@JBush Jack @Marvel_Equity has good advice - a Park like this is really about risk tolerance and diligence. There is absolutely a larger buyer pool for Parks on public utilities.
But on the flip side there is likely recovery on these utilities the current owner is not recognizing. I don't know about Michigan specifically, but in Texas you can setup a utility or MUD district to recover your expenses for regular maintenance costs associated with the wells and septic. It's not a quick process and takes ~6 months to get setup before the first bill can legally go to the tenants, but to be fair it's not really a complicated process. It just takes government a long time to turn around paperwork.
With the increased diligence, increased management, and increased risks doing a deal like this would be a problem for most, but once it's up and running and full would be a nice little investment property. If you're trying to quickly buy a property and flip it after doing some simple expense management and revenue tweaks this would probably not be my first choice. This is long term buy and hold IMHO. Maybe city utilities are 5 years away from being at the street.
That septic sizing really sticks out like a sore thumb to me (not necessarily bad, just not as common in MHPs), maybe @PhillipMerrill can steer you better on it.