FREEMAN - About 10,000 tons of soil have been removed from the Freeman oil spill area during cleanup efforts, authorities said Wednesday.
Brian Walsh, an environmental scientist with South Dakota Department of Environment and Natural Resources' groundwater quality program, has been overseeing the cleanup by TransCanada Corporation to make sure it meets DENR requirements. Since the excavation of soil is ongoing, the amount of soil removed will increase, but the majority of the excavation is complete, Walsh said.
On April 2, TransCanada reported an oil leak to the National Response Center, indicating that a suspected 4.5 barrels-or 167 gallons-of oil had leaked. On April 7, the report was updated to estimate a leak of about 400 barrels-or 16,800 gallons.
TransCanada owns and operates the Keystone Pipeline, which originates in Hardisty, Alberta, Canada, to Patoka, Illinois, and separately to Port Arthur, Texas. It is a 30-inch pipeline that was constructed between June 2008 and March 2010.
Walsh expects cleanup efforts to be finished in the next couple weeks, but the project is weather-dependent, and TransCanada will ultimately have to continue cleanup efforts until it meets safety standards.
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As the soil is removed, it is tested for contamination until the excavated soil reaches levels that meet state standards. Walsh said excavation will continue until all contaminated material is gone. Petroleum contaminated soils are tested for five different chemicals.
The soil is being relocated to a landfill near Glencoe, Minnesota, operated by Waste Management, a common practice for petroleum-contaminated soil, Walsh said.
"They are familiar with proper disposal methods for hydrocarbon impacted soils," said Matthew John, a communications specialist at TransCanada. "This facility is recognized for having environmental protection systems in place to ensure that materials are appropriately contained and monitored."
Walsh said no groundwater or surface water was affected from the spill. The closest aquifer was 100 to 150 feet deep in the soil, and the oil spill penetrated approximately 10 to 15 feet below the pipeline, which sits about 70 inches beneath the soil surface.
According to the Corrective Action Order issued by the U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration, the nearest section of pipeline that could affect "high consequence areas" is approximately 1,400 feet downstream of the leak.
After the contaminated soil has been removed, the area will be backfilled with soil purchased from a local landowner.
John said the local landowners have been paid for temporary workspace rental, including areas to store topsoil and park vehicles and heavy equipment.
"In addition, directly affected landowners will be compensated for any actual damages they incur as a result of our activities," John said.
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This would include any possible income losses from affected land.
According to the CAO, the immediate cause of the leak was identified on April 7 as a girth weld anomaly positioned at the bottom of the pipeline.
This leak was discovered by an unidentified third-party metallurgist contracted by TransCanada.
Though the section of Keystone Pipeline was cut out and replaced by May 4, investigation is still ongoing into what caused the crude oil leak. The section of pipe is still being analyzed at an independent third-party agency to determine the cause of the leak, according to John. TransCanada would not release the name of the facility, but information about the incident will be publicly available through PHMSA once the investigation is complete.
The specific pipeline section that failed was installed in 2009 and was manufactured by Welspun. According to the CAO, it is unknown how long the pipeline had been leaking.
According to the PHMSA Corrective Action Order, "The investigation is ongoing and information could change."
In terms of the land affected by the pipeline, Walsh said once the soil is replaced with clean material and topsoil, the land should be restored to its use before the incident, and TransCanada will be responsible for any future issues arising from the spill.
