Exasperated Boston Public School parents are calling on the city to replace aging pipes that keep seeping unsafe lead levels into student drinking water.

“Last year, schools added new water apparatuses, yet they haven’t done the required work of changing the pipes,” said Kenny Jervis, a parent of a Boston Latin School student.

“I find it interesting Boston has the best water than almost any municipality in the country, yet we have 58,000 students who grow up not thinking the water is drinkable,” Jervis said.

The parents’ demands come a day after Schools Superintendent Tommy Chang announced that water fountains at six school buildings were turned off after the district found they tested positive for unsafe lead levels. Schools include the Patrick Lyndon K-8; Lee Academy; Josiah Quincy School; Boston Latin School; F. Lyman Winship Elementary; and Jeremiah E. Burke High/Dearborn STEM Academy.

The discovery was made after an independent engineering firm retested the drinking water in 30 school buildings with active water foundations as part of the district’s new policy.

“It seems systemic of an aging infrastructure of the city,” said Ronak Shah, a Lyndon parent. “I’m hoping for some good rational discussion about what next steps will be like. It can’t be solved with just a bunch of testing.”

Mayor Martin J. Walsh said the city is trying to “get to the bottom” of why the drinking water at public schools keeps testing positive for unsafe lead levels.

Chang said the district anticipated that some schools would test positive for unsafe lead levels after water foundations were dormant over the summer.

“Boston Public Schools is literally on the front lines of this issue,” Chang said. “We said we will not start the school year without testing. We know water had been stagnant. We anticipated there would be schools with elevated levels.”