COLUMBIA, SC — Radioactive pollution is getting worse on parts of South Carolina’s nuclear-waste dump near Barnwell, but state regulators say cleaning up the contaminated groundwater isn’t in their plan.

Tritium continues to exceed federal safe drinking-water standards in and around the 41-year-old burial ground that has come to symbolize South Carolina’s historic willingness to accept the nation’s garbage. In some spots tritium levels are higher today than they were five years ago.

But the S.C. Department of Health and Environmental Control says the site is stable overall and no one is drinking the polluted water. So for now, the agency has no plan for a tritium cleanup. The dump’s operator, Energy Solutions, agrees.

Pumping tritium out of groundwater or from a radiation-tinged creek would possibly contribute to air pollution as the tritium was expelled, state regulators said. At the same time, excavating waste from the dump could be more dangerous than leaving it in place, state regulators said during the Governor’s Nuclear Advisory Council meeting last week.

“It’s not likely you would dig into that because you would be exposing individuals to radiation,” said Susan Jenkins, who heads DHEC’s infectious and radioactive waste division. “That is not something we would probably want to do.”

Since the low-level nuclear-waste dump opened in 1971, tritium has leaked from unlined burial pits, contaminated groundwater and trickled into a creek a half-mile away. The dump closed to the nation in 2008 but still is open for South Carolina and two other states’ waste. A small neighborhood that relies on wells is just downhill from the creek, although Jenkins said radioactive material is not polluting the wells.

Jenkins said her agency has discussed a cleanup that would rely on “phytoremediation.” That involves planting trees with long tap roots to suck up the tritium-polluted water. But no decision has been made on that idea, she said.

While groundwater cleanups can cost millions of dollars, at least one federal agency has taken on the challenge in South Carolina because of the threat of tritium.

The Savannah River Site, a federal nuclear-weapons complex next to the Barnwell site, has pumped tritium from water in some places and installed barriers to control the spread of pollution, said Jim Giusti, a spokesman for the U.S. Department of Energy.

The department also has used plants to absorb tritium from water on the SRS property, he said. Giusti said such decisions are usually dictated by comparing the cleanup cost to how serious the contamination levels are.

Bob Guild, a lawyer who is suing the state on behalf of environmentalists to require improved disposal practices at Barnwell, said DHEC should follow DOE’s lead and remove the threat from the state-owned nuclear-waste dump. He said Energy Solutions of Utah, the dump’s operator, should be responsible for the cost.

“The burden should be on them to stop the contamination,” Guild said.

Energy Solutions spokesman Mark Walker, whose company acquired long-time site operator Chem-Nuclear several years ago, said the pollution levels don’t warrant a cleanup.

During the meeting Thursday, DHEC’s Jenkins presented data showing that tritium levels are rising at seven key points at the Barnwell site, while falling at nine others. At 11 other monitoring wells, there has been no trend recently, she said. In an interview Friday, she characterized the site as stable.

Among the data:

• In the oldest part of the Barnwell landfill, tritium levels have been found recently that exceed 29 million pico curies per liter of water. But that’s more than 1,400 times higher than the Environmental Protection Agency’s safe drinking water standard of 20,000 pico curies per liter, according to data reviewed by The State newspaper last week. The current reading is about 2 million pico curies higher than in 2007, DHEC records show.

• In Mary’s Branch, a small creek just below the site, tritium levels exceeded 500,000 pico curies per liter. That meets the federal Nuclear Regulatory Commission radiation standard DHEC must ensure the site complies with. But it’s 25 times higher than the EPA’s standard for safe drinking water, The State found. Tritium levels at Mary’s Branch are roughly the same as they were in 2007, records show. The creek flows into the Savannah River.

Tritium is a fast-moving radioactive pollutant that has been linked to certain forms of cancer in people who drink water containing large quantities of the material. But it also can indicate the flow of more toxic contaminants that are expected to move in groundwater later. Substances such as uranium and plutonium are among those.

Environmentalists who attended Thursday’s meeting said the tritium pollution is a continuing concern. Among those was nationally known singer Jesse Colin Young, a founder of the 1960s-era folk-rock group the Youngbloods.

“I have to admit I was a little horrified by the tritium plume,” said Young, who lives in the Aiken area.

The 235-acre nuclear-waste dump, which began operating in 1971, for decades took the nation’s low-level atomic garbage. At the time it closed to the nation in 2008, the Barnwell County site was the only atomic-waste landfill that took all classifications of low-level waste from across the country.

The Legislature closed the site to all but South Carolina and two other states, New Jersey and Connecticut. For years, the state Legislature, under pressure from Chem-Nuclear, had continued to push back closure dates for the site because of the revenues generated for state government for dumping atomic waste.

Situated in the soggy ground of central South Carolina, the Barnwell dump sprang leaks not long after it opened. Tritium seeped into groundwater from unlined trenches.

State regulators assured the public for years that the site posed no danger to drinking water or the nearby Savannah River. But the agency never released data showing the extent of the pollution or where it was located until The State newspaper challenged the department in 2007.

Pollution maps released by the agency at the time showed that some contamination at the Barnwell dump exceeded that of the nearby Savannah River Site, which typically deals with much higher levels of radiation in waste material. The newspaper also identified a small neighborhood downhill from the leaking dump that had not been mentioned by state regulators in public meetings.

Today, the site still disposes of waste in much the same way it always did, although some improvements have been made to try and keep rainwater out of the trenches. It takes tritium about 120 years to break down completely in the environment.