· Michael Blair
A sump pump moves collected groundwater away from the house. Both halves of that — the collection and the moving away — have to work, and so does the power.
The discharge
It must go far enough away that the water does not simply return to the perimeter drain and cycle. Discharging beside the foundation creates a loop that runs the pump continuously.
The line also needs to avoid freezing and be routed so it cannot be blocked, with an air gap or check valve as appropriate.
Backup power
Middle Tennessee storms that produce the groundwater also take the power out, which is precisely when the pump is needed. A battery backup or a water-powered backup addresses it.
A pump without backup is a pump that works except when it matters.
- Discharge well away, not back onto the perimeter
- Battery or water-powered backup, not optional here
- Check valve to stop backflow into the pit
- Test the pump before the wet season
- Never discharge into a sanitary sewer
Testing it
Pour a bucket of water into the pit and confirm the float rises, the pump runs and water leaves the discharge outside. Do it before winter and again in spring.
A seized pump looks identical to a working one until it is called on.
Never into the sewer
Discharging a sump into a sanitary sewer is generally prohibited and it overloads treatment during exactly the storms that stress the system.
It also risks sewage backing up into the house. The discharge belongs on the surface, well away from the foundation.