NSF International and ASHRAE have signed a memorandum of understanding (MOU) dedicated to protecting public health by establishing safe management practices for building water systems. These systems include cooling towers, air conditioning units for large buildings, hot tubs, large complex water systems (hotels, hospitals, cruise ships and institutions) and decorative fountains, which can be attributed to public health concerns such as Legionella. Under the terms of the MOU, NSF will provide its 70-plus years of water industry expertise and ASHRAE will leverage its building systems expertise to jointly develop NSF 444: Prevention of Injury and Disease Associated with Building Water Systems. This new standard will address concerns such as legionellosis, which according to the CDC is on the rise. The CDC estimates that between 8,000 and 18,000 people are hospitalized with Legionnaires’ disease in the US each year.