The radioactive pollution near the 41-year-old waste burial ground near Barnwell contains tritium at a higher level than that permitted by federal safe drinking-water standards, Columbia's newspaper, The State, reported Sunday.
The state's Department of Health and Environmental Control, however, says the site is generally stable and no one is drinking the polluted water. Energy Solutions, the operator of the dump, agrees.
South Carolina historically had been willing to accept the nation's low-level nuclear waste. In 2008, however, the dump was closed to states except South Carolina, New Jersey and Connecticut, The State said.
During the Governor's Nuclear Advisory Council meeting last week, state regulators said pumping tritium out of groundwater or from a creek might contribute to air pollution as the tritium was expelled.
They also said dump excavation could be more dangerous than leaving waste in place.
"It's not likely you would dig into that because you would be exposing individuals to radiation," Susan Jenkins, head of DHEC's infectious and radioactive waste division, said.
Jenkins said DHEC has considered a cleanup that would rely on phytoremediation, which entails planting trees with deep tap roots to suck up the polluted water. No decision has been made yet on that strategy, she said.
At least one federal agency has taken action in light of the tritium threat. Jim Giusti, a U.S. Department of Energy spokesman, said a federal nuclear-weapons complex -- the nearby Savannah River site -- has pumped tritium from water in some places and put pollution control barriers in place.