There are no town or state laws that prohibit selling a house that has a working underground fuel tank.
Many of the issues dealing with underground tanks are driven by the marketplace and mortgage industry. It is getting progressively more difficult to obtain a mortgage for homes with underground tanks due to the possibility of leaking and environmental damage. Most people today tend to remove the underground tank prior to the sale of the home.
The Building Department does require a permit to remove underground tanks and to replace them with new tanks. This will provide independent documentation in the future that the tank or tanks were removed. The Building Department does not keep soil reports or other documentation of contamination.