Well pump vs. septic aerator: running cost
A well pump is cheaper to run: about $92 a year versus $126 for a septic aerator at typical use and 17.99¢/kWh, a $34 difference.
| Well pump | Septic aerator | |
|---|---|---|
| Typical watts | 1,400 W | 80 W |
| Watt range | 800–2,500 W | 40–500 W |
| Typical use | 1 hour a day | 24 hours a day |
| Energy per year | 511 kWh | 701 kWh |
| Cost per hour | 25¢ | 1.4¢ |
| Cost per day | 25¢ | 35¢ |
| Cost per month | $7.67 | $10.51 |
| Cost per year | $92 | $126 |
| Per year in Hawaii (43.51¢) | $222 | $305 |
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What drives the difference
- Well pump: A 3/4 hp submersible well pump draws about 1,200-1,500 W; a household using 300 gallons a day at 8-10 gpm runs it about 30-60 minutes a day, or roughly 400-700 kWh a year.
- 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.
Ways to cut either cost
Fewer, longer pump cycles reduce start-up energy and wear.
See options on AmazonSupplies garden water without running the well pump.
See options on AmazonMoves the same air with a fraction of the power of rotary vane compressors.
See options on AmazonWe may earn a commission from qualifying purchases. It never changes the numbers we show. Disclosure.
Frequently asked questions
Which costs more to run, a well pump or a septic aerator?
At typical use and the U.S. average rate (17.99¢/kWh), a septic aerator costs about $126 a year versus $92 for a well pump. That's $34 more, or 1.4× as much.
How many watts do well pump and septic aerator use?
A well pump typically draws 1,400 W (range 800–2,500 W). A septic aerator draws 80 W (range 40–500 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.