The odor also can be produced by sulfur bacteria or chemical reactions inside water heaters, or by pollution, which is probably the case, at least initially, with Sandy.
The rotten-egg smell does not mean your water is unsanitary, except in the rare case that the gas is caused by sewage pollution.
Hydrogen sulfide gas in the air can be harmful in high concentrations, Magnolia’s plumbers say.
When removing the gas from the water, which is possible, it’s important to vent the gas outside so it doesn’t collect in low-lying places like well pits, basements, or in enclosed areas like well houses.
How can you find the problem, and correct it? This is where calling your plumber becomes an important step.
If the rotten-egg smell only comes out of hot-water faucets, there’s probably a problem with the water heater.
If the smell is coming from both faucets, but only comes from water that has been treated by a water softener, the problem is most likely sulfur bacteria in the water softener.