I recently worked on sizing a grinder pump for a restaurant application. Somewhat new to these pumps, I dug around for some information and came across a slideshow presentation from the Sump and Sewage Pump Manufacturer’s Association (SSPMA). It is an informative guide for someone not familiar with sump and sewage. I came to realize that sizing sump and sewage pumps is not so different from sizing water pressure booster pumps. The underlying resource is the Hunter’s Curve. Tally up your fixture unit count, and reference the curve to find out the GPM. For TDH, the same rules as always apply – static head + friction head.