How To Take A Water Bacteria Sample


  • Sample(s) must be submitted in a sterile 100 ML EPA Approved plastic bottle. (Fill bottle so the water is at the 100 ml mark. (DO NOT UNDER/OVER FILL.)
  • Sample(s) MUST ARRIVE AT OUR LAB within 24 HRS. of collection. We accept samples between 9 AM and 4:00 PM.Mon.-Thurs. & 9 AM-12 PM (Noon) Friday (WILL NOT ACCEPT SAMPLES ONE DAY PRIOR TO A HOLIDAY).
  • SHIP SAMPLES(S) (WITH AN ICE PACK – WATER BASED). DO NOT FREEZE. Coliform organisms may die if these instructions are not followed, and may not be accurate or valid. 



Selecting A Tap:

  • For irrigation water, sample at the point where it contacts produce (Run 20 Min.).
  • DO NOT sample from hoses or drinking fountains.
  • Avoid taps with leaks at faucet or stem.
  • Avoid taps with SWIVEL JOINTS.
  • The nearest tap to the well is preferred if you want to check the well for bacteria.
  • Bathroom faucet is better than a swivel kitchen faucet, if you are testing the water you are drinking, (use cold water faucet). 

Sterilize The Faucet:

  • Remove aeration screen from inside of cold water faucet.
  • Take a quart plastic bag. Fill 3/4 full with water and add 1 ounce of chlorine/regular bleach into bag.Please check the active ingredient statement on the label. It should be Sodium Hypochlorite, 5.25% or greater. Also, be sure that somewhere on the bottle it states that it can be used for sanitizing and disinfecting.
  • Immerse the faucet inside the bag. Pull up on the bag until the open end of the faucet is against the bottom of the bag. Hold like this for 60 seconds. This will sanitize the opening and inside the faucet.
  • Remove the bag and empty into drain. DO NOT touch the faucet opening.

Flush The Tap:

  • Turn on COLD WATER  faucet fully open as possible.
  • Let run 3 minutes minimum, up to 6 minutes until constant temperature is reached

Taking The Sample:

  • Reduce water flow to pencil width. (Ready for plastic bottle).
  • Remove the plastic seal (discard) and the cap from bottle. DO NOT touch inside of cap or mouth of bottle.
  • Continue to hold cap in fingers. Do Not lay on counter, etc.
  • DO NOT rinse bottle out. Leave the white powder residue inside.
  • Fill bottle to the line marked 100 ml. DO NOT under/over fill bottle.
  • Immediately recap bottle tightly, and keep the sample cool. (about 35 to 47 deg. F.)

Submitting Samples:

  • Label your bottle with your name and a sample description.
  • Complete the Sample Information Form. (Print name, address, test desired, etc.)
  • Return the water sample(s) with an ice pack.  This must be a water-based ice pack (frozen water is best to lower temperature to preserve the bacteria sample) Do Not use the gel filled reusable ice packs.  DO NOT FREEZE THE SAMPLE BEFORE SUBMITTING.  Include the Sample Information Form, and payment to “HOLMES LABORATORY, INC.” in a cardboard box for protection during shipping.