WorldWide Drilling Resource

27 APRIL 2022 WorldWide Drilling Resource® Tree Farm Steers Contaminants from Waterways Adapted from Information by the U.S. Department of Energy’s Office of Environmental Management From its inception in the early 1950s until the end of the Cold War, Savannah River Site (SRS) produced tritium for use in manufacturing nuclear weapons. Scientists in the Environmental Management (EM) program are now using a 62-acre pine tree farm and other natural resources to keep radioactively contaminated groundwater from reaching waterways on SRS. The trees effectively act like a forest of tall hydraulic pumps, each drawing up irrigated water containing the contaminant tritium pumped from a nearby holding pond, and harmlessly releasing it into the atmosphere through photosynthesis. “With this project, we learned a lot about harnessing nature to continually move towards passive, low-energy, and sustainable cleanup technology with minimal cost,” said Philip Prater, senior physical scientist with the U.S. Department of Energy-Savannah River. “And it’s accomplished effectively without the generation of any waste.” The extensive irrigation system uses piping and sprinkler heads to evenly spread tritiated water over forest floor debris. Large-scale evaporation also takes place during this process, releasing additional tritium into the atmosphere. “We knew that capturing and containing the contaminated groundwater seeping to the surface and into a manmade pond would greatly limit this flow from eventually reaching the Savannah River,” said Jeff Thibault, an engineer with Savannah River Nuclear Solutions (SRNS), the site’s management and operations contractor. “However, the challenge was, how do you keep it from overflowing? We do so through the pine plantation’s irrigation system, which is extremely effective.” U.S. Forest Service-Savannah River (USFS-SR) researchers and engineers with the EM program began designing this interim treatment in 1999 with the goal of reducing the amount of tritium reaching a creek named Four-Mile Branch by 25%. Since 2001, when the treatment began, approximately 190 million gallons of water - including nearly 7000 curies of tritium that otherwise would have entered the Savannah River - has been sprayed throughout thousands of loblolly pine trees. “Traditional remediation costs associated with this level of tritium removal would be close to $220 million dollars over a 20-year period,” said Marsue Lloyd, USFS-SR civil engineer. “Our costs over that same span of time for this project are approximately $12 million dollars.” At EM’s Savannah River Site, U.S. Forest Service employees inspect irrigation piping and sprinkler heads at a 62-acre pine tree farm. ENV Tree Farm continued on page 32.

RkJQdWJsaXNoZXIy NDk4Mzk=