RICHLAND, Wash. – EM’s Hanford Office of River Protection (ORP) took another step forward in protecting the environment and enhancing worker safety by installing an interim surface barrier in SX Tank Farm.
The barrier, constructed by Hanford contractor Washington River Protection Solutions (WRPS), is a temporary structure that prevents rain and snowmelt from leaching into the underground waste tanks, percolating into the soil and driving contaminants toward groundwater.
“Surface barriers improve tank and soil stability, reduce surveillance and maintenance costs, and create a clean and stable platform for field workers,” said Brian Harkins, ORP deputy assistant manager for tank farms. “The interim barrier, which satisfies a Tri-Party Agreement requirement, will remain in place until a final farm closure plan is determined.”
Made of high-density asphalt, the barrier drains water to an evaporation basin. The project team constructed the barrier in three sections. The team completed the first two sections last fall and the third section a week ahead of its deadline earlier this year.
It took nearly 5,000 tons of asphalt and 6,400 tons of gravel to construct the 230,000-square-foot barrier. Workers also installed three stormwater vaults and 1,100 feet of drain piping.
“Installing the barrier allows us to increase safety and reduce the radiological classification of the area,” said Jim Geary, manager of the WRPS tank farm projects organization.
Prior to constructing the barriers, the team built an evaporation basin roughly the size of two football fields south of SX Tank Farm. The project involved excavating about 28,000 cubic yards of earth and installing a series of drain pipes on a special liner in the basin floor. Crews then installed a mix of native plants and grasses to help evaporate the water.
“As is the case with many large projects, the prep work was the key to success,” Geary said. “Removing all of the old equipment, excavating for the drain lines … there was a lot of hard work that was done even before we could start to lay asphalt. Excellent job by the entire team.”
SX Tank Farm is located in the 200 West Area of the Hanford Site and contains 15 tanks, each with a capacity of 1 million gallons. It is the third of Hanford’s tank farms with surface barriers, T and TY tank farms being the other two.