I've found lots of trash, grow lights in attics and of course lots of paint it seams like every house I get has a paint collection and yard chemicals and I have a shelf in my office that is covered with little tokens I found over the years every thing from coins to old cast iron toys. still waiting to find the pot of gold :)

I had another house with chemical drums in the backyard, got it real cheap.

I went back to school to become a chemical engineer and worked in that field for nearly 8 years.

I'm a 30 year old chemical engineer with a steady job and generous income. 

You can sand it or go "passive/chemical. 

I have seen pictures of the inside but I don't know if any chemicals seeped through the walls.

Tenant agrees not to use caustic drain cleaning chemicals in any of the drains or plumbing fixtures.

My understanding is that the EPA is beginning to ratchet up additional testing for more chemicals and certain states, and that testing of these will initially be more expensive.  

Cleaning grease is a lot harder than I thought, special chemicals still require multiple cleanings...Moving the fridge was an eye opener as the floor was filthy with food grease and mouse droppings they chose not to clean. 

Things like old ovens, random chemical waste, excess trash left behind by a tenant, etc.I used to drive a sedan and I was able to make that work, but having a truck is just a bit easier, in my opinion.