The Environmental Protection Agency has found high levels of PCBs in another school it tested this month during spot checks for the toxic substance in the city's schools.

Samples taken from five classrooms inside PS13 and Achievement First East New York Charter School, which share the same building in Brooklyn, were well above agency standards.

The toxic chemicals were found around the ballasts inside old fluorescent lights. The EPA has advised school districts to replace older lighting fixtures because they can contain PCBs, which were banned in the late 1970s. This is the fourth city public school to be found with PCBs in its lighting fixtures this year.

"At PS 13, which also houses the Achievement First East New York Charter School, all seven fixtures from which EPA drew samples, DOE took corrective action during the same weekend as the EPA inspection by replacing ballasts or fixtures as necessary," the Department of Education said in a statement. "EPA inspected 42 fixtures.  EPA indicates there is no immediate health risk for students and staff at these buildings."

In December, Deputy Chancellor Kathleen Grimm sent the EPA a letter in which the city estimated that at least 772 school buildings may have older lighting fixtures with PCBs. The city said the total number of fixtures with PCB ballasts could be "as many as 564,000."  The city has said the costs of replacing all the lights would be too high but that it's still working on a plan to inspect the schools, and that lights or ballasts are changed whenever PCBs are found.

Meanwhile, the EPA is conducting its own spot checks. It found PCBs earlier this month at two other schools on Staten Island (PS 53) and in Brooklyn (PS 11). The city also found PCBs at PS 36 on Staten Island after a teacher contacted the Department of Education about a leaking light fixture.