The owner will at some point want to peek his/her head in the basin to see what’s going on. They will know the space requirements of their equipment and can assist you in determining load.įinally, when it comes to the basin cover, think access. Whatever the case, the manufacturers of the pumping systems are the best people to turn to for a recommendation on the basin size. If the only water entering the pit is clear and is merely storm drainage, you may in this case not have to worry about room for solids, but rather a massive inflow caused by a 100-year rain. Even in applications where normal toilet waste is the only thing being drained into the pit, the debris that can build up in the pit can be stifling to a level control system. Having enough room in the pit will make it less likely to hang up controls and allows room for the necessary maintenance from above. This can destroy control systems, power cords, and eventually the pump itself. It forms a crust on the top of the water that is unbreakable by inflow. Grease rises to the top of the pit and hardens. The size of the basin can be a huge disadvantage a larger basin than normal is only a slight advantage. Grease is a very challenging media for any ejector pump. The absolute worst application in a commercial building is a basin that receives waste from a grease trap. When should one fight for that space? When is it ok to shrink the size of the pit? Any application where solids will be introduced to the basin should raise a red flag. This is where your knowledge of the application will cause you to fight for that space or make the decision to allow for a smaller pit. With that said, the demands of modern day building design may not allow for this. Most codes state that the minimum sump level is three feet below the lowest inlet in most cases, this is simply not enough.

Here is a rule of thumb for proper usable basin space: Proper level control requires a minimum of four feet from the lowest inlet to the bottom of the basin, and you need at least a foot on the outside of each pump and a foot between them (if not more) depending on the type of media you will be pumping.

Sewage ejector systems