A second mobile home park near Shaw Air Force base is registering elevated levels of toxic chemicals, prompting questions about the possible spread of pollution from the military base across a wider area of Sumter County.
The S.C. Department of Health and Environmental Control, which said the contamination likely came from Shaw, released test results Thursday showing that per- and poly-fluroalkyl pollution in drinking water at the American Mobile Home Plaza exceeded a federal health advisory level. The Sumter-area mobile home park has 181 residents.
Thursday’s test results are the second released in a week showing that per- and poly-fluroalkyl substances, a class of chemicals of growing concern nationally, are tainting drinking water outside the base property.
All told, two mobile home parks serving nearly 450 people are confirmed to have the chemicals in their drinking water. The U.S. Department of Defense has already confirmed that groundwater at Shaw Air Force Base has been polluted by PFA compounds, possibly from fire-fighting foam the based used.
The state’s test results in wells at American Mobile Home Plaza and Crescent Mobile Home Park are among the first to show pollution from per- and poly-fluroalkyl substances in a public water system in South Carolina, officials say.
The pollutants, commonly referred to as PFAS, are a class of chemicals with an array of potential health effects. While research is ongoing, they are suspected to cause cancer and kidney problems, as well as developmental issues in children. People exposed over a period of years are considered most at risk.
With drinking water contamination showing up in tests at the two mobile home parks, DHEC and Shaw Air Force Base will now begin checking other area public and private wells that are in the path of the groundwater flowing off the military installation to see if more communities are at risk, officials said. The agency said last week it planned to check all major water systems in the state at some point for PFAS.
In Sumter County, the air base will test public and private wells within one mile south of the base, while DHEC will test public wells beyond one mile, according to a Shaw statement and DHEC water bureau chief Mike Marcus.
Among the wells to be tested by DHEC are three that supply the city of Sumter’s drinking water system, the largest in the area. So far, tests have not shown problems with the Sumter system, Marcus said.
Shaw Air Force Base, a key cog in the nation’s defense, lies in a sprawling area of Sumter County that contains a mixture of suburbs and rural communities about 45 miles southeast of Columbia. Much of the county’s drinking water comes from groundwater.
Shaw’s testing will begin next week to see if other wells in the area exceed the U.S. Environmental Protection Agency’s health advisory standard of 70 parts per trillion in drinking water, officials said.
“Beginning February 10, 2020, the Air Force will be conducting sampling of drinking water wells up to one mile south of Shaw Air Force Base to test for potential impacts from PFOS/PFOA,’’ Shaw said in a statement Wednesday, referring to two of the most common types of PFAS.
“Our focus is on ensuring no one is drinking water above the EPA’s 70 parts per trillion lifetime health advisory and if the Air Force identifies drinking water sources with PFOS/PFOA at levels above the EPA’s (health standard), we will take immediate steps to provide alternate drinking water supplies.’’
In an email late Thursday afternoon, Shaw said the base believes it was a “likely contributor’’ to the presence of two key types of PFAS found in wells at the Crescent and American mobile home parks. The parks are 500 to 1,200 feet from the southern edge of Shaw Air Force Base, the email said. Drinking water on the base has not been contaminated at levels exceeding the federal health advisory standard, the base said.
A key question with PFAS contamination centers on how long people at the two mobile home parks were exposed to the contaminants since the chemicals pose a threat to people over the long-term.
Erik Olson, who tracks PFAS issues for the Natural Resources Defense Council, said DHEC’s findings are part of a growing national problem that needs to be addressed.
“It’s not a huge surprise that a military base will have contaminated groundwater or soil,’’ he said. “What’s concerning is it’s getting off base. That’s where you start seeing pretty serious health concerns’’ when the level exceeds the EPA health advisory standards. Olsen said the mess needs to be cleaned up to protect people’s health.
State Rep. JA Moore, a Democrat from the Charleston area, said the latest test results in Sumter raise concerns about pollution from per- and poly-fluroalkyl substances in other parts of South Carolina. He has introduced legislation that would for the first time set a state limit on the amount of PFAS allowed in drinking water. The EPA’s health standard is an advisory, not a limit.
“We’ve got to act,’’ Moore said. “What we are going to find is this isn’t just Sumter. As they do these studies it could be an epidemic throughout our entire state.’’
Groundwater contamination by PFAS has been closely associated with military bases that, beginning in the early 1970s, used fire-fighting foam containing some types of the chemicals. Use of the foams that contain PFAS has been curtailed at military bases.
In South Carolina, groundwater contamination has been found at Shaw, as well as at the old Myrtle Beach Air Force Base, the Charleston joint military base and the the National Guard’s McEntire air base southeast of Columbia, according to Department of Defense reports. It is not known whether wells near those sites have been contaminated.
In addition to use in firefighting foams, PFAS also were widely used in a variety of products, including non-stick cooking pans, cosmetics, dental floss and stain resistant carpets.
For now, DHEC officials said they are providing carbon filters to the 78 homes at American Mobile Home Plaza that are affected by the pollutants to filter out the contamination. Contamination in the American Mobile Home Plaza water was roughly twice as high as that found at Crescent Mobile Home Park, Marcus said.
Last week, the agency provided filters to residents at the Crescent Mobile Home Park, also near Shaw Air Force Base, after finding levels of PFAS pollution above the health standard. The base supplied bottled water to Crescent residents.
Levels found at both Crescent and American Mobile Home Plaza exceeded the U.S. Environmental Protection Agency’s health advisory level of 70 parts per trillion in drinking water. American Mobile Home Plaza, which had higher levels than Crescent, showed some levels exceeding 200 parts per trillion, records show.
American Mobile Home Plaza, like Crescent, has its own water system regulated by DHEC. American Mobile Home Plaza recently received an unsatisfactory rating from DHEC for how it operates the system, records show. Attempts to reach an official with American Mobile Home Plaza were unsuccessful Thursday.
DHEC’s drinking water tests followed laboratory tests conducted for The (Charleston) Post and Courier that found elevated PFA levels at the Crescent Mobile Home Park.
“The health of our communities remains the top priority for DHEC,’’ agency spokeswoman Jennifer Read said in an email. “We are urging Shaw Air Force Base to continue their investigation of any potential offsite impacts to nearby water systems. In the meantime, we have provided carbon filters to the residents impacted in these two communities and will continue to keep them updated as we learn more.’’
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