Water supply line to sump pit

[Jody Humbert]

Why would there be a water line plumbed to the sump pit? It has a shut-off valve just out of the picture. It releases water straight from the main when the float raises to it's set level. Any information would be greatly appreciated. This is the first time I have ever seen this. Thanks ahead for any help.

[Jody Humbert]

Ooops! Might help if I attach the photo!

[neal lewis]

It could be a water powered sump pump. Works on a syphon principle.

[Rick Sabatino]

I knew a guy that set up a water line to wash out the sump pit. He felt it might cause an odor if left sitting because he rarely got any water and the pump would always leave a little in the bottom.
He was an engineer. One of the old breed that could do anything.

[Dom D'Agostino]

Here is a video (http://www.pbs.org/thisoldhouse/videos/viewer.php?item=sump)from the TV show Ask This Old House showing a backup sump pump powered by city water.

Dom.

[Jody Humbert]

Thanks for the replies. Dom, I think the video explains it all. It appears to be a city water powered back-up pump.

[Ron Hasil]

Most plumbing codes do not allow the water powered pumps. Here in Illinois they are not allowed, I know in other States, that do allow them require an RPZ valve to be installed on the supply to the pump.