General Sampling Procedures
This summary document is designed to be used by personnel trained in the collection of drinking water samples and handling of sample preservatives. We have decided to share this information with our clients so you can see how carefully and seriously we take our position in the industry. All samples collected by our operators follow the procedures described below to assist in the collection of an acceptable sample and to maintain the integrity of the sample after collection.
- Prepare a Sampling and Analysis Plan (SAP) which describes the sampling locations, numbers and types of samples to be collected, and the quality control requirements of the project.
- Check with the laboratory before collecting samples to ensure that sampling equipment, preservatives, and procedures for sample collection are acceptable. It is best to obtain sampling supplies directly from the laboratory performing the analyses. Gather all equipment and supplies necessary for the project.
- The acids and bases used in preservation of many types of samples described in this document are dangerous and must be handled with care. Always wear gloves and eye protection when handling preservatives. When opening a preservative bottle, particularly a glass ampoule, break open the ampoule away from yourself and others. Have acid/base neutralization supplies (baking soda) on hand in the event of a spill.
- Collect samples in an area free of excessive dust, rain, snow or other sources of contamination.
- Select a faucet for sampling which is free of contaminating devices such as screens, aeration devices, hoses, purification devices or swiveled faucets. Check the faucet to be sure it is clean. If the faucet is in a state of disrepair, select another sampling location.
- Collect samples from faucets which are high enough to put a bottle underneath, generally the bath tub or kitchen sink, without contacting the mouth of the container with the faucet.
- If you are collecting a first-flush sample for lead/copper, allow the water to run just a bit before collecting the sample but do not flush the lines as you want to collect a sample which has been in contact with the distribution system pipes for at least six hours.
- If you are collecting other types of samples, open the faucet and thoroughly flush. Generally 2 to 3 minutes will suffice, however longer times may be needed, especially in the case of lead distribution lines. Generally, the water temperature will stabilize which indicates flushing is completed. Once the lines are flushed, adjust the flow so it does not splash against the walls of the bathtub, sink or other surfaces.
- Follow the collection instructions provided for the analytes of interest described on the following pages. Wear eye protection and gloves if you are handling containers with acidic/basic preservatives and when you are collecting samples.
- Use a sample tag to record the site location, name of the sampler, date and time of collection, method of collection, type of analysis to be completed, and preservative in se. Attach the sample tag to the bottle.
- Fill out the chain of custody form with the sample collection information.
- Deliver or ship samples to the laboratory to ensure that holding times are met.
- Return empty preservative containers to the laboratory for proper disposal.