Propane or Mains

Mains gas

A buried service line runs from the main in the street to a meter. Under 49 CFR § 192.3 the regulated service line ends at the meter outlet. There is a utility, there is a tariff, and there is somebody to call about the part they are responsible for.

Source: 49 CFR § 192.3, via PHMSA interpretation PI-12-0003.

Propane

A tank on the property, a regulator, and a buried run to the house. There is no service line in the federal sense and no meter boundary: the installation is the property owner’s, and the supplier’s role is whatever your contract with them says.

That is the practical difference. On mains, part of the problem belongs to somebody else. On propane, none of it does.

What changes about the risk

Propane is heavier than air and collects in low spaces — basements, pits, crawl spaces — rather than dispersing upward. It is odorized like natural gas, and the emergency response is identical: leave on foot, no phones or switches inside, call 911 from elsewhere.

And what stays the same

Everything about digging. A buried propane line is buried line, the free call before excavation applies, and a privately owned run is exactly the sort that may not be covered by a standard locate.

Source: PHMSA, 811 Day.

Which one is more common where you are

It varies enormously by town rather than by state, which is why every town page on this site carries its own split rather than inheriting one. Some towns we cover are almost entirely on mains; in others most gas-heated homes are on a tank.