The Newark school system’s problem with lead in its water is more pervasive than authorities first disclosed when they shut down fountains and kitchen faucets last week after finding unsafe levels at 30 buildings in the district.

Elevated levels of lead were detected in Newark schools in the past, but were not made public — although authorities took steps to fix the problem by replacing fixtures and pipes and installing filters, the district said yesterday.

But no details were provided on how widespread the problem was; how many schools were found with high lead levels in their water; and what levels were detected, according to a two-page statement released by Newark public schools.

The disclosure is likely to heighten concerns about the elevated levels of lead recently found in Newark schools, and raise more questions about how seriously school officials dealt with the issue now and then.

Lead exposure has emerged as a growing public-health issue in the state as national attention has focused on a far more extensive problem with the contaminant in the drinking water in Flint, MI.

In New Jersey, so many children are suffering from lead poisoning that the Legislature yesterday gave final approval to a bill that would funnel $10 million to reduce childhood exposure to lead-based paint in houses. Gov. Chris Christie conditionally vetoed a previous version of the bill earlier this year.

[related]In Newark, where 5.7 percent of kids under six who were tested in 2014 had elevated levels of lead in their blood, the situation in the schools escalated to a barrage of accusations and criticisms from both the teachers union and school officials.

Newark school official accused the Newark Teachers Union of mischaracterizing an August 2014 memo reported on by NJ Spotlight. The memo spelled out a protocol for dealing with potential lead problems. It recommended following a procedure, initiated in 2004, of placing filters in fountains and kitchen sinks, flushing fixtures, and regularly replacing of filters.

John Abeigon, president and director of the Newark Teachers Union, released pictures of 10 schools where high lead levels were not detected that purportedly showed expiration dates from 2009 to 2015 on filters installed on water fixtures. He called for federal intervention and investigation into “this ongoing health crisis.’’

Chris Cerf, Newark’s state-appointed superintendent of schools, said the union, rather than helping address elevated levels of lead in drinking water, “has chosen to politicize the issue by spreading misinformation and allegations.’’

During the most recent round of testing of Newark schools — done in December –approximately 590 of 650 samples collected came back negative, according to Cerf. He said the district has launched an in-depth review of past data, protocols, and implementations.

“This review will help us better understand to what extent protocols were followed, and to specifically identify what has been done in each school to mitigate elevated lead levels in schools previously,’’ Cerf said in a statement to NJ Spotlight.

Both the district and the state Department of Environmental Protection expect to have a full set of results, and more specific remedial actions, available to the public this week.

Meanwhile, the DEP has developed a water-testing regimen to include all 67 school locations in the district with initial sampling to take place in the 30 school buildings where high levels of lead were detected.

In a separate three-page statement put out by NPS, the district said it decided to make public the latest sampling results because Cerf wanted to reach out to local, state, and federal authorities for additional expertise and support, rather than follow past protocols.