I have a friend who bragged that after he installs solar panels his utility cost will be zero. (he forgot about phone/internet) Assume for a moment that is true for electricity (including his well pump and geothermal heat pump). I mentioned that since he is not on city sewer he has to pay for periodic septic tank cleanouts but he said that he didn’t consider that a utility cost.
While it is not a utility in the Public Utility sense, it is a cost to him for a service (sewage disposal) that is often provided by utilities.
It doesn’t require a permanent connection to an outside service so I wouldn’t call it a utility. There may be legal precedent on the meaning of ‘utility’ when it comes to lease and rental agreements. If a lease indicated a renter was responsible for utilities I’m not sure that would be interpreted to mean septic system maintenance.
If you heat with propane, is that a utility cost? (I’d lean towards yes)
But I would not count replacing the well pump – even though that is a cost related to a service that is often provided by utilities (water).