Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content

Water System Maintenance

The key to preventing Legionnaires’ disease is to prevent Legionella colonization (growth) in water systems. This page offers information for routine maintenance of building and recreational water systems for the prevention of disease.

Building Owners and Managers

Guidelines for reducing the risk of Legionella growth and spread are available for those who maintain and manage building water systems, including systems for potable (water for drinking and showering), non-potable, and recreational water from ASHRAE®. ASHRAE is a not-for-profit organization that develops standards and guidelines for industries that design, manufacture, and maintain building systems.

CDC developed a toolkit to help building owners and managers better understand ASHRAE Standard 188 and how to develop a water management program to reduce the risk of Legionella growing and spreading in their building(s). The first step is determining if your building or certain devices in your building need a water management program. Use this quick yes/no worksheet to find out. If so, learn more about developing a Legionella water management program.


Operating Public Hot Tubs

Water Management Program book cover

Developing a Water Management Program to Reduce Legionella Growth and Spread in Buildings
This toolkit provides practical guidance on how to implement industry standards by identifying areas or devices in buildings where Legionella might grow or spread to people so that risk can be reduced through effective water management.

Low water volumes combined with high temperatures and heavy bather loads make public hot tub operation challenging. The result can be low disinfectant levels that allow the growth and spread of a variety of germs (e.g., Pseudomonas and Legionella) that can cause skin and respiratory Recreational Water Illnesses (RWIs). Operators that focus on hot tub maintenance and operation to ensure continuous, high water quality are the first line of defense in preventing the spread of RWIs.

The Model Aquatic Health Code (MAHC) is a voluntary guidance document based on science and best practices that can help local and state authorities and the aquatics sector make swimming and other water activities healthier and safer.

If you are involved in hot tub maintenance, you should

If cases of Legionnaires’ disease or Pontiac fever are linked to a hot tub, it is important to take samples for laboratory testing before disinfecting the hot tub. However, the hot tub should be turned off immediately to prevent more people from getting sick. CDC has a video that walks through the process of collecting water samples from hot tubs for environmental testing. Detailed instructions for disinfecting hot tubs are available on the fact sheet Disinfection of Hot Tubs Contaminated with Legionella [2 pages].

CDC’s Healthy Swimming and Recreational Water website has addition resources related to Pool and Hot Tub Operation.


Working with Legionella Consultants

If your building needs a Legionella water management program or remediation services, you may consider working with one or more Legionella consultants. Learn more about considerations when working with Legionella consultants.

 Top of Page