How Long Should You Flush Water Lines For Sampling
Food manufacturing facility, we use water for both cleaning and as an ingredient. We sample cold water from all throughout the plant on a monthly basis, but how long should the water lines be flushed before QC pulls the sample? Also looking for some data, white papers, university resources to back this up.
Thanks!
For general sampling procedure EPA says "2 to 3 minutes" but depending what you are sampling for, could be different.
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Food manufacturing facility, we use water for both cleaning and as an ingredient. We sample cold water from all throughout the plant on a monthly basis, but how long should the water lines be flushed before QC pulls the sample? Also looking for some data, white papers, university resources to back this up.
Thanks!
The same amount of time you require them to be flushed before using the water as an ingredient, or for cleaning. The idea is for the sample to reflect what you're using.
Which sounds like it might be zero.
Of our clients that do this the average flush time is 2 minutes.
If you're running a flush before taking a sample, I'd recommend you include that flush time for when you start using the lines then as well. If you're using the test data to say water is still suitable as an ingredient and sanitation use, you want your sampling and use procedure to mirror each other. If there's potential for growth within the line during an idle period, but you flush the lines before taking a sample, you'd never find the hazard.
It might also be worth taking a sample without a flush and then after a flush for comparison.
Hi uschle,
Any further comments /queries ?
Might this be the reason why back flow preventers are mentioned in the sqf code?
Might this be the reason why back flow preventers are mentioned in the sqf code?
No, they are to prevent sewage from entering the water system backwards and have nothing to do with the potable water sampling plan