1 - yes2 - I don't think that the drain from your house to the main sewer falls under the "Municipal Sewer" category that @Joshua Thompson mentioned, but I would have to check before giving a verdict.

Putting value add on top of that can be a great way to build a passive portfolio that doesn't drain your will to live.

But understand the type of risk could be the exiting tenant having poured cement down the drains, no appliances, no cabinets, a leaking roofs with mold inside the house, no AC,  or squatters having lived in the house with untold 'grossness' being left behind for you.  

Our intent was to sell, but we are not having luck and need to move in another direction, carrying costs are draining us. 

I recommend this option, as just sitting on the property with no income is a drain on you both financially and mentally. 

I've had to do some work to the property (drain tile in basements, insurance claim for plumbing issue) but I knew that things like this would happen and I could stomach these expenses with my W-2 income. 

The county may want one master drain field with an established Alt. field if the first one fails. etc etc.. its very county specific so thats where I would start.. 

These properties are just going down the drain and bringing the neighborhood with it.

Hopefully it’s just issues with your drain piping, which is a quick fix.

It could be illegal to drain them onto the ground so I would check.