Can we test the water used in our facility using water testing kits?

Can we test the water used in our facility using water testing kits? If we can use such testing kits, does it need to be NSF certified or EPA certified? Can you recommend a water testing kit which is certified?

my opinion is it usually isnt worth the hassle for the following reasons. see SQF section 2.4.4

1.  You need to follow a standard method for water potability testing.  This is usually the MPN or filtration method.  "Product analyses shall be conducted to nationally recognized methods or company requirements, or alternative methods that are validated as equivalent to the nationally recognized methods."   

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2.  Because water could impact product safety, you would need to include  in your 17025 "accordance program".  "Where internal laboratories are used to conduct input, environmental, or product analyses, sampling and testing methods shall be in accordance with the applicable requirements of ISO/IEC 17025, including annual proficiency testing for staff conducting analyses."

Yes it can be done.   Potability tests are cheap, I don't think its worth doing yourself for a small operation.   If you want to do other testing on your own, that's fine.   but for the purpose of 11.5.3.2, id just send it out.