Sorry you didn't get a response the 1st time. Usually, it's fair to assume that you didn't get a response because 1) no one has an answer, or 2) no one can answer your question. BUT, I'll try.
You mention sump pump, city water, and septic tank. None of these services are 'connected' to the other. If the sump pump alarm is sounding, it may mean the water is rising to a point where it's about to over-flow the pit, and yet, the pump hasn't come one. There should be a manual switch to 'flush out' the pit. If this works, the motor should be ok. The only other part that might have a problem, that I'm aware of, is the float switch. If it's STUCK in the DOWN position, the water can rise as high as it wants and eventually triggers the high-water-alarm. I don't know if you can simply 'clean' the float mechanism or if you need to have it replaced.
If you don't have an Owner's Manual, maybe a neighbor has one. (Perhaps you're not the only resident that has a pump on your street.) Otherwise, search the WEB or call the mfgr. that's listed on the pump. Any Plumbing Supply House should be able to help you, directly OR indirectly. Write down whatever info you can and bring it into their House. Other than this, your problem is out of my league.