What is Legionella?

Since the 1976 outbreak of Legionnaires’ disease in Philadelphia, data continues to demonstrate how dangerous Legionella pneumophila bacteria can be to the general public.

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.


Water Management Programs

ASHRAE has published the first United States standard for Legionella. ANSI/ASHRAE Standard 188, Legionellosis: Risk Management for Building Water Systems provides minimum risk management requirements for new and existing buildings and the associated water systems and components.

ChemTreat Water Management Program offerings include:

  • ASHRAE 188-compliant Water Management Plans
  • New York State and New York City-compliant Water Management Plans
  • Legionella Sampling Services
  • Water Management Plan program training


Cooling Water Offerings

ChemTreat field engineers are experts in industrial cooling, with extensive experience in a variety of applications.

ChemTreat cooling water treatment programs offer:

To learn more about our cooling water treatment offerings, click here.


Potable Water Offerings

The Centers for Medicare and Medicaid Services (CMS) require healthcare facilities to reduce Legionella risk in healthcare facility water systems to prevent cases and outbreaks of Legionnaires’ Disease.

Medicare and Medicare/Medicaid-certified healthcare facilities are expected to have water management policies and procedures to reduce the risk of Legionella growth and spread.

CMS recognizes the ANSI/ASHRAE Standard 188 and its partner, the CDC Toolkit, as resources for developing water management programs.

ChemTreat partners benefit from our expertise in many areas of Legionella risk management, such as:

  • Water management program development, including training and education
  • Validation testing and reporting, including Legionella sampling services
  • Remediation and disinfection support