RICHLAND, Wash. – EM’s Office of River Protection (ORP) tank operations contractor, Washington River Protection Solutions (WRPS), has awarded a subcontract worth about $14.5 million to construct a protective barrier above another group of large underground waste storage tanks at the Hanford Site.

Fowler General Construction, based in Richland, will install three sections of high-density, modified asphalt to form one large barrier over 18 tanks that make up the TX Tank Farm. Field work is expected to begin in March and be completed by the end of September.

“The surface barrier protects the environment by preventing rain and snowmelt from permeating into the soil and driving existing contaminants closer to groundwater,” said Richard Valle, ORP program manager for the project.

Constructed between 1947 and 1948, TX is the largest of Hanford’s 12 single-shell tank farms and will be the fourth tank farm with a surface barrier. The barrier will cover more than 220,000 square feet. Last fall, WRPS installed a stormwater collection system and a lined evapotranspiration basin to collect and evaporate water that drains from the barrier.

“The barriers are important for continued safe storage of tank waste,” said David Vasquez, WRPS project manager. “They improve tank and soil stability, and they significantly reduce surveillance and maintenance costs. Furthermore, they provide a safe, clean and stable platform for workers in the farm for years to come.”

The barrier will be constructed under an agreement between DOE, the Washington State Department of Ecology, and U.S. Environmental Protection Agency.