Proper Testing Procedures for Legionella

What are proper testing procedures for Legionella in water supplies? There are several variables that need to be considered such as proper location, tools needed, documentation and chain of custody. Need help with testing Legionella? Call the water professionals who have been working with water for nearly 90 years at or 888-416-8626. We can do the testing for you or assist.

Sample Locations:

  • Hot water fixtures close to the riser/in middle of the system/farthest fixture away from the riser.
  • Heating systems
  • Ice Machines
  • Problem areas such as locations where patients/tenants with possible immune deficiencies reside.

Tools needed:

  • Thermometer
  • Phone/stopwatch for flush time
  • Paperwork
  • Permanent Marker
  • Sample Bottle

Formal Legionella testing rules vary from state to state but they are all similar.

These steps should be consistent in most cases.

  1. Identify your testing locations.
  2. Work with your water management team to find key areas where you would like to test for Legionella.
  3. Make sure that these locations are clearly defined. With either room numbers or clear indicators.
  4. Fill out your chain of custody form. This form generally includes:
    • Name
    • Company Name and address taking the sample
    • Test site – address or business
    • Where you want the test results sent
    • Testing location – Onsite location where you are pulling your sample
    • Water use – waste water, drinking water, hot tub/pool
    • Time test was taken
    • Water temperature

Testing your water:

  • When you arrive at your test site, write your sample number and information on the bottle (In some cases matching stickers will be provided for your bottle and COC form).
  • Remove any filtration from the sample location if needed.
  • Turn your water source on slowly till it is fully open.
  • Let the water flush continuously for around 2 minutes.
  • Check temperature of the water continuously until it stabilizes.
  • Reduce flow to a slow but constant stream.
  • If applicable record the water temperature.
  • Take your water sample. Most testing bottles will have an indicator line for quantity.
  • Record the time in which the sample was taken
  • Package up the sample and COC form in the shipping box.
  • Ship same day or if you are close to your testing location take the sample to the lab same day.

Legionella / Pathogen Testing and Water Management Consulting

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Contact Legionella Control Systems for CDC Legionella risk assessment and Legionella testing.