Boston school officials plan to notify parents at four schools that their children may have drunk water tainted with lead from drinking fountains that were mistakenly turned on before water testing was complete.
The fountains were active for as little as several hours to as long as three weeks.
Boston Public Schools recently launched a $300,000 project to repair and upgrade plumbing so that fountain water could be restored at six buildings that had been using bottled water.
The facilities were selected for the pilot program because prior tests indicated lead levels that were below state and federal standards, school officials said.
However, testing conducted in recent months found elevated lead levels in at least one fountain at four of the six schools. Lead contamination was also found at a fifth school, but officials don't believe anyone drank from the fountains.
School officials had previously told the Globe that none of the new fountains had been turned on since being installed. But they had learned in recent days that the fountains had been mistakenly activated, they said Wednesday.
Officials blamed a lack of communication between employees of the school district's facilities department and a third-party contractor.
The fountains are now shut off in all six schools. Bottled water is being provided there instead, officials said.
The four schools where children may have drunk water with high lead levels are Mather Elementary School, Lee K-8 School, Curley K-8 School, and Another Course to College.
"The safety and well-being of our students, staff, and community members is always a primary concern and all incidents will be investigated to ensure that such an occurrence never happens again," said a statement from Boston Public Schools.
"BPS is communicating with families at the schools about these circumstances and their options if they are concerned about potential exposure to lead in drinking water," the statement added.
School officials said automated phone calls were to be made to families at the affected schools Thursday afternoon and that letters would also be mailed home.
In the meantime, school officials continue to probe why water from the new fountains has high lead levels, a process that may cause the project to run over budget.
Officials had hoped the new fountains would produce long-term savings by allowing the schools to drop their costly reliance on bottled water.
Most Boston schools use bottled water because of past lead concerns. The city expects to spend $415,000 this school year alone to provide bottled water.
Four other schools that were still using tap water were recently found to have high lead levels in fountains. The affected fountains were shut off and replaced with bottled water.
Children are particularly vulnerable when it comes to lead. Exposure has been linked to IQ deficits, shortened attention spans, behavioral problems, hearing damage, stunted growth, and lowered birth weight.
The school department provided the following details on the four schools where the fountain restoration project has gone awry:
■ Mather Elementary School, Dorchester — School officials believe the fountains were in use from Nov. 23 through Dec. 14. Subsequent testing found high lead levels (above the state's standard of 15 parts per billion) in seven of the school's nine fountains. School officials also sent a letter to families about the issue in February.
■ Lee K-8 School, Dorchester — Officials believe the fountains were turned on and accessible for about five days. Testing found high lead levels in one of the school's seven fountains.
■ Curley K-8 School, Jamaica Plain — The fountains were turned on and accessible for between 24 and 48 hours, officials believe. Testing found high lead levels in eight of the school's 12 fountains.
■ Another Course to College, Brighton — The fountains are believed to have been turned on and accessible for 12 to 24 hours. Testing found high lead levels in one of the school's six fountains.
Officials said they were also contacting parents at Trotter Innovation School in Dorchester and Boston Green Academy in Brighton, the two other schools in the fountain restoration project.
At Trotter, high lead levels were found, but officials believe no one drank from the fountains. At Boston Green Academy all six fountains tested had lead levels below the state's threshold.
The school department has posted a fact sheet online about lead in drinking water, and officials said the health services staff are available to answer questions.