Legionella Control and Management

Since the 1976 outbreak of Legionnaires’ disease in Philadelphia, data continues to demonstrate how dangerous Legionella pneumophila bacteria can be to the general public. Recent events involving cooling towers have even been highlighted in national news reports.

Maintaining clean cooling systems, proper mechanical operation, and chemical programs within design limits are all important aspects of services ClearWater offers. We remain diligent in our efforts and provide our customers with timely information.

Legionella Information

The Centers for Disease Control and Prevention (CDC) Morbidity and Mortality Weekly Report (MMWR) from June 2016 summarized that from 2000 to 2014, the rate of reported cases of legionellosis (Legionnaires’ disease and the milder, influenza-like illness Pontiac fever) increased 286%, from 0.42 to 1.62 cases per 100,000 persons in the United States. The CDC considers Legionnaires’ disease to be underdiagnosed.

Sources of Legionella Bacteria

Legionella bacteria are found in both natural and man-made water systems. Legionella have been grown between 77 and 113°F (25 and 45°C) under laboratory conditions, with optimal growth between 86 and 108°F (30 and 42°C).

Guidelines for Legionella Control

ANSI/ASHRAE Standard 188-2015, Legionellosis: Risk Management for Building Water Systems became the first United States Standard to address Legionella. It provides a framework to develop a water management plan to minimize risk associated with illness. Other guidelines include: ASHRAE Guideline 12-2000, Minimizing the Risk of Legionellosis Associated with Building Water Systems; OSHA 1998 guidance, “OSHA Technical Manual, Legionnaires’ Disease”; and Cooling Technology Institute (CTI), WTB-148, Legionellosis Guideline: Best Practices for Control of Legionella.

Since the publication of the standard, New York City and State have enacted regulations to control Legionella in cooling towers and healthcare facilities. In June 2017, Centers for Medicare and Medicaid Services (CMS) published a directive that requires facilities to “develop policies and procedures that inhibit microbial growth in building water systems that reduce the risk of growth and spread of Legionella…”

In addition, the CDC has updated their Practical Guide to Implementing Industry Standards.

Let ClearWater helps you develop a Water Management Program.