He totally wants me to remove the portion about the property being "free from hazardous substances, and from violation of zoning, environmental, building, health or other govt codes or ordinances and that there is no material or other known defects or facts regarding the property that would adversely affect the value of the property."3. 

I prefer to not inherit other people's problems.Even if I was to give you a building for free, you'd still have to shell out money for inspection, environmental, due diligence, regulatory, lender and other reports (i.e. major $$$). 

There has been an environmental remediation company sent in to work on the spill (let’s just say it was almost 100 gallons, in order to keep this anonymous). 

There are just too many markets that I feel are too expensive, or the threat of environmental hazards would keep me up at night.

They may not allow it or might require an environmental impact study

Those types of buyers usually need longer timeframes to do soils, environmental, deal with planning/building dept/public works, etc, not to meeting survey, engineer, architect, etc.

You'll see that many parks were developed prior to the environmental regulations today, and I can't speak for everywhere, but in areas I'm familiar with the water/sewer/fire/road etc design standards make the site work costs too high to work for MHP typically. 

And lastly (well not lastly... just lastly for now)  phone append and email append the names and addresses to get methods of contact...If you really want to get crazy from that point, compare length of phone line ownership, and age of deed on the property to EPA minor environmental disaster maps and you can sort out who is old and probably has caner, pretty quickly. 

Any service or advertising contracts: (Trash, extermination, maintenance, management, commission agreements, union agreements, vending, billboard, pay telephone, etc. and any instrument or contract to be assumed by Purchaser) Copies of all recent appraisals, engineering reports, environmental reports Survey (as-built), legal description, architectural and engineering plans and specifications Payroll register: List of employees including name, position, wage rate, and entitled benefits Business license Physical inventory of furniture, fixtures, and equipment, and supplies.

Looking for environmental attorney who can provide legal advice to seller on seller's legal responsibility relating to ongoing cleanup of property.