -- Tesoro Petroleum Corp. likely will excavate about an acre of contaminated soil to clean up a spill from the pipeline that carries refined fuels to Anchorage from its Nikiski refinery. The spill was discovered July 31 when Phillips Petroleum Co. workers found jet fuel on the ground near the buried Tesoro pipeline.
Just how deep workers will have to dig depends on the cleanup level Tesoro negotiates with the state, said Rod Cason, Tesoro Alaska vice president in charge of the refinery. There are naturally occurring hydrocarbons already present in the peaty soil, he said.
''You could dig forever and ever and not get to the bottom of it,'' Cason said.
The spill site is about 14 pipeline miles from the refinery inside Captain Cook State Recreation Area.
The 10-inch diameter pipeline, which carries jet fuel, diesel and gasoline, was shut down for four days while workers found the problem and welded a sleeve over three pinhole leaks discovered at a weld.
Ron Noel, Tesoro Alaska vice president and general counsel, said cleanup workers have collected 35,000 gallons of contaminated water, recovering 500 gallons of fuel from it. Workers brought 120 cubic yards of contaminated soil from the spill site to the refinery. Most of that was dug up to find and repair the leaks.
Gary Folley, an environmental specialist with the Alaska Department of Environmental Conservation, said officials from Tesoro, DEC, the Coast Guard and Alaska State Parks agreed last week that the best way to clean up the spill was to excavate the remaining contaminated area. Noel said that totals roughly 1.1 acres.
But how deep Tesoro must dig depends on what concentration of hydrocarbons the state agrees is acceptable in soil left in place at the site. Folley said state regulations set complicated methods for determining acceptable cleanup levels.
Noel said Tesoro expects to submit its remediation plan for state approval on Thursday. Then there will be a seven-day public comment period before the cleanup can proceed.
Cason said the excavation probably will take a couple of weeks.
Tesoro also must submit a plan for treating the contaminated soil. Cason said Tesoro probably will blend the peaty soil with gravel and burn it.
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