Return to site home page


9 Ways to Avoid Legionella

Implement a water management plan without ballooning your budget

By Matt R. Freije


Implement a water management plan without ballooning your budget.

Legionella virus

Are you taking Legionnaires’ disease seriously enough? The summer 2015 outbreak in New York City that killed 12 people and sickened over 100 more underscores the danger to your building occupants (and your reputation) if Legionella risk isn’t managed carefully.

Because Legionella is a building water problem, health officials agree that managing building water systems properly is the key to prevention. Since last summer’s outbreak, laws were established to require building operators in New York State to create water management plans by March 2016 that include cooling towers.

Take this opportunity to reduce your legal risk, protect your brand and show leadership in corporate responsibility by instituting a water management program informed by ANSI/ASHRAE 188-2015. This regulation-ready standard has broad support for its Legionella prevention approach and complies with Veterans Health Administration and World Health Organization guidelines.

However, ASHRAE 188 only provides a framework and basic requirements – the rest is up to you. Your decisions can impact the success and cost of your water management program for years downstream. Lay a solid foundation for success with these nine tips.

1) Understand Your Portfolio

Which properties should have water management plans (WMPs)? For a multi-building campus, should all the buildings be included or just some of them?

A WMP can cover all the buildings on one site, but not multiple sites. For example, only one WMP is needed for a property with multiple buildings managed by the same personnel even if the buildings are for different uses (e.g., healthcare and office). But three buildings in different locations – even if the buildings are similar in size and configuration and located within a few miles of each other – will require three WMPs, one for each site.

What about leased buildings? Deal with landlords and tenants as necessary to ensure control measures are implemented. You may need to ask (or require) tenants to maintain their plumbing fixtures per your WMP. Otherwise, those areas could not only present a risk to people in the tenant space but also affect Legionella growth in other parts of the plumbing system. If the tenant is responsible for maintaining a cooling tower that could affect people in its building as well as other buildings on the campus, ensure the tenant’s cooling tower maintenance complies with your WMP.

2) Include All At-Risk Water Systems

Standard 188 requires WMPs to account for cooling towers, whirlpool spas, ornamental fountains, water features, misters, air washers and humidifiers. For plumbing systems, however, the standard requires a WMP only if the building has any of the following:

■     A centralized hot water system
■     More than 10 stories
■     Housing designated for people over 65
■     Patients staying longer than 24 hours
■     An area housing or treating people who are immunocompromised or otherwise more susceptible than the general population to Legionella infections.

How you apply the first two factors – centralized hot water systems and the number of stories – is crucial to risk management.

All other factors being equal, a centralized domestic hot water system (for example, ground floor water heaters supplying hot water to faucets with recirculation back to the heaters) is typically more prone to Legionella growth than a system that supplies only cold water to faucets with tankless heaters underneath. But other non-centralized domestic hot water configurations – such as small tank-type water heaters for apartment units or sets of common-area restrooms – may actually be more prone to Legionella growth than a centralized system with recirculation.

It’s also not uncommon to find Legionella in samples collected from domestic cold water systems, especially during the summer when the water may not be all that cold.
Think carefully about the number of stories as well. Larger piping networks are generally more prone to Legionella growth than ones found in single-family homes or small office buildings, but Legionella testing data indicates that you’d be foolish to assume a building is free of Legionella because it has 7 stories instead of 11.

Consistency is key to making good decisions. If you have authority over several buildings and only some of them have an ASHRAE 188 risk factor, be consistent with control measures regardless of your decision about establishing a WMP.

Let’s say you have 20 buildings in your portfolio, 15 of which have either 10-plus stories or a centralized domestic hot water system, and 5 that don’t have any risk factors. If you establish a WMP for the 15 but not for the other 5, you should still implement control measures in the 5 that are consistent with the 15 for like-kind equipment. For example, if the WMPs for the 15 buildings outline control measures for cold water storage tanks, implement those same measures for cold water storage tanks in the other 5. If the WMP for the 15 buildings has flushing procedures for infrequently used faucets, make sure the other 5 buildings use the same. Otherwise, if a case of Legionnaires’ disease occurs, how will you explain why you implemented control measures in buildings 1-15 but not for the same equipment in buildings 16-20? Saying ASHRAE 188 did not require a WMP is not a good enough answer – your program must be defensible.

A smart approach might be to establish comprehensive WMPs for buildings with risk factors and then decide how to keep the other buildings consistent with that plan. For some facilities, it may make sense to establish a full WMP even if ASHRAE 188 does not require it. In others, you might create a simple list of maintenance measures without all the elements of a full-blown WMP such as team meetings and validation.

3) Define the Assessment Scope

A WMP should be established based on types of building water systems rather than on Legionella test results or the condition of equipment. This means that the objective of the assessment is not to assess risk to determine whether a WMP is needed; the point is simply to identify the types of water systems on the site, note key system components and construct diagrams showing how the systems flow to one another. Taking pictures can be helpful to the team but is optional. Testing water systems for Legionella can provide valuable information for validating the effectiveness of a WMP, but is not necessary for the assessment.

Your assessment also doesn’t need to report conditions conducive to Legionella growth or transmission. A comprehensive WMP will include control measures to correct any problems a surveyor would find. That is why the water management plan model provides better risk reduction than periodic expert assessments. Instead of getting a risk assessment report card once a year, the WMP leads the facilities personnel down a path of continuously uncovering and correcting potential problems.
Because the primary objective is to identify water systems rather than assess risk, it is actually more accurate to call it a site survey or water systems survey rather than an assessment.


4) Define a Specific Hazard

How your WMP defines water systems hazards will affect the complexity and validation of the WMP. There isn’t a right or wrong definition; just be aware of the impact of your decision. For instance, a very broad definition would be “all building-related hazards,” which includes indoor air as well as water. Narrowing the definition to just water-related hazards covers chemical and physical hazards as well as biological. You could reduce it further to waterborne pathogens or even just Legionella. The broader the definition, the more complex the WMP.

Legionella is an ideal target pathogen for building water management. It’s not the only organism that can cause disease in a building environment, but it’s the best pathogen on which to base water management procedures because it is the only one that has caused numerous cases of severe illness and death, is entirely environmental (meaning that it can’t be transmitted from person to person), is controlled primarily in building water rather than city water supplies, can be detected in water via reliable methods and has been studied extensively, resulting in an abundance of scientific data on which to base control measures.

Legionella management will affect a number of other pathogens, particularly ones that multiply in biofilms within a proximal temperature range, such as Mycobacteria avium (which causes tuberculosis-like symptoms in immunocompromised people) and Pseudomonas aeruginosa, which can cause several kinds of bacterial infections and is resistant to many antibiotics. In a sense, a comprehensive Legionella WMP will under-promise and over-deliver.

5) Develop Deliverable Specifications

To be consistent with ASHRAE 188, water management plans must include a few vital elements (see “What Belongs in a Water Management Plan?” below).
Keep the plan focused by simply listing what the facility will do to meet the requirements. Background and explanatory information belongs in training materials, not in the WMP. Those who have to implement the WMP will appreciate a format that makes it easy, without extra words to read.

6) Know Your Team

Deciding what your own personnel can take care of and when to bring in an outside expert is crucial for success.

The site survey does not require Legionella expertise. Someone at your facility who knows your water systems could do the survey quite well and probably in roughly the same time they’d spend accompanying a vendor around the facility. However, writing the WMP requires Legionella expertise and experience, especially for the hazard analysis, control measures and validation procedures.

In-house facility personnel, particularly at larger facilities, can and should handle the routine maintenance procedures outlined in the WMP, but outside help will be needed for Legionella testing, which involves writing specifications, collecting samples and laboratory testing, as well as water treatment and remediation.

Facilities that try to handle all aspects of WMP development themselves end up with inadequate control measures and spend more money than they would have hiring expertise where needed. Facilities that try to sidestep the development process by hiring it all out will overpay for their WMP and fall short of optimal risk reduction by undervaluing the importance of their involvement and ownership. Strike the right balance for your organization.

7) Choose the Right Control Measures

Control measures are the most important part of any Legionella water management plan. They must be thorough, specific, effective, evidence-based, defensible and doable without costing more than necessary.

If the WMP excludes important control measures or includes unnecessary ones, it will be inadequate for reducing risk, too expensive or both.

8) Validate the Plan

Validating the effectiveness of the WMP in controlling the hazard is second only to control measures in importance.

Legionella testing is discussed as a validation option in ASHRAE 188 but is not required. Testing water systems for Legionella can provide the most direct feedback on Legionella control, especially in plumbing systems and cooling towers, but only if it’s done well. Sampling specifications must outline the right locations, devices, water (hot vs. cold) and collection methods to produce data for decision making. Samples must be collected and recorded properly and tested by a competent laboratory. And the test results must be correctly interpreted and acted upon.

9) Ensure Good Execution

The football team with the best players and playbook won’t win unless its players can put their plan into action. Likewise, getting a good WMP is only the beginning. It must be well executed to be successful.

Implement your control measures. Educate employees. Verify implementation. Validate well. Respond appropriately to test results. Document thoroughly and efficiently. Hold team meetings no less than quarterly. Revise the plan based on verification and validation results and new scientific findings, technology, standards and regulations.
Like working out, it will be uncomfortable at first. Maybe even painful. But after a while you will get in a rhythm and find it quite manageable.

Your efforts will help you reduce your legal risk, avoid business losses and protect against brand damage. You may even save lives.

What Belongs in a Water Management Plan?

Make sure you account for these seven areas when developing your plans to reduce Legionella risk.

A list of water management plan team members. Teams typically consist of 10 or fewer facility employees who oversee the program and make decisions about it. Many others, including vendors, will be needed to implement the WMP.

A brief description of the building water systems with flow diagrams. Salient information must be included for all building water systems, not just ones requiring Legionella control measures. Simple line flow diagrams should show where water is received, processed and used.

Hazard analysis of the water systems. If you define the hazard as just Legionella, the analysis will note which water systems present a significant potential for Legionella growth and transmission and whether Legionella control measures can be effectively applied there.

Control measures. The team must come up with a specific list of control measures for each building water system. ASHRAE 188 offers a framework for the team to fill in, stating that procedures must be included for new construction, equipment siting, start-up and shutdown, inspections, maintenance, cleaning, disinfection, monitoring for factors like
temperatures and disinfectant levels, and water treatment.

The team must also write out steps for responding to Legionnaires’ disease if a case occurs despite the prevention efforts. Each control measure must be monitored to determine whether it is performed to a team-defined standard (called the “control limit”). If it isn’t, then corrective action must be implemented. The monitoring procedure, control limit and corrective action must be listed for each control measure.

Documentation procedures. You need to document all control measures and other water management activities. A number of methods will likely be needed, including logs, vendor reports and maintenance schedules.

Verification procedures. A designated verification person must review the documentation to ensure the WMP is being implemented.

Validation. The effectiveness of the WMP in controlling Legionella must be validated.

Matthew R. Freije has specialized in Legionella prevention since founding HC Info in 1995. He has taught seminars in five countries, served as an expert in more than 60 lawsuits and written two books, nine e-learning courses, and a web-based water management plan development and documentation tool.