If a lender is involved, they may insist on your doing environmental testing & remedial work in compliance with current codes & environmental regulations. Remedial work done in the 1970s may not comply with current standards. Be sure to specify in the contract that your buyer be allowed time to conduct environmental testing by a licensed specialist. (Some states specify the remedial work plans be approved by state regulatory agencies.)
Because of govt. bureaucracy, this testing & regulatory approval may be a lengthy process. I know because I'm currently selling a commercial building I own. The buyer is getting a small business administration loan, which requires environmental testing.
If your buyer is paying cash, he won't have to go through the EPA red tape. He might want environmental testing for his own information. However, he might get the property at a much lower price if he accepts it "as is" & conducts the inspections later. Be sure to get a "hold harmless" contact signed in this case.
Marcia Kelly, CRS
Keller Williams, Legacy Partners