EPA rebuts Durham on lead test

The federal agency differs with the city on removing aerators before taking water samples

DURHAM -- Federal regulators have issued a nationwide advisory on how to properly screen for lead in drinking water after learning that Durham was instructing homeowners to remove aerators from their faucets before drawing samples.

In an Oct. 20 letter, the U.S. Environmental Protection Agency's director for Drinking Water Protection, Stephen Heare, effectively barred the practice, which Durham has done since it began the mandated tests for lead in 1991.

"Removing and cleaning of the aerator is advisable on a regular basis. However, if customers are only encouraged to remove and clean aerators prior to drawing a sample to test for lead, the public water system could fail to take additional actions needed to reduce exposure to lead in drinking water," Heare writes. "Therefore, public water systems should not recommend that customers remove or clean aerators prior to or during the collection of tap samples for lead."

In its written directions, Durham instructs homeowners participating in the lead-detection program to remove the aerator and run water from the faucet the night before collecting the requested sample. After filling the container, the customer is asked to reinstall the aerator.

This procedure effectively boosted the likelihood Durham residents would collect clean samples, thereby increasing chances the city would meet federal drinking water standards.

Lead can cause developmental difficulties and brain damage if consumed by children or pregnant women. The toxic metal leaches from old plumbing fixtures and pipe solder -- a process that can be hastened if a city provides water that is too corrosive.

Durham's water chemistry has been under scrutiny since April, after a child was found to have lead poisoning. Water drawn from the South Durham apartment where the child lived was found to contain the toxic metal in concentrations nearly 60 times the federal safety limit.

Further testing by the city and the county Health Department found lead in water from dozens of homes scattered across Durham. Drinking fountains at eight schools were disconnected during the summer after lead was found in unacceptable amounts.

Questions about Durham's testing procedure were raised earlier this year by Marc Edwards, a Virginia scientist hired to test the city's water by the owners of the apartment complex where the child was poisoned. Edwards said removing the aerator before testing could remove trapped lead particles, overlooking a possible source of contamination.

When The News & Observer contacted the EPA about the practice in June, federal regulators said they were unaware that any water system had made removing aerators part of its testing procedures. EPA guidelines for proper testing made no mention of aerator removal. Federal officials said at the time they would review the practice to see whether it could affect the integrity of the testing.

Though aware federal regulators had concerns, Durham officials still included the step in procedures for a round of lead testing in September. Durham announced this week that it had passed those tests.

"We were aware that EPA was reviewing the aerator 'on' versus 'off' issue but were not sure when any final directive would be issued," Vicki Westbrook, spokeswoman for Durham's water management department, said in an e-mailed response Friday. "Certainly we will incorporate any EPA and state revisions [or] advisories into our sampling protocol for any future lead ... compliance testing."