SEWER EJECTOR PUMP — BASEMENT BATHROOMS THAT STAY DRY

A sewer ejector pump is the answer whenever a fixture — toilet, shower, washing machine, sink — sits lower than the gravity sewer line running out of the house. Salt Lake Valley basements are almost universally below the city main in the street, which means any basement bathroom or laundry stack that drains to code needs a way to push waste uphill to the main. That way is an ejector pump, housed in a sealed basin, triggered by a float switch, discharging through a check valve into the gravity sewer above.

Ejectors handle raw sewage — solids, toilet paper, grey water, everything. That's what separates them from sump pumps (which only move clean ground water) and from lift stations (which handle municipal-scale volume). The pump itself sits in a 30-40 gallon polyethylene or fiberglass basin buried in the slab or tucked into a utility room corner. A sealed lid with a vent pipe keeps sewer gas contained. A float switch tells the pump to run when waste rises to a set level. A check valve on the discharge line keeps already-pumped waste from draining back down when the pump shuts off.

When you need one

• New basement bathroom or wet bar in a finished basement where the rough plumbing is below the main sewer
• Basement laundry stack that's being added below the main floor drain line
• Garage utility sink sitting lower than the house sewer
• Mother-in-law apartment or ADU finished in a basement or walkout
• Replacement of an existing failed pump — ejectors last 7-12 years in residential applications
• Commercial properties with below-grade tenant space, basement kitchens, or restroom clusters below the main lateral

The three pump types we install

Simplex ejector. Single pump, single float switch, single basin. This is the standard residential install — one basement bathroom, one pump, one line running up to the house main. Usually 1/2 HP with a 2-inch discharge. Lifespan: 7-10 years. Cost: $1,950-$3,400 installed.

Duplex ejector. Two pumps in the same basin, alternating on each cycle so wear is shared and one is always available as backup. This is what goes into rental properties, ADUs, small commercial, and any installation where a pump failure means a homeowner is dealing with sewage in the basement before the plumber arrives. Costs more up front but cuts the downtime risk in half. Cost: $3,400-$6,200 installed.

Grinder pump. A grinder uses a rotating cutter impeller to chop solids — including flushable wipes, feminine products, dental floss, anything a standard ejector might bind on — into slurry before pumping. More expensive, more prone to motor wear from fibrous material, but the right answer on any installation where the user base includes children, renters, or commercial traffic. Also required when the discharge line runs over 150 feet or has multiple elevation changes. Cost: $2,800-$5,400 installed.

Why Utah installations have specific failure modes

Two Utah-specific problems show up in ejector failure calls. First: hard water mineral buildup on float switches. Utah's high-calcium municipal water means the waste in an ejector basin has dissolved mineral content, and the vertical float shaft develops a scale coating over 3-5 years that prevents the float from sliding freely. Symptom: pump runs constantly or fails to trigger at all. Fix: switch to a pressure-sensor float or schedule annual descale on the existing float assembly.

Second: freeze damage on discharge lines. A below-grade ejector discharge running up through an exterior wall to an above-grade tie-in can freeze in a Utah February if the wall is poorly insulated or the discharge line runs in an unheated crawl space. Symptom: pump runs but no waste reaches the main. Fix: re-route discharge through conditioned space, or insulate and heat-trace the line.

What we do on an ejector install

Every new install starts with a plan review — fixture count, waste output calc, discharge lift height, run length, and code compliance check for the city (SLC, Sandy, West Jordan, Draper, Midvale all have distinct plumbing code interpretations). We pull the permit, size the pump and basin correctly for the application, run the 1.5-inch or 2-inch discharge up through conditioned space, install the check valve and gate valve on the discharge, wire to a dedicated 20-amp circuit with GFCI protection, install the sewer gas vent tied to an existing plumbing vent or to a separate through-roof vent, and install an audible/visible alarm on the basin.

On replacements, we diagnose the failure (float, motor, check valve, discharge line, basin seal), quote the right repair vs. replace decision, and pull the permit if basin or discharge modifications are required. The old pump is pulled, the basin is cleaned, the new pump is dropped in, the float is adjusted, and the system is cycled and confirmed before we leave.

Annual service visits are available on the $79/year Quality Service Club membership — worth it for anyone depending on an ejector pump for a rental property, ADU, or high-traffic basement bathroom. The annual check includes pump cycle test, float free-movement verification, alarm test, discharge line flush, and basin cleaning.