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
1995 Daegu gas explosions Department Store chain, where 31 holes of 75 millimeter width that were going through a grout curtain were accidentally drilled through a city gas pipeline and resulted in gas leakages into the subway construction site through a nearby sewer lead to the explosion due to an unknown fire at the site. The explosion created a 50-meter pillar of fire. The accident killed 101 people, including 42 students, and injured 202. The 400-meter-long private parking lot on the construction site collapsed, and 60 buildings and 152 cars were damaged and the damage reached 54 billion won. The damage caused by the