Having discussion on the subject with several folks. Some say the pumps are required to have explosion proof motors. Some say they are not. What say you?
NFPA 820 along with NEC defines the classifications for Wastewater Treatment and Collection Facilities.
Wastewater Pumping Station Wet Wells are classified as Class 1 Division 1, Group D without venting and can be classified as Class 1 Division 2, Group D with venting creating 12 air changes per hour.
Class 1 areas require FM rated pumps and intrinsically safe electrical sensing equipment, further, Class 1 Division 1 requiring explosion proof equiptment. It is important to consider space classification in Electrical Design and selection of the wet well components.
Also, since you have no idea of what will come down the pipe, it is better to pay a little more and not blow up the station and many toilets in buildings. Some of the things that might come down the pipe, gasoline, paint, paint thinner, motor oil, auto parts cleaner and many more organic substances. If it can be flushed, it will be flushed.