COLUMBIA, S.C. — The U.S. Army is trying to determine whether pollution is spreading from Fort Jackson to nearby drinking water supplies or if past military activities off the base caused private well contamination in the area southeast of Columbia.
What military officials learn could help determine how to stop the groundwater pollution threat, including digging up and removing contaminated soil.
About 18,500 acres south of Fort Jackson were leased by the army training base more than 50 years ago, but the land today is sprinkled with homes and small businesses. The area under investigation is mostly east of the base’s Weston Lake, between Leesburg Road and Garners Ferry Road.
Army officials are investigating how the 18,500 acres south of the base were used historically by Fort Jackson — most notably whether explosives were detonated on the land.
A chemical known as RDX, a key ingredient in hand grenades, has shown up at elevated levels in two wells serving five homes south of Fort Jackson. RDX can cause seizures in people who drink water contaminated with the material.
“Our goal is to do a complete and thorough assessment, and having historical training information will greatly assist us in that effort,’’ the base’s environmental division chief, Barbara Williams, said in an email Friday night. “The results of the search will be shared with the public once we receive it.’’
While the pollution could be coming from private land formerly leased to Fort Jackson, the fort has identified RDX contamination on the southern edge of the property. So it’s possible that the fort could be the cause of the off-site well pollution. For now, drinking water on the base does not show elevated contaminant levels, Williams’ email said. Lakes and creeks have not shown levels of RDX or other explosive contaminants that pose a health risk, she said.
Base officials have refused to identify the location of the private wells with elevated RDX levels, citing privacy concerns.
But Patrick Jones, a base spokesman, said people with polluted wells have been notified and are aware of the threat.
“There is some concern,’’ he said. “They are not freaking out. We’ve said, to start with, ‘Let us provide you with bottled water.’ And (the base is ) pursuing trying to do whole-house filtration’’ systems to protect drinking water.
Fort Jackson has hired a private water company to deliver bottles to the affected homes every two weeks. The deliveries began May 21.
Whether the pollution could affect other wells in the area is unknown, but the fort plans more well tests beginning next week, Williams said, noting that the fort is encouraging people to seek testing.
Fort Jackson verified well contamination in several homes in January after discovering groundwater pollution last year. But as of early February, the fort had not found unsafe levels of RDX or other chemicals in drinking water, state regulators said.
Base officials then conducted follow-up tests this past spring and discovered that RDX levels exceeded the EPA limit of 2 parts per billion in two wells. The fort outlined the problem during a public meeting earlier this week. The base also found traces of two other chemicals, but not at elevated levels, officials said.
The 18,500-acre area south of Leesburg Road that is under investigation is a sizable chunk of land. The property is about one-third the size of the 52,000 acres that today make up Fort Jackson. Another 10,000 acres on the other side of the base were leased to the fort at one time. Maps provided by Fort Jackson indicate that property was near Percival Road.
The S.C. Department of Health and Environmental Control, which was critical of the fort’s investigation last fall, says it is monitoring Fort Jackson’s probe. Agency spokesman Mark Plowden said Friday the Army has taken “proactive steps” to study historical use of the land around the fort’s current boundaries.
Fort Jackson is the country’s largest army training base. Some 44,000 soldiers train there each year.