How to shock-chlorinate and test your well water

A private well means testing is on you. A common-sense schedule is to test for bacteria a couple of times a year and after any repair, flooding, or change in taste, smell, or colour, and to test the broader chemistry periodically so you know your baseline.

Shock chlorination is the standard way to disinfect a well after construction, repair, or a positive bacteria test. It involves introducing a measured chlorine solution, circulating it through the well and plumbing, letting it sit, then flushing it out before you drink the water again. Follow your provincial guidance for the amounts and contact time rather than eyeballing it.

If your water is safe but unpleasant — iron staining, hardness, sulphur smell — that is a treatment question, not a safety one. A water test tells you which problem you actually have so you are not buying the wrong equipment.

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