I was wondering if anybody knew any state or local laws about remediation of abandoned underground tanks that are not used anymore on ones property.

Meaning, How fast can you consistently respond and remedy a guest/client emergency?

Separate two things: possible compensation for her increased costs/damages due to your failure to deliver and he request demand for further compensation.Your lease should say something like “return of deposit is only remedy for failure to deliver”.

Also with the data - can the govt abstract the data to determine a remedy to limit damage ?

@Brian Antonucci  yes, I walk through the unit before move out to give them a chance to remedy items before I withhold deposit. 

This includes fire or electrical hazards, plumbing issues that can result in a lack of hot water or water damage, lack of heat, lead paint remediation, etc.

Already capital for acquisition is drying up, now all that has to happen is accentuate the problem so there is a form of mass tenant rent defaults and as groundwork is in place for no remedy for landlords, thus a financial catastrophe situation.

If the vapor is coming from the soil, wouldn't the proper way to remedy the situation involve actual soil removal/clean up?

You want to avoid a lawsuit, and a demand letter shows you mean business but concurrently allows the seller an opportunity to remedy the problem before it escalates.  

The geologist and toxicologist hired by the plant for ground and air sampling has assured me that the property is not in the contaminated area (I have these contacts because my current residence a block over has vapors coming in through the foundation and remediation in progress).