Colilert Collection/Shipping Guidelines

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Sample: potable water collected in a sterile container; for chlorinated water use a container with sodium thiosulfate neutralizer.

  • Colilerts are processed Monday –Thursday during normal business hours and only until noon on Fridays.
  • Colilerts cannot be processed Saturday or the day prior to a holiday.

Method: qualitative colorimetric detection of E. coli and coliforms; this method can detect a single viable coliform of E. coli in the presence of up to 20,0000 CFU/mL of heterotrophic bacteria.

Collection: Sterile screw-top containers for water collection are available free of charge from U.S. Micro-Solutions, call 724-853-4047.

Potable Water -Distribution System without attachments:

  1. Select a tap that is supplying water from a service pipe directly connected with the main, and is not, for example, served from a cistern or storage tank.
  2. Open tap fully and let water run for 2 minutes or for a time sufficient to permit clearing of the service line.
  3. Reduce water flow to permit filling the sample container without splashing. Collect 100 mL of water.
  4. Label the sample container with the sample number.
  5. Maintain sample at 2-8°C (refrigerator) after collection.
    • Samples must be received within 24 hours of collection.

Potable Water -Well fitted with a hand pump:

  1. Pump water for about 5-10 minutes or until water temperature has stabilized then fill the sample container without splashing.Collect 100 mL of water.
  2. If no pumping machinery is available, collect a sample directly from the well by means of a sterilized bottle fitted with a weight at the base. Take care to avoid contaminating samples.Collect 100 ml of water.
  3. Label the sample container with the sample number.
  4. Maintain sample at 2-8°C (refrigerator) after collection.
    • Samples must be received within 24 hours of collection.

Shipping:

  1. Clearly label each sample with a Sample Number and complete the Chain of Custody (COC).
  2. Place sample in a Ziploc bag and then in a box with an insulated foam liner and ice pack.
  3. Insert the completed COC form into a plastic sleeve or Ziploc bag and place in box.
  4. Ship samples Monday through Thursday (noon) for receipt within 24 hours of collection.
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