This 8.9-hectare (21-acre) irrigation system was developed in 2000 as a collaborative effort between SREL, USDA Forest Service, and Savannah River Nuclear Solutions for phytoremediation, or the use of plants, to clean up or reduce the level of tritium, a radioactive form of hydrogen, released into Fourmile Branch. The tritium cycled here originates from the Savannah River Site’s mixed-waste burial grounds.
Tritiated groundwater surfaces as a seep above Fourmile Branch and it is impounded by a dam that irrigates natural forest vegetation uphill, absorbs, and then transpires it. Any unabsorbed irrigated water sinks below the root zone and returns to the collection pond via the seep.
Since its operation, the system has reduced tritium concentration in the waters released into Four Mile Branch by more than 50 percent.
The facility is equipped with an automated sampling system (AVMS) to monitor soil conditions at regular intervals.