How To Collect A Water Sample


Stop by our office and pick up containers and a Chain of Custody form. Please do not open container(s) until sample is to be taken.

Use an inside faucet. Use faucets that have separate hot and cold handles. Bath fixtures are a good choice. Avoid swivel taps, such as those found at kitchen sink, as these faucets have a greater chance of harboring bacteria. Remove all attachments from the faucet, including aerators, screens, hoses and/or filters.

Turn on cold water only and let it run with a steady stream for at least 5 minutes. Before collecting the sample turn the water down so that the stream is about the width of a pencil, then let the water run for one minute.

When you are ready to take the sample hold the bottle near the bottom and unscrew the cap. Avoid touching the edge of the cap, and avoid splashing it as the sample is collected. Do not touch the inside of the cap or bottle.

Fill the water to the 100 mL line, do not allow it to overflow. Do not rinse the bottle before taking sample. The bottle contains a small amount of white powder (dechlorinating agent) that is a necessary chemical for the analysis.

Replace the lid as soon as the bottle is filled and removed from the flow. Keep sample in the refrigerator or on ice until it is returned to the lab. Samples must be returned within 24 hours of collection.

Fill out the lab slip with name, address, phone number, time and date of collection, and public system information if required.



Stop by our office and pick up containers and a Chain of Custody form. Please do not open container(s) until sample is to be taken. For single tests, you may have received a 250 mL plastic bottle. For multiple tests, you will receive a collapsible cube container. The plastic bottles that we provide free of charge are certified to be free from contaminants. If you choose to collect in your own container, we can not assure the container is acceptable and free of contaminants.

If you received a cube container, remove cap and inflate cube completely by blowing into the opening. As this container is for inorganic tests, you will not contaminate the sample by blowing into the container.

If sampling from inside a residence, remove all attachments and/or filters from the faucet before taking the sample. Turn on cold water only. Do not take sample from a hose or hot water faucet. For water systems testing for nitrate and most other inorganics, sample directly from a point representative of the source, after treatment, and prior to entry to the distribution system.

If you are sampling metals from your plumbing, take the sample(s) first thing in the morning without running the water first. Water should have been standing for at least six hours but not more than twelve hours. The sampling location should be from where you draw most of your drinking water.

Make sure cap is secured tightly. Label container(s) with name, address, or other identifier. Keep sample(s) in the refrigerator or on ice until returned to the lab.

Complete the Chain of Custody / Water Sample Information form with name, address, phone number, date and time of collection, location and source of sample(s), analysis needed, and public system information if required. Standard turn-around time for results is 6-10 working days from receipt of the sample unless arrangements are made (this time may vary depending on the analysis). If testing is a compliance sample for a public water system, the lab will send a copy of the report directly to the Washington State Department of Health.

Return samples to the laboratory within 48 hours of sampling.


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