Newly installed sump pump sitting in a basement sump pit

Sewer gas smell around a sewage ejector basin

A sealed sewage basin should not smell. Odor almost always means a leaking lid gasket, a missing bolt or grommet, an open conduit hole, or a basin vent that is blocked, frozen or missing. Dry floor-drain traps nearby can mimic the problem. Hydrogen sulfide is toxic, so treat ongoing odor as a safety issue.

Cross-checked ~60 min moderateBrands: All

Before you start

Hydrogen sulfide is toxic and dulls the sense of smell: ventilate, leave if odor is strong or anyone feels unwell
Never enter the basin; confined space
Lock out the pump and close the discharge valve before opening the lid
No sparks or flames near an open basin (methane)

Diagnostic steps

Unlock all 6 steps with expected values

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