Septic aerator vs. sump pump: running cost
A sump pump is cheaper to run: about $16 a year versus $126 for a septic aerator at typical use and 17.99¢/kWh, a $110 difference.
| Septic aerator | Sump pump | |
|---|---|---|
| Typical watts | 80 W | 800 W |
| Watt range | 40–500 W | 400–1,300 W |
| Typical use | 24 hours a day | 18 minutes a day |
| Energy per year | 701 kWh | 88 kWh |
| Cost per hour | 1.4¢ | 14¢ |
| Cost per day | 35¢ | 4.3¢ |
| Cost per month | $10.51 | $1.31 |
| Cost per year | $126 | $16 |
| Per year in Hawaii (43.51¢) | $305 | $38 |
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What drives the difference
- Septic aerator: Aerobic treatment units run an air pump continuously; linear diaphragm pumps draw about 40-120 W (350-1,000 kWh a year), older rotary compressors 250-500 W.
- Sump pump: A 1/3 hp sump pump draws about 700-900 W while pumping; run time varies hugely with groundwater, from near zero to several hours a day in spring.
Ways to cut either cost
Protects the basement during outages.
See options on AmazonDiverting roof water away cuts how often the pump runs.
See options on AmazonMoves the same air with a fraction of the power of rotary vane compressors.
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Frequently asked questions
Which costs more to run, a septic aerator or a sump pump?
At typical use and the U.S. average rate (17.99¢/kWh), a septic aerator costs about $126 a year versus $16 for a sump pump. That's $110 more, or 8.0× as much.
How many watts do septic aerator and sump pump use?
A septic aerator typically draws 80 W (range 40–500 W). A sump pump draws 800 W (range 400–1,300 W). Watts alone don't decide cost. Hours of use, cycling and standby matter just as much.
Rates: EIA, 12 months ending 2026-07. Methodology.