If you suspect an underground fuel tank that is no longer in use exists you must take action before you purchase the home. State regulations generally require the proper abandonment or removal of underground fuel storage tanks that are no longer in use. The existence of the tank must be verified and addressed prior to expiration of your inspection contingency. Discuss the implications of such a tank with your Attorney. In New Jersey the Department of Community Affairs, Construction Code Element, CN 816, Trenton, NJ 08625-0816 (609) 984-3156. DCA Bulletins 95-1B & 95-1D provide information that may pertain to this situation.
If heating fuels have been changed, the chimney must be cleaned (to determine if damage to the chimney interior has occurred), inspected and repaired or lined if necessary by a chimney sweep prior to expiration of your inspection contingency to avoid a potentially hazardous condition. The result of not having a safe chimeny can be fatal!