Drive DC water pump using Arduino?

I'm looking for a way to drive a DC water pump (12V) with Arduino.
It's for a uni project so it should be as cheap as possible.
Would it be possible to control it with a transistor? 
No speed varying is needed, only ON and OFF state.

iceng20 days ago

Here is how you hook it up with a relay or directly in pic-2.

A lot depends on information you forgot to include like motor load current !

Be sure to click the pics to see a whole image :-)

rickharris20 days ago

relay. If you want better choices you need to give a lot more data - current voltage etc.