However, there is an operating gas station across the street that has an underground "plume" that affects the dirt underneath the subject pad.

And its a huge difference of having a primary and or rentals in regards to living in CA and having rentals in Tx double whammy on tax's and the other issues in Texas which is weather  and soil issues for foundations.

The soil around your house should always be dry when you take out a scoop with a shovel.

Hiding money like a lover's soiled blue dress would be dishonest.

Given this has been a salvage yard for 65 plus years I know that there will be soil contamination from the previous owners.

They've already done soil testing in several areas and no contamination has ever been found.

As others have said, request a walk-through with the landlord prior to move-out.Commonly overlooked spots: damage behind doors, kitchen cupboards not wiped clean and occasionally items left in the deep reaches of the cupboards, refrigerator seal folds not clean, window tracks not clean, stove top dirty underneath (most lift up), range bottom drawer dirty and/or items left inside, door stoppers missing, loose towel rods, dusty light fixtures, plumbing fixtures not entirely clean, outside lights and mailbox dirty, tops of door trim and tops of baseboard dirty, light switches dirty, refrigerator drip pan dirty and back of refrigerator dusty.BTW, to clean the range burner bowls, soak them overnight in ammonia and then scrub.

I prefer a house without carpet but I'll still buy one that has it since the cost to replace it with laminate or paint the hardwood underneath is pretty low and requires less maintenanceI will usually leave the carpet there until it is destroyed which is usually after 1 or 2 tenants

Fortunately, the place was habitable and sanitary since there was concrete underneath so I had the right to continue charging rent.

@Jerry K.Thanks for sharing. invest in raw land has so much opportunities if you know what to look for the different components, like soil, vegetation , mineral rights, water source...etc.In your case is the billboard.