Drinking Water Sampling Instructions

Follow the directions below to correctly sample your drinking water. All samples must be brought in for analysis within 24 hours of being taken. If you have any questions please feel free to call us!

  1. Collect samples from a cold tap. Do not sample from hoses, drinking fountains or faucets that swivel. Remove aerators and bypass the softener. Run the water for one minute before sanitizing.

  1. Sanitize the tap by spraying a 5.25% bleach solution (1Tbsp. per half gallon) on the surface and underside of the tap. A bag of the bleach solution can also be placed over the tap with squeezing to flush the tap. Do this for two minutes, using a fresh bag and solution for each tap being tested.

  1. Turn on the tap and let the water run for 3 to 5 minutes or until a constant temperature is reached.

  1. Reduce the flow from the tap to avoid splashing.


  1. Remove the cap from the sterile sample bottle. Do not tough the mouth of the bottle or the inside of the cap with your fingers or any other surface.

  1. Do not rinse the bottle out! Fill the bottle to the 100mL line. Do not over fill. Immediately put the cap back on the bottle.


  1. Bring the sample to North Coast Environmental Labs the same day that you take the sample. Fill out the appropriate forms that will accompany your sample. For a public drinking water sample fill out form EPA 5211 and for a private drinking water sample fill out the Private Water Supply Microbiological Sample Report.


  1. North Coast Labs accepts drinking water samples Monday – Thursday between 8am and 3:30pm. The test takes 18-24hours to complete.