High levels of lead found in the water supply of Greenville, N.C. last year have caused state officials to announce testing on household faucets in four cities, including Durham. Starting next month, 100 sites in Durham will be tested by the North Carolina Division of Public Health for elevated levels of lead.
Officials found dangerous levels of lead in two Greenville children this May— a problem they believe was the result of the city’s drinking water. The problem was found after a switch in the chemicals used for treatment in Pitt County.
A new set of chemicals called chloramines may have caused water moving through pipes to become more corrosive, leaching lead from older sodder and plumbing parts.
Durham—one of four cities using a treatment combination similar to that used in Greenville—changed the chemicals it used about two years ago, said Durham Department of Water Management Director Terry Rolan.
Duke has not taken any major action to test for lead on campus.
“We rely on the city and the adequacy of their testing,” says Wayne Thomann, director of the Office of Environmental and Occupational Safety.
The University has a guarantee of good water from the city of Durham, and testing is generally only conducted when construction or other activities disturb the water supply, Assistant Director of OEOS Gary Tencer said. He added that there has been a “concentrated effort” on the part of Duke to remove any pipes with lead sodder.
Federal law requires municipal testing every three years, and Rolan is confident about the safety of lead levels in the water of Durham, which were last tested in September 2004. “Four samples out of 94 were higher than action level [15 milligrams of lead per liter of water],” he said—results which fall within the standards stipulated by the Environmental Protection Agency.
The municipal test consists of a running water test executed by the city and a standing water test done by homeowners on water that has been in their pipes overnight. Rolan stressed that no lead is present in water as it leaves the municipal pumps and any contamination present would have entered through the pipe system.
If testing reveals elevated levels, testing will be expanded in the city, homeowners will be encouraged to test their own water for lead and previous testing will be repeated to confirm results, said Kenneth Rudo, state toxicologist with the North Carolina Division of Public Health.
Ultimately, homeowners with lead problems can choose to replace the pipes at their own cost. But by running water for four to five minutes each morning and for 30 to 60 seconds before drinking to flush out lead which collects in pipes, high lead levels in tap water can be sidestepped, Rudo said.
However, any lead problem is difficult to solve for an entire system, noted Karl Linden, assistant professor of civil engineering.
“There’s no treatment at that point because [any lead] is in the home systems.”
Plain chlorine was previously used to treat water, but it was believed to react chemically with organic materials in water to form carcinogens. The city also uses zinc orthophosphate—an anticorrosive agent which prevents the leaching of lead into water—to treat the water supply, which may mitigate the additional destructiveness of chloramines.
Lead poisoning causes damage to the nervous and reproductive systems and can result in vision and hearing impairment in adults. The effects of lead poisoning can be more dire in children, resulting in mental retardation, liver damage and death, in extreme cases. Children are also more likely to ingest materials containing lead from soil to paint chips.
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