Why does my well water smell bad after it rains?
A smell that follows rain means surface water is reaching your well. Rain pushes water and everything it carries through gaps a sealed well should not have: a loose cap, a cracked casing, or poor grading around the wellhead. Treat it as a warning, test for coliform bacteria, and fix the entry point.
Walk the wellhead after the next storm: the cap should be tight and vermin-proof, the casing should stand clear of ponding water, and the ground should slope away. A failed cap gasket is the cheapest fix in well ownership and the most common answer.
After sealing the doorway, shock the well to clear what came in, and retest. A well that smells after every rain and keeps failing tests despite a sound wellhead needs a contractor to look at the casing itself.
Want the dose sized to your exact well?
We pull your well's dimensions from your state's official record and pack a chlorine dioxide kit to them, from $399.
Find my wellGo deeper