Bacteria Sampling Instructions

  1. Get a sterile sampling bottle:
    The sample bottle is sterile and will stay that way until opened.  Be careful not to touch inside the cap or bottle with anything but the water being sampled.  Do not rinse out the bottle and do not open it until you are ready to fill it.  It is normal for there to be a small amount of liquid or white crystals in the bottle or for the bottle to be slightly discolored.

  2. Choose a sampling point:
    The cold water faucet you choose should be clean and free of leaks or drips, should face downwards, and should be at least 18” above the ground. Do not use a "swing faucet" (like most kitchen faucets). Remove any attachments such as hoses or faucet aerators.  Spraying the tap with a 10% solution of bleach can help prevent false results due to contamination from the tap itself.

  3. Check for chlorine:
    1. Non chlorinated Systems: Unless your water system is normally chlorinated be certain that all traces of chlorine are gone before you sample. Use a chlorine test kit, such as a pool test kit. Chlorine testing materials are also available from the lab at a nominal charge. If chlorine remains in the water, the test results will be invalid. The sample will be screened at the laboratory and rejected if chlorine is present. It is highly recommended that you wait a few days after pumping out the chlorine before you collect a sample to avoid false negative results.
    2. Chlorinated System: If the water system is normally chlorinated (city water, chlorinator, etc.), the sample MUST be collected in a special sampling bottle that contains a chemical to deactivate the chlorine.  These bottles have white labels.

  4. Collect the sample:
    1. Run the water at full force for at least two minutes. If the well has not been used for more than a day, run the water longer so that you will be sampling fresh water.  Reduce the flow to one-third of full force and run again for about two minutes.
    2. Open the bottle and fill it to ABOVE the "fill line" or 100 mL mark, leaving about one half inch of head space.  Be sure the bottle is held so that no water touching your hands enters the bottle and nothing other than the water being sampled touches the inside of the bottle or cap.  Put the cap on immediately.

  5. Fill out any accompanying forms:
    Fill out the sampling slip as completely as you can.  If the sample is for real estate or legal purposes, be certain that the street address and/or assessor's parcel number are recorded on the form in the field "Sampling Point".  Write the bottle number (found in the upper right corner of the sampling slip) on the bottle label.


  6. Deliver the sample:
    Deliver the sample as soon as possible to the laboratory1. If you cannot deliver the sample to the lab within one hour, keep it in a refrigerator or ice chest.  Do not expose the sample to direct sunlight for extended periods of time or allow it to get hot. If the sample is not delivered to us after sampling within the time illustrated in the list below, it is legally invalid.
    1. Drinking Water: 30 hours
    2. Surface Water: 8 hours
    3. Waste Water: 6 hours

    Samples can be dropped off Monday-Friday 8 am to 5 pm. However, samples received after 12 pm on Fridays must be run by the classic 2 – 4 day method at an additional cost.  Due to the different method being used, results may not be available until Tuesday.  If results MUST be ready by Monday, please request the expedited test ($10 extra).

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