I was wrong, its main purpose was to remove ground water. 

In rural areas, without a quality ground water supply, water is a huge barrier to development.

About halfway down the hill, ground water would come out and make the sidewalk and stairs slippery.

. § 66-5-212(c) as "a subterranean void created by the dissolution of limestone or dolostone strata resulting from groundwater erosion, causing a surface subsidence of soil, sediment, or rock and is indicated through the contour lines on the Property's recorded plat map."

I'm considering converting my basement into a short-term rental as a house-hack and curious to hear perspectives on this endeavor and if you have any contractor recommendations.Here's some background info:- I live behind a major university- AirDNA has favorable occupancy in this area (~79%)- Basement is a walk-out with it's own entrance and already has an in-ground water hook-upThanks in advance for your help!

Unsure of exact details but it had issues with gas station cleanup due to minimum ppm for ground water/gas.

So I speak from experience.Pay close attention the foundation as that can be a major cost if compromised especially if it is in an area where sink holes or ground water has been a problem. 

If there is contamination that has impacted groundwater or migrated off-site... you will get a letter from the NJDEP letting you know that you're responsible.  

If there is city water at the property the water in the house isn't contaminated, but it doesn't change the issue that this oil is leaking into the ground water which is going to leak in the other sources.

However, in the late 60's there was a MAJOR train derailment there and it took 52 years for the final cleanup of the benzene in the groundwater.