Heating oil dealers are prohibited from filling a tank if it fails to meet the following five minimum standards:

1) The tank must be on a stable foundation.
2) It must have a working vent alarm (whistle).
3) Both the fill pipe and the vent pipe must have a minimum diameter of 1-1/4 inch.
4) If below grade or buried in concrete, the fuel line between the tank and the burner must be either plastic coated copper or sleeved.
5) A fuel oil tank can not have leaks, drips, pitting, rust, dents, cracks or corrosion.

More Information:

Aboveground Vermont Storage Tank Rules
Underground Vermont Storage Tank Rules

Note:
The above information was gathered from the Vermont Fuel Dealers Association and the Vermont Agency of Natural Resources.