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. 

I did that by going to a metal roofing supplier and asking them for a good local contractor.

Usually, code across the nation is to either notch posts for stringer support and/or utilize metal brackets were appropriate.

The contract itself states the following:"Specifications: Proposed CostRoofRemove & dispose of the existing roof, if additional layers are found they will be removed at $50.00/sq.Inspect current roof deck, if replacement is needed it will be completed at $1.65/s.f.Install 1⁄2” fiber board to the entire roof deck using screws and platesInstall .060 TPO to the roof with all needed flashings and trimsInstall perimeter metal with all needed flashingsProposed Cost: $3,300"I guess my question is, what options do I have at this point?