Sample documentation is available for this feature part–be sure to reference this resource as you prepare your documentation.

Legionnaires’ disease is the leading cause of reported waterborne disease outbreaks, hospitalizations and deaths in the US between 2015 and 2020. It is caused by Legionella bacteria, a pathogen that can quickly grow inside water pipes, spas and cooling towers where water circulates between 77 and 113°F. While large buildings are at higher risk of Legionella growth because of the size and complexity of their piping system, all buildings should manage the risk as outbreaks have been reported in smaller building typologies such as private residences. The management strategies, however, should be proportional to the risk; small buildings may not need to hire an expert to develop a plan, and instead use simple measures to assess and update risk on a regular basis. With these considerations in mind, here is a how-to guide to implement a water management plan in smaller properties or subsets of larger buildings that meets the requirements of the WELL feature W03.2: Implement a Legionella Management Plan.

With these considerations in mind, here is a how-to guide to implement a water management plan in smaller properties or subsets of larger buildings that meets the requirements of the WELL feature W03.2: Implement a Legionella Management Plan.

1. Scope the plan preparation

• W03.2 Implement Legionella Management Plan requires that a water management plan is developed and implemented at the project.  If your project only is of small scale or a tenant space within a building, only have taps for kitchen, janitorial use, drinking water and restrooms with only a few showers, is not a hospital, nursing home, hotel or a multifamily residential project, and do not control water assets such as cooling towers, heated water pools or anything where warm water recirculates, you can reduce the scope of your water management plan for Legionella by following the guidance below. Note that if a building-wide water management plan is needed (because of the size or complexity of the project), it is advisable to hire a specialist to develop the plan. If you manage a space within a large building, it is possible that your landlord already has a compliant plan in place. If this is the case, you can use the building’s water management plan to support your WELL submission.
• For spaces with very simple plumbing set-ups and minimal hot water fixtures as described above, filling the requirements for this feature should take an on-site visit and approximately 1-2 hours of work.
• If you manage a tenant space within a building, work with your landlord and/or building manager to get information on systems that serve your project and any systems that occupants may come in contact with on their way in and out of the project (e.g., a lobby fountain). If they are uncooperative or do not have enough information, document your attempts to approach them and disclose any information provided.  

The steps below provide suggestions on what to consider when developing a water management plan that meets the WELL feature requirements for projects that are not hiring a professional to develop a full-fledged building-wide plan. 

2. Determine roles

Address requirement (b)(1): Determination of roles for Legionella management in the building, distinguishing those under project control from those that may be the responsibility of building management or other parties.

• The water management plan should document a list of the relevant roles for people in charge of assessing and managing Legionella risk in your location. This list should include:
  • The person who assessed the project’s risk factors associated with Legionella.
  • The plan preparer (whether developing a basic or full-fledged plan)
  • The plan executor or maintainer, usually an office or facilities staff member
  • If the space is part of a larger building, the role of the personnel managing the building operations

3. Make an asset inventory

Address the first part of requirement (b)(2): Water system inventory within the project boundary.  

Count and document the location of any sources of aerosolized water in your space, including hot water faucets and showerheads. Also include any cooling towers, spas, misters, fountains and other devices where lukewarm or hot water may recirculate. An unheated pool without sprayers or misters does not need to be considered. 

Include the inventory and their locations within the water management plan.

4. Make a process flow diagram of the relevant project water systems

Address the second part of requirement (b)(2): Process flow diagrams of systems within the project boundary.

Process flow diagrams are simple representations of the main stages in which water is transformed (e.g., heated), conveyed and / or delivered. In buildings, a process flow diagram for hot water includes depictions of main pipes, valves, mixing points, pumps, risers, boiler/heaters and points of entry and delivery of water.

These diagrams should include all hot water pipes and aerosolizing fixtures such as faucets and showers. An example of a common case is shown below:

If you are not familiar with the plumbing and cannot find the plumbing diagrams for your space or building, inquire with the building manager or someone knowledgeable of the building. Many problems in water quality management begin by not knowing how the plumbing is set up.

5. Assess Risk

Address requirement (b)(3): Hazard analysis of water assets within the project boundary. If the project does not operate the building hot water supply system (e.g., boilers, heaters, pumps or hot water risers), then an explanation of the building-wide Legionella management policies (if any) and how they influence risk is included.

The water management plan should document the following:

• If the project area is within a larger building, information about the building-wide water management plan (e.g., whether or not it exists, explanation as to whether it covers the water fixtures in your tenant space, the building POC, etc.).
  • Ask the building management whether a building-wide water management plan has been implemented or not. A managed building poses less risk than a building that does not manage its water quality. Describe in your plan your actions to engage landlords and/or building managers and whether they are cooperative in your risk assessment process.
  • If a building-wide water management plan exists, determine whether it addresses the water fixtures within your space (which may be the case if you have not added or modified internal plumbing as part of your construction scope). The project team will need to augment the plan to include any relevant fixtures within the WELL project boundary that are not currently covered by the building plan.
• Include a list of any “dead legs” in your hot water line. Dead legs are pieces of piping through which water cannot flow, usually installed for future connections. They are a known risk factor because they provide a place for water to stagnate and become a haven for microbial growth. To assess your space for dead legs, look for them under the faucets in bathrooms and kitchens that provide hot or warm water. Take photos if possible and add them to your risk assessment.

6. Establish protocols for monitoring

Address requirement (b)(4): A list of monitoring actions for relevant variables (e.g., temperature or residual chlorine), performance limits associated with these variables, and corrective actions when variables exceed such limits.

Here is an example of a monitoring action:

A policy to record the hot water temperature and time it takes water to get hot on a periodic basis (e.g., quarterly or every six months). 

The policy can specify that this should be completed for one of every five faucets or showerheads, using the diagram from (b)(2) to identify these points. With a thermometer and a timer at hand, a designated team member can perform the following:

• Wait 10 minutes since its last use.
• Set the tap at its hottest setting, start the water flow and the timer.
• Keep measuring the temperature until it begins to stabilize (i.e., stops getting hotter). Record the stable hot temperature as well as how long it took to stabilize.
• If the water takes more than a minute to reach its hottest setting, check with a plumber and/or the building manager about the cause of the delay. 
• Write down the hottest water temperature delivered at the faucet. 
  • The hot water temperature in a building should run at the temperature specified by the designer of the system. (Typically this will be approximately 120-130°F. For scalding protection, showers may deliver hot water at 110-120°F and hand washing taps at 120°F.) If the hottest water at the tap is significantly below these temperatures, the policy may indicate to check with a plumber and / or the building manager to investigate and remediate low temperatures at the hot water tap.
  • In locations where hot water is mixed with cold water, the project team can utilize a clamp thermometer and measure the temperature of the hot water pipe. Note that mixing before the point of use (unless the water is at least 120°F) increases the risk for Legionella. The farther from the point of use mixing occurs, the higher the risk.

Address requirement (b)(5): A list of critical control points (locations where actions to maintain relevant variables listed in (4) within performance limits are applied) within the project boundary.

• Control points are the locations where actions need to be taken if the control variables (i.e., temperatures and time to hot water) fall outside the desired range. Examples of control points that may need to be checked include: 
  • The boiler or water heater, to ensure that it is delivering water at the specified temperature (e.g.,  130-140°F)
  • Hot water pipe insulation, and/or 
  • Hot/cold mixing valves
• Tenants within larger buildings may not be able to manage all the control points in contact with the water being provided to the project. If this is the case, document this in the management plan and describe the person who is responsible for the building control points (e.g., the building manager or building operations’ specialist).

Address requirement (b)(6): Verification and validation procedures for evaluating the suitability and proper implementation of the management plan. A Legionella sampling schedule is included if projects have operational control over cooling towers and spas.

• The water management plan should include documentation stating a commitment to perform Legionella testing in the event that either: 
  • There is any substantial evidence of Legionnaires’ disease cases in building occupants, and/or 
  • The hot water temperature cannot be managed. 
• Note that cooling towers and spas require Legionella testing, and maintenance of those fixtures should be addressed within a full-fledged water management plan developed and implemented by a specialist.

7. Provide a template for ongoing management

Address requirement (b)(7): Protocols for documenting results of monitoring activities and corrective actions. If sampling for Legionella is planned, results are included

The water management plan should provide a template of measurements and log of facility management team activities and any plumbers’ visits and tests. The template should also outline who is in charge of this task as stated in (b)(1) above. 

To maintain your WELL achievement milestone, this feature requires that proof of ongoing management be submitted annually. Ongoing management may be as basic as repeating the temperature tests, depending on your water management plan. As a reminder, the plan should include a recommendation to follow-up on any results that require further inspection. For example, there may be a recommendation to talk to a plumber or a building manager if temperature tests reveal that the tested water is taking unusually long to get hot.

Additional resources

From submission to success: Strategic approaches for meeting feature requirements and avoiding common pitfalls