Max allowed inductive load (pump) for a given relay
For motors, you should be looking at relay ratings that specifically apply to motors. For NEMA ratings (USA) look for horsepower (Hp) ratings. For IEC ratings (worldwide) look for IEC Utilization categories.

For the  Omron G5RL-1A-E-HR relay, use the ratings highlighted below. LRA and FLA mean motor locked rotor and full load amps



Note that the number of test operations is 6,000 for the motor ratings vs. up to 50,000 for the other ratings. The number of test operations is probably a good indication of the expected life. For longer life, you might consider using a motor contactor. If the relay is switching a lower current than the maximum rated current listed, that should extend the life. Look at the Moron durability curves.