What should I consider when using a sewage ejector pump?
From this article http://burnettplumbing.com/tenways/; Step #6 talks about a sewage ejector pump:


  If you have a sewage ejector pump in your basement, plan for the fact that it will eventually fail.
  These pumps operate in a very harsh
  environment (submersed in sewage) and
  often fail after just a few years.
  Failure of your pump could mean sewage
  back-up in your basement. The risk of
  a damaging back-up is especially high
  if you have a water softener which
  drains into the sewage ejector system.
  If the softener regenerates while the
  ejector pump is not functioning, you
  could end up with up to 100 gallons of
  sewage backing up through the floor
  drain. All of this could happen at
  night while you are asleep, that is
  when most softeners regenerate.
  Consider installing an alarm in your
  sewage ejector tank. An alarm is
  designed to buzz loudly in the event
  of pump failure. Assuming you're home
  when this occurs, you should have
  ample time to shut-off your water
  before the sewage reaches flood level.
  Remember, alarms can fail too! It is
  best to NOT store valuable items on
  the basement floor if they could be
  damaged by water or sewage flooding.