EMP ?

EMP is like a huge burst of radio waves, any metal object will absorb it like an antenna and produce a voltage spike. The power grid is a huge antenna, the power pumped into it will be massive. About all you can do is connect lighning arrestors to all your critical equipment and hope the power grid is similarly protected. If you have any warning, disconnect the equipment. Simply throwing a switch leaves a very small gap for that surge to jump, pull wires and move them far away.

Shady's advice to rock solid!

I think they make mention of this at the link... if not they certainly have advice on how best to protect it...
http://www.textfiles.com/survival/emp.pro

A big part of recent testing indicates that surrounding environment is important. Steel girders and such nearby can focus these effects...

I'd hazard to say that anything as simple as a common electric motor, given windings/brushes/internal wiring of a sufficiently heavy gauge, would easily survive an EMP. The control circuitry is possibly a whole 'nother story, but in a SHTF scenario you'd want to switch to a scheduled-pump usage style rather than pump-on-demand anyway, so you could just hook the wires directly to an appropriate power source when you were going to get some water.