Another thing that you could do (instead of a vibration sensor) if you just want to know when the pump is running is to plug it into a Zwave power socket that senses current draw, When the sump pump runs, the current draw goes up. You can then program an alert based on the draw to know when it’s running. You could then also alert when the pump hasn’t run for x hours. I’d still want a moisture sensor at the point where the water shouldn’t rise to, though.
See this post. @Fido is using a socket to sense motion when his security light goes off, but the concept is the same.