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.       

Many areas are updating their regulations because septic systems are at best rudimentary treatment systems and in areas of high concentration (>1 system per 5 acres) and high ground water, they are not adequate.

I have done countless environmental surveys at countless gas stations in my five years in this profession, and I would never ever purchase a station due to the emense cost/ liability (when contaminants end up in someone elses ground water supply) of remediation.

You can also call Southwest Groundwater Surveys (800-394-6207) and schedule a sonar test to get a more accurate quote.

"The Torrance refinery has allowed contaminated groundwater beneath surrounding residential properties to “store toxic chemicals” emanating from the plant for years, a hydrologist and Cal State Fullerton professor testified in a Los Angeles Superior Court lawsuit."