Sewage & Ejector Pump Sizing

Sewage pumps (ejector pumps) move raw wastewater from below-grade fixtures or lift stations to the building drain or sewer. These pumps handle solids and require careful basin design to prevent clogging and ensure adequate cycle times. Plumbing Booster supports an optional ASPE lift-station design review based on ASPE Plumbing Engineering Design Handbook Volume 3.

1. **Determine inflow rate** - From drainage fixture units or manual design flow. 2. **Size basin** - Volume for adequate cycle time (minimum runtime, maximum starts per hour). 3. **Calculate TDH** - Static lift + friction losses + residual head + minor losses. 4. **Select pump type** - Sewage-rated pump capable of passing solids (minimum 2" solids handling). 5. **Check arrangement** - Simplex (single pump) for small systems, duplex (two pumps) for reliability, triplex for large systems. 6. **Optional ASPE review** - Basin capacity per ASPE Table 11-9, flotation analysis per Table 11-10.

Plumbing Booster includes an optional ASPE lift-station design review checklist: - Highest instantaneous flow basis verification - ASPE Table 11-9 basin capacity review - ASPE Table 11-10 flotation (uplift vs resisting force) review - Anti-flotation measures confirmation - Mostly fixture-effluent review for design margin - Wide flow variation consideration - Same-capacity pump recommendation for duplex/triplex - Vent/gasketed cover, guide rails, washdown provisions - Minimum water depth, turbulence, sloped floor - Force-main appurtenances and material review The review is advisory - it provides professional guidance without blocking calculations.

A basement lift station serving a restroom group: - Inflow: 20 GPM (from DFU calculation) - Static lift: 12 ft (basement to building drain) - Discharge pipe: 2" PVC, 50 ft length - Friction loss: ~3 ft - Minor losses: 2 ft - Residual head: 2 ft - **TDH = 12 + 3 + 2 + 2 = 19 ft at 20 GPM** - With 10% margin: 19 x 1.1 = 21 ft Basin: For 10-min cycle at 50 GPM pump rate: Volume = 50 x 10 / (1 + 50/20) = 500/3.5 = 143 gallons Select: Duplex sewage pump package, 50 GPM at 21 ft TDH, 2" solids handling.

In the Pumps module, select "Sewage" as the pump system type. Enter inflow parameters, basin dimensions, and discharge piping. The software calculates TDH, cycle time, and validates against ASPE criteria if the review is enabled. The Summary page recommends simplex/duplex/triplex arrangements and provides advisory notes.