General Contact Number: (530) 621-5567

Environmental Health

Instructions for Taking Water Samples

1. Select a sampling faucet which is clean and in frequent use, discharges downward and provides a smooth, uniform flow.

2. Remove any faucet attachments, such as grit screens, strainers, hoses, etc.

3. Flush the cold water faucet thoroughly to remove stagnant water from the supply line, allowing water to run for at least 3 to 5 minutes.

4. Adjust flow rate for sampling, making sure water is not lapping over the faucet rim and tap is not leaking.

5. With clean hands, open the container by first removing the plastic protective ring and while holding the cap by fingertips, fill the bottle with a constant stream of water until bottle is filled up to the bottom of the bottle neck, (past the fill line). Leave 1/2 inch air space and replace cap. If container overflows, obtain another and try again. (Do not rinse out powder inside bottle - used to neutralize any chlorine present)


** Do not let container or cap touch the faucet or let your fingers touch the lip of the container or come in contact with the water as it fills the container.

6. Replace cap, then turn off faucet, and replace the attachments.

7. Keep cool and deliver to the laboratory as soon as possible. Ideal time is within 2 hours, and samples over 24 hours old will not be analyzed. It is best to collect the sample immediately before delivery to the laboratory.

** The laboratory will not accept samples that are warm. We suggest keeping the sample in an ice chest while transporting it to the laboratory, especially on warm days.