Water Sampling Instructions
Follow these instructions to collect a sample of water to be tested by the Placer County Public Health Laboratory. If you have questions about this process, call the lab at (530) 889-7205.
Sample Bottles
Collect bacteriological samples only in sterile sample bottles provided by the Public Health Laboratory. Samples collected in any other container will not meet lab standards and cannot be processed.
There are two types of water containers available:
| Does not contain sodium thiosulfate |
Contains sodium thiosulfate (neutralizes chlorine). |
- A Real Estate Transaction
- A Report for Environmental Health
- A Report for any other county agency.
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- Surface Ground Water
- Chlorine Injection Systems
- Samples not involving Environmental Health.
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| Samples for these purposes are first tested for chlorine residue. If chlorine is detected, the sample is considered invalid and will not be tested. |
Please talk with the lab staff to determine which type container you need.
Choosing the Faucet
Choose a faucet that will provide a good representative sample of the water quality circulating in the distribution system. Following these guidelines will help you avoid having to retest your water.
| Rule |
Reason |
Comment |
| Avoid sampling from a dead end main |
the water may be old and stagnant |
A distribution system map is a helpful reference when selecting sampling locations. |
| Select faucets that are in frequent use |
may contain stagnant water and sediment which may provide a breeding ground for bacteria |
Sediment material is difficult to flush out and the sample's quality can be compromised |
| Avoid a faucet that leaks around the stem or where water "curls" back up onto the faucet mouth threads |
water may run down the outside of the faucet and contaminate the sample |
Either condition can cause a false positive sample |
| Avoid any faucet that is dusty, dirty, or corroded |
Inspect the faucet before collecting the sample |
Possible contamination |
Don't use a faucet that is close to the ground
|
Splashing spray could get into the bottle |
Possible contamination |
| Don't use a faucet that is surrounded by shrubbery or tall grass |
Dust and bacteria on the vegetation are stirred up in getting to the faucet |
Possible contamination |
| Never collect a sample from a hose or any other temporary attachment |
Debris |
Contamination |
| Don't use a faucet wrapped with insulation |
Debris |
Contamination |
| Don't sample from faucets with aerators or screens (kitchen/bathroom)* |
Debris |
Swing-type faucets are susceptible to contamination in the swing connection. |
| Sample from the cold water faucet (not hot water) |
|
Be certain the hot water faucet is not leaking (if sampling swing-type faucet) |
*If no alternative - remove the aerator and screen and let the faucet flow for several minutes before collection.
Collecting the Sample
- Collect samples only during favorable weather conditions. Do not sample during or immediately after a rain. Don't sample while a strong wind is blowing or when the air is unusually dusty.
- Do not wipe the faucet with a rag or wash it off with water in an attempt to clean the faucet prior to collecting a sample.
- Turn on the faucet and adjust it to provide a smooth flow that will permit the sample to be taken without splashing. Never open the faucet completely to flush the sample line because this may disturb sediment which is difficult to flush out.
- Let the faucet flow long enough for water to arrive from the water main itself. This time may be several minutes depending on the distance from the main to the faucet and the rate of flow. In any case let the faucet flow at least one minute (according to your watch), before you collect the sample. You will be more likely to obtain fresh water from the distribution main and avoid sampling the stagnant water that may have lain in the house plumbing or service line for a long period of time.
More Precautions:
- Remove the seal completely from the bottle.
- Open the bottle only as long as necessary to collect the sample.
- Do not lay the bottle cap down or put it in your pocket. Hold the bottle in one hand and the cap in the other. Keep the bottle cap right side up (threads down) and do not touch the inside of the bottle.
- Keep your fingers out of the bottle and hold the bottle under the faucet so no part of the faucet will touch the inside of the bottle.
- Do not rinse out the bottle.Do not wipe out the bottle. Do not blow your breath into the bottle or cap.
- Fill the sample bottle to the top of the bottle. Do not underfill the bottle. The "100 ml" line is for our information.
- Be careful that splashing drops of water from the ground or elsewhere do not get into the bottle or onto the cap.
- Cap the bottle immediately after filling and then turn off the faucet.
Deliver to the Laboratory at 11475 C Avenue, Auburn
(530) 889-7205 |
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Samples must be received in the laboratory by 4 PM the day of collection.
The Lab will accept samples between 8:00 am and 4:00 pm, Monday through Friday |
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Label the sample bottle clearly and accurately. Include:
- date and time of sample collection
- sampling point (e.g. kitchen tap)
- collector's name
- address
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After collecting the sample deliver it to the laboratory immediately. If unable to deliver immediately the samples should be refrigerated (not frozen). |