Sewer gas Sewer gas Sewer gas is a complex mixture of toxic and nontoxic gases produced and collected in sewage systems by the decomposition of organic household or industrial wastes, typical components of sewage. Sewer gases may include hydrogen sulfide, ammonia, methane, esters, carbon monoxide, sulfur dioxide and nitrogen oxides. Improper disposal of petroleum products such as gasoline and mineral spirits contribute to sewer gas hazards. Sewer gases are of concern due to their odor, health effects, and potential for creating fire or explosions. Sewer gas is typically restricted from entering buildings through plumbing traps that create a water seal at potential
Merrimack Valley gas explosions its buildings temporarily. Schools and state offices in the three communities remained closed the following day. First responders from as far away as Boston and Manchester, New Hampshire rushed to Lawrence, Andover, and North Andover as gas and electric lines were shut off to prevent further explosions. The NTSB also sent a team to investigate the situation the following day stating that they were going to look at the design of the pipeline system, maintenance associated with it, the emergency response, and the integrity management system of Columbia Gas. The gas company involved released several updates about the fires and