One of the units was partially below grade, and water got in and ruined everything.  

Current useful life left for water heaters and furances ?

The boiler heats all 3 units and was reconditioned in 2014..the current seller/owner says that the monthly heat and water bills average out to about $250 a month over the course of the year. 

I understand that the streets are lower and you'd expect the water to go there first, but what I want to know is whether the home itself would be considered to be in that zone for insurance purposes.

Well water or oil heat can affect the property uses as wellI would want to know about enviro hazards, at least any they will fess up too.

What it does, is it allows you to add water right to the stove into the pans without transporting them from one place to another.

They did, but of course they didn't clean the place when they left, and they flushed a washcloth down the toilet and we ended up paying the week's worth of water/sewer.Anyway....a bad vibe at this point won't likely get better.

But the past 2 yrs I have had some blips in the water.

We were hampered by the lack of electricity and water.

As @Karen Margrave mentioned, there's a ton of details related to the zoning and topography - principally whether the lot is level and graded yet or not, as well as whether there's water meter(s) and such already in place - that have big impacts on your costs and hold time.