Issue possible grinder pump??

We bought our house 4 months ago. The house is a few years old but we are the only occupants to have lived in the home, the original builder had financial issues and had to sell to other contractor to finish house. Anyway when we bought the house we noticed a concrete lid with metal handle in the yard not far from the house. We asked realtor about it and was told it was city sewer pump access. As first time home buyers we did not question this. Well we just noticed that there was water on top of this lid and upon further inspection it definitely smells like sewer and is leaking from around the lid into our side yard. I asked a friend to come and look at it. He lifted up lid and it is definitely sewer and the water is at ground level. Said it looks like a grinder pump, the well is very deep and clearly the pump isn't working. Also said he has put in a few in the past but has not seen one in our town before and that it looks to be pretty rudimentary, and sketchy. Also said it should have had an alarm to let us know water level was getting high. My question is why would the builder have installed one in an area that they aren't normally installed, are there codes for these sort of things, shouldn't it have a more secure covering/marking/alarm and should it be failing after 4 months? And of course should the builder be liable for this? We have a standard builders warranty but does it cover things like this? Thank you.

As far as I know, these pumps are for either of two reasons.
1, there isn't enough slope to carry the waste to the sewer pipe,
2, the city requires sewage to be ground before depositing.

Were it the latter, other houses of the same vintage should have a grinder (sewage ejector) as well - but if it were a new regulation, other houses may be grandfathered in.

There is a distinct possibility the pump was stolen - they run about $1500 a piece. If stolen, the first thing the theif would do is disable the alarm so as not to alert you of his project.

I think you're simply going to have to pump it out - and old sump pump would be an easy way to go. Can't hurt to dump a gallon of bleach down there first.

Keep in mind the toilet paper may jam the pump.

Typically, the cover is screwed down in several places, as well as having mechanical clasps.