I suspect a leak in your water line near the footing tile. The water will take the path of least resistance so there is no guarantee it will come to the surface. Simply shut off the water at the pit in the street and see if your sump stops running after a while. If there is a pit in the street, which I would think there is. The city should be responsible for everything up to the meter, I would think.

Having a sump running pretty much constantly cannot last for long without buring up the motor unless it is some kind of a premium pump.

You don't want to tarry on figuring this out.

Good luck.

Tom W

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.