The update was issued in a letter to the campus community. We have posted the complete letter below:
Dear campus community,
As you may know from our prior communications, we have been undergoing an extensive water-testing program across campus since becoming aware of an employee with Legionnaires’ disease. While the majority of our tests have shown safe or nondetectable levels of legionella, areas that tested positive have been under remediation (i.e., plumbing and water management changes to eliminate or mitigate Legionella). While most of the remediation has been completed, some projects require taking rooftop cooling towers out of service temporarily, which affects air conditioning in those buildings.
In the case of the Towers Residence Suites, we have decided to replace the rooftop cooling tower, which will require several more weeks before the building will be reoccupied. Today, we received preliminary test results for the rooftop cooling tower of the Student Center Building, which also showed signs of Legionella, though at lower levels than the rooftop cooling tower on the Towers Residence Suites. Ordinarily, we would treat this level chemically and monitor results, but we are taking every precaution to ensure safety and have decided to take the unit out of service for several days to perform a combination of chemical shock treatments and industrial cleaning. Unfortunately, this will compromise the air conditioning while the unit is out of service in some areas of the building, particularly the upper floors.
The Student Center will remain open for events, and we apologize for any inconvenience or discomfort. Temporary cooling will be installed on the second floor and in the food court, and other areas in the building have independent cooling. Permanent occupants of the building will be notified by their management regarding any adjustments in work scheduling based on building temperatures.
As you know, the safety of our university community and guests is always our top priority, and we continue to coordinate with the city and state health departments as we work to eliminate the risk of Legionella on our campus. In the meantime, the Michigan Department of Health and Human Service noted recently  that Michigan was experiencing an increase in Legionellosis across the state. We hope the learning we accumulate and share can help address this situation now and in the future.
Michael G. Wright
Vice President for Communications and Chief of Staff