I'm designing a wet well (first time)and am seeking information on the distance from the inlet pipe to the wet well and suction pipe to the pump.  To avoid influent vortexing from creating air pockets and thus caviation for the suction pipe, there should be a minimum distance between the two but I haven't found a discussion anywhere about what this distance should be.  Anyone have a resource?

The inlet should not impinge against the pump, jet directly into the pump inlet, or enter the pit in such a way as to cause rotation of the liquid in the pit.  The sump inlet should be as far away from the pump as the geometry will permit. A distribution nozzle can be used to prevent jetting.

Pump centerlines should be 1 1/2 to 2 diameters (of suction bell) apart. Keep flow in pit below 1 ft/second.

This information is available from the Hydraulic Institute and is also reprinted in the back of the Gould