COLLEGEVILLE -- A boil order has been lifted at St. John's University after tests of its water supply were returned as negative for E. coli.

The Minnesota Department of Health granted permission to immediately lift the order on Wednesday, according to an email from the university.

The directive was issued last week after E. coli bacteria were discovered in a building inside of the university's water distribution system. Chlorination and system flushing began immediately, according to SJU.

The source of the contamination has still not been identified. Chlorination of the campus water system will continue through Nov. 1.

St. John's University will begin fall classes on Monday, Aug. 26.