Portland Public Schools chief operating officer Tony Magliano and senior environmental manager Andy Fridley have been placed on paid administrative leave, pending the outcome of an investigation of elevated lead levels in drinking water at dozens of schools.

Superintendent Carole Smith and the School Board announced the decision late Thursday evening.

"Mistakes were made, and they were unacceptable," said Smith. "It was critically their department."

This spring, two school buildings—Creston and Rose City Park—tested positive for elevated lead levels, but PPS waited nearly two months to notify parents. At Creston, the water wasn't shut off at contaminated sinks and fountains for eight days.

On Tuesday, WW broke the news that the district had not disclosed to parents or school officials the results of tests that found elevated levels of lead in the water at 47 PPS buildings between 2010 and 2012. New counts show there were more than 50 buildings with elevated lead levels since 2003.

School Board Chairman Tom Koehler announced that an outside investigation is expected to take 30 days. The board selected the Portland law firm Stoll Berne to conduct the probe.

An email obtained Wednesday by WW showed that Magliano's claim that he was previously unaware of test results from 2010 to 2012 may have been less than forthright.