What is a Submersible Sewage Pump and When Do You Need One?
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What is a Submersible Sewage Pump and When Do You Need One?
Submersible sewage pumps are one of the most important and most specialized pieces of equipment in municipal and industrial water management. They're built for one of the toughest jobs in the industry — moving raw sewage continuously and reliably in demanding conditions.
Here's everything you need to know about submersible sewage pumps and when your project requires one.
What is a Submersible Sewage Pump?
A submersible sewage pump is an electric pump designed to operate fully submerged in wastewater or sewage. Unlike surface mounted pumps that sit above the water and use suction to draw fluid up, a submersible pump is lowered directly into the wet well, sump, or collection chamber and pushes fluid upward through a discharge pipe.
The motor and pump assembly are sealed in a waterproof housing that protects the electrical components from the liquid being pumped. This sealed design allows the pump to operate submerged indefinitely without damage to the motor.
How is a Sewage Pump Different from a Standard Submersible Pump?
Not all submersible pumps are created equal. A standard submersible pump is designed for clean or lightly contaminated water. A sewage pump is specifically engineered to handle:
- Raw sewage with solids — human waste, toilet paper, wipes, and other materials that would destroy a standard pump
- Continuous duty operation — sewage never stops flowing. Sewage pumps run 24 hours a day 365 days a year in permanent installations
- Corrosive and abrasive fluids — sewage is chemically aggressive. Sewage pumps use materials selected for corrosion resistance
- Large solids passage — sewage pumps have specially designed impellers that pass solids up to 3 inches in diameter without clogging
Key Components of a Submersible Sewage Pump
Motor — a hermetically sealed electric motor designed for continuous submerged operation. Available in single phase for smaller residential applications and three phase for commercial and municipal use.
Impeller — the rotating component that moves sewage through the pump. Sewage pump impellers are designed to pass solids without clogging. Common designs include vortex impellers and semi-open impellers.
Mechanical seal — prevents sewage from entering the motor housing. The most common failure point on a sewage pump. Quality pumps use double mechanical seals with an oil chamber between them for added protection.
Pump housing — cast iron construction on commercial and municipal grade pumps for durability and corrosion resistance.
Discharge connection — connects to the force main or bypass line. Sized to match the required flow rate.
When Do You Need a Submersible Sewage Pump?
Municipal lift stations — the primary application. Every lift station in a municipal wastewater system uses submersible sewage pumps to move wastewater from lower elevations to higher ones. Typically installed in pairs — one duty pump and one standby.
Bypass pumping during sewer maintenance — when a section of sewer main needs to be taken offline for repair or rehabilitation a submersible sewage pump bypasses the flow around the work zone. The pump is lowered into the upstream manhole and pumps sewage through a temporary bypass line to the downstream connection.
Lift station maintenance — when a permanent lift station pump needs to be removed for maintenance a portable submersible sewage pump provides temporary pumping capacity while the permanent pump is out of service.
Emergency response — pump failures at lift stations and sewage overflow events require immediate deployment of portable submersible sewage pumps to restore flow and prevent environmental damage.
Industrial wastewater — manufacturing facilities, food processing plants, and other industrial operations that generate process wastewater with solids use submersible sewage pumps for collection and transfer.
Construction dewatering near sewage infrastructure — certain construction applications near active sewer infrastructure require pumps capable of handling contaminated water.
Key Specifications to Understand
Flow rate (GPM) — how much sewage the pump moves per minute. Must meet or exceed peak flow for the application.
Total Dynamic Head (TDH) — the total resistance the pump must overcome including elevation change and friction losses. Always select based on performance at operating TDH not maximum GPM.
Solids handling — the maximum solid size the pump can pass without clogging. For municipal sewage applications minimum 2 inch passage, 3 inch preferred.
Motor size (HP) — larger motors handle higher flow rates and head pressures. Must be matched to the application requirements.
Voltage — single phase 115V or 230V for smaller pumps, three phase 230V or 460V for commercial and municipal applications. Must match available power supply.
Duty rating — continuous duty for permanent installations. Intermittent duty for portable emergency applications.
Selecting the Right Submersible Sewage Pump
To select the right pump for your application you need:
- Required flow rate at peak conditions
- Total dynamic head at operating conditions
- Maximum solids size in the sewage stream
- Available power supply voltage and phase
- Physical constraints — manhole diameter, submersion depth
- Duty requirements — continuous or intermittent
How Flowcor Equipment Supports Sewage Pump Applications
Flowcor Equipment supplies submersible sewage pumps to municipalities, utility contractors, and industrial facilities across the U.S. We source from leading manufacturers including Tsurumi, Gorman-Rupp, Xylem, and more.
Tell us your flow rate, head pressure, solids handling requirements, and application and we'll get you a quote within 1 business hour.
Submit a quote request at flowcorequipment.com or call us at 610-241-6770