Topics
Safety
Sewer gas, manholes, gas lines and cross bores. 6 items, each with key facts and sources.
- Sewer gas smell in the house: the usual causes
Most indoor sewer odors trace back to a trap that lost its water, a cap that is not tight, or a vent that cannot breathe. The checks, and the one case where you do not check at all.
- Hydrogen sulfide: why sewer gas can be dangerous
The rotten-egg gas in sewers pools low, burns, and shuts off the nose that would warn you. Federal exposure figures from ATSDR and OSHA, and what they mean around a house.
- Why no one should climb into a manhole or sewer pit
Sewer manholes can kill in minutes, and a large share of the dead are would-be rescuers. A 2010 New York case, the federal definitions, and what a homeowner should do instead.
- Cross bores: when a gas line runs through a sewer pipe
Trenchless boring can thread a new gas service straight through an unmarked sewer lateral. Utilities' own guidance on spotting one before a clog is cut, and what to do if gas escapes.
- Gas smell or sewer smell? If in doubt, treat it as gas
Natural gas is made to smell like rotten eggs, and so does sewer gas. The utilities' order of steps when you cannot tell them apart, and what to check only after the all-clear.
- Rotten-egg smell: sewer gas, natural gas or the water heater?
Three things smell like rotten eggs in an old house. One of them is an emergency, so the order of the checks matters.