At my shop I tell friends and neighbors to drop old washers , refrigerators , any metal .

Would we have sold California to Japan and Florida to Saudi Arabia for a few bricks of shiny yellow metal?

They recently bought the old metal recycling center as well as other lots in the area. 

You can also use an antioxidant compound, which is a metallic substance on all your aluminum wire connections.

I belong to several forums, coin collecting, metal detecting, online gaming, precious metal detecting, etc.... and whenever I ask a question, I get a courteous and helpful answer.Let me add this.

Now, if they will drive in a few metal posts with some wire fencing that can be taken down when they leave, that might be a solution.

The way it was explained to me about water quality was if there was a possibility of corrosion then use the plastic fittings vs the metal which is what we do here in the Texas hill country.

I wouldn't worry about it.The only way to "prevent" termites is during original construction, use metal studs, apply a layer of termite barrier before the slab pour etc...If he is recommending an annual treatment, then it must be subterranean termites he is referring to. 

I've always liked the idea along with pre-fab metal stud apartments. 

Landlord didnt want to fix the ac unit because the previous tenants dog messed up the outer AC unit and the coils are open and in sight.