Information
Proper Water Sampling Techniques
Water to be tested for Coliform Bacteria or E. coli must be collected in one of our sterile, sealed, properly preserved 120mL containers. Obtain a container from our main lab or one of our drop-off sites, or simply call us and we'll mail one to you. Only bacteria can be tested from this container; if you would like to test for anything else, like Nitrate or Lead etc., you MUST obtain a different bottle.
Collecting a Bacteria Sample: Completely remove the seal from your sample bottle and discard. The white powder in the bottle is normal. Never rinse the container. Do not touch the inside of the cap or bottle at any time. Use a cold water tap that does not have an aerator, sprayer, hose, filter or back-flow valve. Try to find a faucet that has a separate hot and cold handle if possible. Remove any aerators from the faucet. Purify the faucet by spraying bleach inside on on it or by using a flame for 10 seconds. Turn on the cold water only and let the faucet run for at least 1 minute, or long enough for you to detect a temperature change. Reduce the flow to a steady stream, remove the cap (do not set it down) and fill the bottle up to the 100mL fill line. Try not to over fill the bottle above the line, but ensure that you collect at least 100mL. Replace the cap and place the bottle on ice in a Ziploc bag or cooler. Deliver the sample to the lab within 30 hours from the time you take the sample and keep it on ice the entire time. Results will be mailed or faxed the next day.
Shock Chlorination of a Well
If the Bacteria Test of your well water is found to have Total Coliform Bacteria or E. coli present, that means your well is contaminated and non-potable; YOU SHOULD NOT drink or bathe in water that has Coliform Bacteria present. Your choices are to resample the well, ensuring you followed all of the above suggestions, or to treat your water system. Often, a simple, quick "shock chlorination" of your well will yield water that is free of coliform bacteria. Valley Lab can perform this well treatment for you at a cost of $120, or you can perform this treatment yourself by following the directions of the link below.
Shock Chlorination Procedure: http://www.ncdhhs.gov/docs/welldisinfect.pdf
Resample the water after all of the bleach is rinsed out to ensure that you have killed the bacteria and don't have a constant, on-going problem with contamination. If you still have bacteria present after 2 complete chlorinations, you may have a leak or another on-going source of contamination. If your well continues to test positive for coliform bacteria and there is no leak, you may need to consider a permanent treatment such as a UV light or chlorinator.
Links
WA Department of Ecology http://www.ecy.wa.gov
WA Department of Health http://www.doh.wa.gov
The NELAC Institute http://www.nelac-institute.org
SPECIAL NOTES:
We cannot be responsible for holding times that are exceeded for samples delivered on weekends or after 5 p.m. on weekdays without prior notification and approval. Please call the lab if you are unsure about special containers or sampling procedures. VALLEY Environmental Laboratory reserves the right to refuse service to anyone. Prices and methods are subject to change without notice.
Valley Water Services