It's been raining pretty hard in my area. Until yesterday, I could still hear my sump pump discharging water outside. The rain has stopped 2 days ago so I have not heard the sump pump working. Yesterday, there's a humming "Bbbrrrr" noise coming from the basement. At first, I thought it was the sump pump. When I came down to inspect, what making the noise was next to the sump pump and looked like a sump pump, only the lid is screwed shut.

After some Googling, I think the noise maker is called 'ejector pump'. However, what I read about ejector pump doesn't make sense. I have a toilet and shower in the basement but they have not been used for at least 6 months. Could my ejector pump be making humming noise if there has been no water usage in the basement. There are 2 white PVC pipes connected to the ejector pump. When I touched one of the white PVC pipe connected to the ejector pump, I can feel it's humming and vibrating. The other PVC pipe is completely silent.

Is what I've described an ejector pump? What should be my next step?

Something is triggering it, and that's normal. This site may help explain it.

Sumps Pumps vs. Ejector Pumps (http://www.uswaterproofing.com/learning-center/sump-pump-vs.-ejector-pump-whats-the-difference)

So let me ask if you have a sink, or washer and dryer in your basement?

If your answer is no, then maybe you have a main drain back up that is actuating the pump. Very possible that it's time for some simple maintenance. At the very least it should be checked out. Go here,

https://theplumbinginfo.com/troubleshooting-ejector-pump/

Also read the comments at the end of the article. Very informative. Please let us know what you find.

With 2 pipes that is an ejector pump. I'm wondering if there may be some ground water getting in the tank, causing it to run.

Is that humming noise continuous ? Did you try to turn the pump OFF and back ON ? When was the last time you cleaned the Sewer Ejector pit ?

Sewer Ejector humming noise usually means there is most-likely some debris lodged in the rotor, or pump itself is going bad. I suggest you turn off electrical breaker, open the lid, and clean the pump intake area and rotors. Run few cycles with clean water from the hose before you reinstall the lid, making sure pump runs as it should. Also, elevate the pump by setting it on bricks. That will keep it from sucking debris from the bottom of the pit


As far as "where is the water coming from" - Toilet bowl may have a small leak that keeps filling up sewer ejector. Also, your check valve may be bad, letting water into Sewer Ejector

Hope that helps

Milo