Contaminated soil, lead based paint is still used commercially, just not residentially, high levels of radiation, mold, asbestos. 

Dry cleaners use some nasty chemicals and if any of that contaminated the ground you will be on the hook for it. 

Found this in My Texas Real Estate Principle 2 Book"TMARR requires that all persons who conduct assessment and remediation of mold be properly trained and licensed by the state.Under the rules, a person is not required to be licensed to perform mold remediation in an area in which the mold contamination affects a total surface area of less than 25 contiguous square feet.

You could go to the property and find that some crack head was cooking in a vacant unit, after a near miss with death and the police leaving, you could get a letter in a couple days from the city condeming the property due to contamination by the crack head.

This will avoid contaminating all of your businesses with "dealer status".Dealer status may also apply to operating as a sole proprietorship (buying/selling in your personal name), so be careful and get expert tax advice.I am not a lawyer or accountant, so ignore everything I just said and get your own professional advisor.

If you're going to spring a claim of a environmental contamination on the seller, you're going to have to, IMHO, provide some sort of third party validation to support the claim.

I found out that in the 80's, that site contained a small gas station which had a contamination issue. 

Eric,Unless there was a leak or contamination the EPA would not be involved and there would not be a need for a NFA  letter.

And since this property was across the street from a very prominent destination lake, governmental action would be swift and strong should any environmental contamination issues come up in the future to protect the lake. 

I don't mean to insult you and respect your decision, but you do know that that CDC has yet to trace a single transmission of COVID-19 to touching a contaminated surface, I assume?