Legionella Risk Assessment Form

Facility Characteristics
Indicate the type of facility (select all that apply):


Total number of rooms that can be occupied overnight (e.g., patient rooms, hotel rooms):

Does occupancy vary throughout the year?

Seasons with lowest occupancy (check all that apply):

Are any occupant rooms taken out of service during specific parts of the year, e.g., low season?

Which rooms?

Average length of stay for occupants:

Does the facility have emergency water systems (e.g., fire sprinklers, safety showers, eye wash stations)?

Are these systems regularly tested (i.e., sprinkler head flow tests)?

How often?

Date of last test

Does the facility have centralized humidification (e.g., on air-handling units) or any room humidifiers?

Describe their location and operation:

Has this facility been associated with a previous legionellosis cluster or outbreak?

Please describe the number of cases, dates, source if found, and any interventions (immediate and long-term) to prevent recurrence:

Does the facility have a water safety plan or Legionella prevention program?

Describe the plan briefly here (does it include clinical disease surveillance and/or environmental Legionella surveillance?) and obtain a written copy of the program policy:

Does the facility ever test for Legionella in water samples?

Obtain copies of results.

Water Supply Source
What is the source of the water used by the facility?

Name of supplier

How is the municipal water disinfected?


Has treatment of municipal water changed in the past year?


How is the well water disinfected?


Is the water filtered onsite?

SSpecify the other source of water

Have there been any pressure drops, boil water advisories, or water disruptions (e.g., water main break) to the facility in the past 6 months?

Describe what happened and which buildings or parts of buildings were affected:

Does the facility monitor incoming water parameters (e.g., residual disinfectant, temperature, pH)?

Obtain copies of the logs

What is the range of disinfectant residual, temperature, and pH entering the facility?

Premise Plumbing System

Are cisterns and/or water storage holding tanks used to store potable water before it’s heated?

Is there a recirculation system (a system in which water flows continuously through the piping to ensure constant hot water to
all endpoints) for the hot water?

Describe where it runs and delivery/return temperatures if they are measured:

Are thermostatic mixing valves used?

Describe where they are located (ideally, mixing valves are close to the point of use):

What is the maximum hot water temperature at the point of delivery permitted by state / local regulations?

Are hot water temperatures ever measured by the facility at the points of use?

Obtain copies of the temperature logs.

What is the lowest documented hot water temperature measured at any point within the facility?

Are the potable water disinfectant levels (e.g., chlorine) ever measured by the facility at the points of use?

Obtain copies of the logs.

How often are they measured?

List the range of disinfectant residuals.

Does the facility have a supplemental disinfection system for long term control of Legionella or other microorganisms?

Obtain SOPs for routine use and maintenance as well as maintenance logs and records of disinfection levels.

Describe any maintenance (either routine or emergency) carried out on the potable water system in the past year.


Additional Recommendations

Epidemiologist Name & Signature
Environmental Health Specialist Name & Signature
Public Health Offical Name & Signature
Person(s) interviewed during assessment

Name & Job Title

Please note that this checklist is a hypothetical example and provides basic information only. It is not intended to take the place of, among other things, workplace, health and safety advice; medical advice, diagnosis, or treatment; or other applicable laws. You should also seek your own professional advice to determine if the use of such checklist is permissible in your workplace or jurisdiction.