Cement factories, including one near Harleyville, are much bigger mercury polluters than previously thought — worse in some cases than coal-fired power plants, a study by two environmental groups found.
Using new data collected by the Environmental Protection Agency, the analysis by Earthjustice and the Environmental Integrity Project also found "mercury accounting gaps" that raise questions about whether cement companies properly report pollutants from their plants.
Prodded by lawsuits, the EPA collected data last year from nine cement companies about how much mercury-laden fuel their kilns burn.
Based on this data, the EPA recently estimated that cement kilns nationwide pump out about 23,000 pounds of mercury, almost twice their previous estimate of 12,000 pounds.
That means cement plants are among the worst mercury polluters of any kind in the country, said Eric Schaeffer, a former EPA director and founder of the Environmental Integrity Project.
Mercury is a potent neurotoxin known to cause health problems in tiny amounts. Released during the combustion process, mercury emissions land in waterways and begin their trek up the food chain, building up in fish and people who eat them.
State health officials have found high levels of mercury in fish in more than 1,700 miles of South Carolina rivers, mainly in the coastal plain, and in coastal waters. In last year's series, "The Mercury Connection," The Post and Courier identified several areas where fish have particularly high concentrations of mercury.
One of these hot spots was in the Edisto/Four Holes Swamp area, home to a Scana coal-fired power plant and cement operations run by Lafarge and Giant Cement.
In their study, Earthjustice and the Environmental Integrity Project said Lafarge's Harleyville plant annually burns materials containing 206 pounds of mercury, but that the company told federal regulators it released only 78 pounds.
Because mercury is an element, it isn't destroyed in the burning process. "It has to go somewhere," said James Pew, an attorney with Earthjustice.
Lafarge's plant manager, Scarth MacDonnell, called the groups' calculations "irresponsible. There's a big sense of fear that it's three times what we say, but we've done our homework."
MacDonnell said that his staff tests emissions from the plant's stacks to reach the 78-pound number, and that they also did calculations using EPA's new methods. "We validated within a margin of error our stack test of 78 pounds, so we don't think the 206 pounds is a valid number." Pew said the groups received their data about Lafarge and other cement factories from the EPA, which collected it from the company. He said the 206-pound estimate represented the upper bounds of what the plant likely emits.
Giant Cement wasn't included in the study and reported emitting 33 pounds of mercury in 2006. That plant burns hazardous wastes, while Lafarge burns coal and nonhazardous wastes.
Officials with Giant Cement could not be reached for comment late Wednesday. Earlier this month, DHEC reported that it had fined the company $34,000 for failing to implement sufficient dust-control measures and properly certify eight routine monitoring reports.
The environmental groups want cement companies to install better pollution control and continuous-monitoring equipment.
"It has taken EPA forever to get to this problem," said Schaeffer, who left his job as director of EPA's Office of Regulatory Enforcement in 2002 over frustration with what he said were the Bush administration's efforts to weaken the Clean Air Act and other laws.
Reach Tony Bartelme at 937-5554 or firstname.lastname@example.org.