Controlling Industrial Water Systems Legionella
By Reid Hutchison

Understand the New Building Water Management Standard: ASHRAE 514

Controlling Industrial Water Systems Legionella ASHRAE/NSF 514UPDATE: ASHRAE Standard 514 was updated in 2023, now known as ASNI/ASHRAE 514, and includes other microbial, physical, and chemical hazards. Contact an HOH rep for more information on the updated standards.

Most facility managers are already familiar with ASHRAE Standard 188, which established minimum risk management requirements for building water systems, with a particular focus on Legionella prevention. In 2019, ASHRAE began development of a new standard: ASHRAE 514. The guidelines in Standard 514 will extend beyond a narrow focus on Legionella to prescribe a comprehensive set of water safety practices for building systems.

Controlling Legionella in Building Water Systems

According to the CDC, the rate of reported cases of Legionnaire’s disease has risen over the past 19 years, increasing four and a half times since 2000. Data captured through November 3, 2018, indicates 7,104 cases that year.

Legionella prevention, especially in high-risk environments like healthcare facilities, is a constant challenge for facility managers.

The bacterium known as Legionella can cause one of two dangerous conditions:

  • Legionnaire’s disease, a severe form of pneumonia
  • Pontiac fever, a milder illness resembling the flu

These two diseases are sometimes referred to collectively as legionellosis. Legionnaire’s disease, if left untreated, can be fatal.

“Our customers are definitely concerned about Legionella,” says Reid Hutchison, Director of Operations at HOH Water Technology, Inc.

“The bacteria itself is an issue. It’s stubborn and takes some vigilance to control. But then there’s also the compliance side, which brings its own concerns. Diving in and dealing with it all head-on can be daunting. We know because there are still a lot of facilities that are avoiding the issue. Unfortunately, it’s not going away.”

The guesswork and hassle, and ultimately the risk, surrounding Legionella control are the main targets of the HOH water safety program, SafePath 188. But Legionella is not the only safety concern.

ASHRAE 514

Before 514, there was NSF Standard 444, which was developed to be a broad standard addressing several waterborne pathogens and was meant to help prevent the injuries and diseases they cause in humans.

Many of the same conditions that encourage Legionella growth also allow the growth of pathogens such as:

  • Pseudomonas
  • Acinetobacter
  • Burkholderia
  • Nontuberculous mycobacteria (NTM)

According to 2018-2019 ASHRAE President Sheila J. Hayter, P.E.:

“Standard 514 will go further to address building water quality, the importance of managing safe, quality building water systems and prevention strategies.”

It’s important for building managers to stay aware of new standards and updates to existing standards. But this can be a moving target. Many ASHRAE standards are updated every few years. Some standards are on continuous maintenance and are continuously updated through addenda.

Working with a professional water treater, developing a water safety team, and a water management plan are all critical steps to protect your facility and the people inside. The CDC recommends following this outline for developing a Legionella Water Management Program:

  1. Establish a water management program team 
  2. Describe the building water systems using flow diagrams and a written description
  3. Identify areas where Legionella could grow and spread
  4. Decide where you need to apply control measures and how to monitor them
  5. Establish ways to intervene when control limits are not met
  6. Make sure the program is running as designed and is effective
  7. Document and communicate all activities

Water safety is a big job, and it’s just one part of your responsibilities as a facilities manager. If you’d like help with Legionella risk assessment, contact the HOH team. We’ll look for ways to improve your water management program and help keep you compliant with safety standards.

Water Management