Back in July, the Virginia Health Department learned that the Lucketts Community Center's water supply was contaminated with lead.

But no one alerted the center's employees, and no one told the parents of children who attend a preschool there.

For nearly three months, people kept drinking and using the water.

Not until Oct. 11 did Hugh Eggborn, field director for the department's office of drinking water, alert the Loudoun County Sanitation Authority about the lead contamination.

It was nearly three more weeks before parents of the preschoolers were told through bulletins and take-home fliers, which also notified them of coliform bacteria found in the water.

The community center, which has a well water system, shut off its pipes and has been using bottled water since.

As the news spread last week, county officials tried to soothe anxious residents. David Goodfriend, director of the county health department, noted that lead poisoning through tap water is highly uncommon. Supervisor Sarah R. "Sally" Kurtz (D-Catoctin), whose district includes the Lucketts center, said Friday, "I don't know that there's quite the need for concern that was felt at first."

Nevertheless, some supervisors and angry parents are seeking an explanation from those involved.

Eggborn, asked Friday whether he could explain the delay in making his report, repeatedly declined to answer. He did say, however, that when the lab results were sent to him, a copy was mailed at the same time to a county office building in Leesburg.

The sanitation authority presumes the delay was caused by a switch this summer in who was responsible for the center's well, spokeswoman Samantha Villegas said Friday. The authority took over in June from Loudoun County General Services.

Kurtz, who was among those in the county who did not learn of the contamination, agrees with that analysis.

"When LCSA took over, there was a gap there," she said. "When there was a question, those responsible should have told the board."

The state requires lead tests twice a year and bacterial tests once a year for untreated water.

One of the five sites sampled in June, a tap for hand-washing, yielded a reading of .022 milligrams of lead per liter of water, the county said Wednesday. The Environmental Protection Agency considers .015 milligrams per liter the "action level" above which an agency must take corrective steps.

Villegas said separate tests found coliform bacteria in untreated, non-drinking water, which indicates fecal contamination of the well. She said no alert was issued because follow-up tests were inconclusive until October.

Lead poisoning and exposure to coliform can be extremely hazardous, even deadly, particularly for younger children. And lead poisoning can cause brain damage in children.

"Any time you have an elevated level, it's something you should be concerned about," Goodfriend said. "Even if it's at a location where people don't drink, it's a good idea to see why the lead level is at that location."

The likely cause is lead solder or lead in water fixtures, Alan Brewer, the county's chief of environmental health, told county officials in an e-mail Wednesday.

LCSA will conduct subsequent tests, Villegas said, and if the problem resurfaces, the authority will consider replacing pipes or using a substance to inhibit corrosion.

"If a parent is concerned, we would encourage that they have a conversation with their pediatrician," Goodfriend said.

As for the coliform contamination, the most likely source is surface or runoff water, Brewer wrote in his e-mail.

Eggborn's office has stipulated several requirements, including installing a filtration system and enhancing the disinfection system by Oct. 31, 2006. If the problem persists, LCSA could replace the well or connect to a nearby water source that isn't contaminated, Eggborn said.