@Mario Morales  If it is an older machine check that it is functioning properly and if it has any leaks particularly check the hose connections when running.  

That said, you do have more tangible damages: the drainage system, the septic area (if impacted), and the mailbox.

What are other investors in the area paying annually per unit in insurance (approx range) and water + sewer + trash?

Specifically:What were your biggest challenges (zoning, drainage, ventilation, fire code, utilities, tenant improvements)?

From there, get ready to drink from a fire hose.

If there isn't proper water drainage, the water can wash away or erode the foundation.

At the same time, new city-level regulations—like the recent ordinance aimed at controlling water usage by large developments—signal growing attention to sustainability and could affect future commercial and industrial real estate projects.

As far as any liabilities I could see, there is a small pond at the front of the property, but doesn't seem to have any water or to deep, but sure makes me uneasy if the tenants had small kids. 

I've seen them hooked up wrong with water leaking, dryer hoses not attached to the vent and just blowing lint into the house, abandoned dead appliances when they move out, bashed up walls and floors from them trying to move them in and out on their own, etc.

At minimum you’ll need an architect (to design plans that meet code), a general contractor (to build), and potentially a civil engineer (if there’s grading, utilities, or drainage work).