Small water fountains and sinks are the likely cause of unacceptably high lead levels in the drinking water at Montgomery County public schools, officials say, but some parents worry that the problem might be more extensive.

"I think there's a real concern it's the pipes," said Cindy Kerr, president of the Montgomery County Council of PTAs. "But everyone knows how expensive that is."

Testing is not yet complete in all 192 schools in the county, and officials say there could be other problems with the water system.

"We won't really know until we're done with the testing," said Richard Hawes, the school system's director of facility management.

Hawes said initial tests indicate that the fixtures are the source of the lead. The school system is choosing replacement fixtures and hopes to begin replacing some of those used by students by the end of the summer.

The system began testing the water in March after reports of widespread lead contamination in the District.

The results of tests from 28 schools have been released so far, and all had at least one water source with impermissibly high levels of lead. The county has been testing every source of water in the schools, from fountains to janitors' sinks, used to fill mop buckets.

Samples have been taken from 122 schools, Hawes said, and are waiting to be analyzed by the Washington Suburban Sanitary Commission.

"There is just this huge backup trying to get the water tested," said Brian Porter, spokesman for Montgomery schools.

The county hopes to receive results on tests from all the schools by Aug. 15, Hawes said.

School officials say they are uncertain how much it will cost to fix the problem and do not yet know the final price tag for the gathering and analysis of water samples.

Last month, the county hired Science Applications International Corporation for $328,000 to collect the water samples, according to Hawes. "We feel we have to do this, and we're not really worried about the increased costs," he said.

Hawes said about 15 to 20 school employees were working on the project before SAIC took over.

But when the WSSC purchased new equipment about a month ago that allowed faster testing, the school system decided to increase its rate of sample gathering.

SAIC has increased the testing from two schools a day to an average of four, according to Ching Chen, a senior project manager for SAIC overseeing the water sample collection in Montgomery schools. The SAIC workers come in at 4:30 a.m., four days a week.

"We just couldn't handle it ourselves," Hawes said. "It was very cumbersome and hard."

Parents said they appreciate the county's thorough testing but expressed anger over the lack of communication with the school system.

"It's very frustrating," Kerr said. "We're aware that they are still doing the testing, but we haven't gotten any indication that there is any movement on how to fix the problem."

Some County Council members also expressed concern, saying replacement of the fixtures might not be a panacea.

"I think a healthy skepticism is appropriate," said council member Michael Knapp (D-Upcounty), who sits on the council's education committee. "I don't want people to think that because we've swapped out the fixtures, we've necessarily fixed everything."

Knapp says a regular monitoring program is needed to protect against future problems with the school system's water.

"I hope we've learned our lesson," Knapp said. "I hope we continue to be vigilant and keep testing."