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 fires were reported over a very short period of time in the towns of Lawrence, Andover, and North Andover beginning about 4:15pm (EDT). Through the evening emergency crews responded to between 40 and 80 fires. At one time, as many as 18 fires were burning at once, and Andover officials struck a maximum 10-alarm response. Andover's fire chief described "billows of smoke coming from Lawrence behind me, I could see plumes of smoke in front of me within the town of Andover, it just looked like an absolute war zone." A Lawrence resident described finding his boiler on fire after