Preventing Legionellosis has risen on the priority list of Building Owners and Managers due to heightened awareness and unfolding regulations in parts of the US. Taking proactive steps to ensure water system safety involves effective planning, development of/adherence to a water management plan, and specific testing for the organism. While it is estimated that there are over 50 species and 70 serogroups of Legionella, community-acquired Legionnaire’s Disease is dominated by Legionella pneumophila, serogroup 1. Therefore, the laboratory selected to support implementation of a Water Management plan should not only be CDC Elite, but should employ methods that are statistically effective at detecting Legionella pneumophila, serogroup 1 with a high degree of accuracy in both cooling towers and potable water systems.