Sampling Protocols for Collecting a Tap Water Sample for Lead Analysis

Ask the Expert Question:
What are the sampling protocols for collecting a tap water sample to analyze for lead?
Expert Response:
There are 2 guidelines for collecting a sample for the testing for lead.

According to EPA's lead and copper rule for drinking water, it is recommended that you collect a first-draw sample from a tap where the sample has stood in the pipes for at least 6 hours (e.g., no flushing, showering, etc.). First draw samples collected at single-family residences should be drawn from the cold-water kitchen tap or bathroom tap. Collect the sample into a 1-liter poly container. The laboratory can acidify the sample upon receipt for preservation.

For water quality monitoring, the sampling guideline indicates that the water source should be fully flushed for 10 minutes. Then collect the sample into a 500ml (or 250ml) poly bottle preserved with nitric acid.

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Blue ice for shipping laboratory samples

Ask the Expert Question: 

Can blue ice be used to ship samples to the laboratory?

Expert Response: 

The requirement is to receive environmental samples at 6 degrees Celsius. Any means that can ensure the 6 degree requirement would be suitable. However, it has been demonstrated that blue ice or cooler packs are very poor at lowering sample temperatures to the 6 degree requirement when the sample temperatures upon collection already exceed that temperature. This can result with sample temperatures being above the required temperature when received at the laboratory.

Ice however, will lower sample temperatures even when collected above the desired temperature if there is sufficient contact time between collection and receipt at the laboratory, and when there is sufficient ice to last the journey to the lab. Also, if the trip to the lab is short in duration, it may be necessary to chill the samples in the field prior to packing them for shipment.  Therefore, Ice is the preferred cooling mechanism, and some local enforcement bodies make it a requirement.