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Sampling Procedures

For Total Coliform and E.Coli testing


Do not collect the sample until you are ready to drop it off for processing!

Sample must not be more than 30 hours old at time of processing!

The container must remain sealed until you are ready to collect the sample.

Sample container has sodium thiosulfate in it. DO NOT RINSE!


Step 1. Locate the faucet closest to the pressure tank that is a rigid, metal faucet. Do not take a sample from yard or wall hydrant, a hose, or a plastic fitting of any kind. Do not take a sample from a swing-type faucet. False positives are highly probable in those locations.

Step 2. Remove any faucet screens or attachments. Wash your hands thoroughly with soap and water.

NOTE: Do not sample from faucets with an aerator, unless the aerator has been removed.

Step 3. Turn on the cold water on another faucet and allow it to run during the entire sampling process (approx. 15 minutes). Turn on the cold water at your sample faucet and allow it to run for at least 5 minutes.

Step 4.*Sanitize your sample faucet with a direct flame by using a lighter, alcohol swab, or a propane torch. Before starting this step, make sure that the faucet has no plastic parts. Please be aware that flaming the faucet may leave a carbon residue on the outside of the faucet. This is acceptable for test purposes. Wipe this residue off the faucet AFTER taking the sample. 

*This step is only needed for samples that will be tested for E.coli or total coliform.

          CAUTION: Always be cautious of open flames to avoid burns and keep away from children.

Step 5. Remove the top from the sample bottle, being careful not to touch the inside of the cap or the mouth of the bottle.

Step 6. Fill the sample bottle to or above the 100 ml line on the bottle. There must be at least 100 ml of sample in the bottle or the sample cannot be accepted for testing. NOTE: Do NOT overfill the bottle or rinse out the chemical in the bottle. The chemical is harmless, but necessary for the analysis process.

Step 7. Replace cap securely. Complete the Sample Receipt form as fully as possible. Samples that do not have a sample date & time on the Sample Receipt form cannot be tested. Store the sample in a cool location prior to returning it to the office.

Step 8. Bring the sample to our office as soon as possible. For the most accurate results, sample should be received within 4 hours of collection. However, up to 30 hours from collection time, is acceptable. Storing the sample in a cooler or refrigerator may be necessary to protect the sample from extremes of heat or cold. Samples that are older than 30 hours will not be tested.  NOTE: If you are shipping the sample to us, select a delivery service that will deliver the sample to our office within 30 hours from collection time. It is YOUR responsibility to ensure delivery within the time limit.

If you are sending a sample by a delivery service, please send it to: 1075 West Main St, Christiansburg, VA 24073.

Step 9. Please pay the testing fee at the time the sample is brought to our office. You may include a check with the sample if you are dropping it in our drop box. If you would like to pay by VISA/MasterCard/Discover and are leaving it in our drop box, enclose contact information so that we can call you to get your credit card information.

 For Evaluation Samples:

Evaluation Samples are FREE because this is a NON-CERTIFIED test. It is performed using field test equipment and methods and can usually be performed right in front of you. In fact, we prefer it this way so that YOU will understand what the test results mean.

There are no special requirements or methods for taking your Evaluation Sample. We suggest that you stop by the office and pick up an Evaluation Sample bottle out of our drop box, but we can take the sample from any CLEAN bottle. The bottle does not have to be sterilized in any way, just well rinsed and with no food residue in the bottle.

If you are wanting to find out if your existing water treatment equipment is still working the way that it is supposed to, bring us an Evaluation Sample from BEFORE the water treatment equipment and one from AFTER the water treatment equipment. There is no charge for bringing in multiple Evaluation Samples.

For Additional Testing:

Please contact the office for pricing, sample bottles, and sampling instructions.