Sample Collection and Shipping Procedures for Legionella

  1. Personal safety and precautions should be observed during sampling. Avoid breathing aerosols that may be contaminated with Legionella bacteria. Avoid generating aerosols or water mists during sampling of the water system. If you have been fit tested, wear a respirator equipped with a HEPA cartridge, goggles, and nitrile gloves.
  2. Prepare or obtain sterile, screw-capped plastic bottles for sampling. Sodium thiosulfate is routinely added to the bottle as a preservative and halogen (chlorine)-neutralizing agent. A 1 liter water sample is recommended for potable water sampling and 250 ml for non-potable water sampling.
  3. For drinking or potable water such as drinking water fountains, faucets, and showers, collect both hot and cold samples if possible. Collect the “pre-flush or first draw” sample by draining the first 1000 ml of water from the faucets or flush drains into a bottle. Leave a one-inch air space on top of the water sample.
  4. When sampling faucet aerators and showerheads, swabs of faucet aerators and inside the faucet and shower heads should be taken. When sampling cooling towers, whirlpool spas or fountains, look for areas of biofilm and take a swab sample of the biofilm. We provide sterile swabs for this purpose.
  5. For non-drinking or non-potable samples from such sources as cooling towers, chillers, surface water in reservoirs, sprinklers, etc., collect 250 ml water from the bottom or side of the vessel or reservoir. If taking a cooling tower sample, also consider taking a sample in the pack column. Leave a one-inch space on top of the sample. Record any biocide used in water treatment when collecting non-drinking water. If the water treatment includes the use of chlorine, be sure you use bottles with the sodium thiosulfate preservative. If sampling whirlpool spas, consider taking a swab sample of any biofilm as well as a sample of the sand filter.
  6. Label sample number on the bottle and record on the sample data sheet. Use a distinctive number for each sample. Complete all sample information on a sample data sheet for your own record. Send a copy with the samples to the laboratory.  You can download a copy of the Chain of Custody form this website.
  7. Tightly cap the bottles. Make sure that water does not leak during shipping and transporting. Place the samples in insulated boxes or on freezer packs to protect specimens from extreme temperature fluctuations in the summer months. NEVER USE ICE OR DRY ICE. Stuff the box with packing material cushion, and seal the box securely for shipping. Send samples by overnight express carrier. Schedule sampling between Monday and Friday so that samples can be delivered to the laboratory no later than Saturday. Take holidays into consideration.