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Method for Collecting Drinking Water Samples For Bacteriological Analysis

This method is for collecting potable (drinking) water samples. Only samples collected in bottles prepared by American Environmental Laboratories and collected in accordance with these instructions will be accepted for analysis.

DO NOT OPEN BOTTLES UNTIL ALL INSTRUCTIONS HAVE BEEN READ!

The sample should be taken from a smooth-nosed cold-water tap if possible. Avoid collecting samples from leaking taps that allow water to flow over the outside of the tap, from frost-proof hydrants or hot-cold mixing faucets, since it is not practical to sterilize these fixtures.

  1. Prepare a sanitizing solution of bleach water or alcohol solution
    1. Bleach water (1/4 cup bleach and 2 cups water)
    2. Alcohol solution (full strength rubbing alcohol)
    3. Place sanitizing solution in a spray pump bottle and adjust to squirt solution
  2. If present, remove aeration devices and screens from faucets before sampling.
  3. Open the tap fully and let water run to waste for 2 or 3 minutes or until the service line has been thoroughly flushed.
  4. Chemically disinfect the tap by thoroughly rinsing the inside and outside of the tap with a 100-ppm solution of sodium hypochlorite (bleach water).  If tap cleanliness is questionable, provisions should be made to allow the solution to remain in contact with the tap for up to 15 minutes or to increase the strength of the solution to ensure adequate disinfection.
  5. Flush the tap for an additional 2 or 3 minutes, and then reduce to a gentle flow to permit filling the bottle without splashing.
  6. KEEP BOTTLE CLOSED UNTIL IT IS TO BE FILLED and DO NOT RINSE THE SAMPLE BOTTLE. The bottles contain a chlorine neutralizer that is present in liquid or crystalline form.  They are sterile and ready for use when shipped.       Note:   A loose cap does not affect sterility.
  7. Grasp the cap alone the top edge and remove.  DO NOT TOUCH THE INSIDE OF THE CAP OR THE BOTTLE, AND DO NOT ATTEMPT TO CLEAN OR RINSE THE BOTTLE.
  8. Hold the bottle so that water entering it will not come in contact with your hands.  Allow water to flow smoothly from the tap and fill the bottle, leaving ½ inch air space at the top.  The bottle has a fill mark on the side.
  9. Replace cap on bottle and tighten securely.
  10. Place the sample bottle in a cooler with ice and deliver to the lab in less than 24 hours.