Spring Valley is home to a former World War I chemical weapons testing site where elevated levels of arsenic have been found in the soil.
The Corps is using a process called phytoremediation. Ferns are planted and the toxin is absorbed through their roots and stored in their leaves.
The ferns have been planted on approximately 15 percent of the contaminated properties including the Van Ness reservoir.
Manager Dan Noble says the pilot project does not involve excavating because it would require ripping up the yards of some very expensive homes. If tests show the ferns are not doing the job, the affected properties will be excavated.
WAMU 88.5 News Intern Peggy Wu reports...
Copyright 2008 WAMU 88.5 - American University Radio. All Rights Reserved.