What if the guests at their place figure out the "Environmental issue with their house"?

We have a mobile home park under contract in North Carolina and are seeking referrals to an environmental attorney who can help us assess the risk associated with acquiring a park with a contaminated water well. 

I would guess you would have to put a little money up in escrow that was refundable, then you could go through your everything you need to do but i don't know where you are going to get the money for everything else like plans engineering pre app with city phase 1 environmental.

A lender will require a appraisal, environmental phase 1, and a professional property inspection.

I am not familiar with the price of the relocation, but I have experience relocating them as an environmental scientist for a consulting firm. 

Any lead paint / asbestos / environmental issues?

But the land we bought for our neighborhood development has been a gigantic learning curve regarding what the city council, architectural review board, department of environmental management, and other agencies will require you to comply with.

There's even an anti-wealth sentiment among many, who portray it as "consumerism" or anti-environmental.

Due to environmental concerns, (nitrates, nitrites) and new developments that "don't want to be next to a trailer park" (although they built and bought next to your park) Health Departments in many municipalities are NOT renewing permits.  

He will lose some of his bid amount, but thats better than keeping a property with some major issues (structural, or environmental) .