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
Submarine mines in United States harbor defense these mine control panels, plus many more related rack-mount devices for controlling the casemate's generators, inverters, and battery systems. The mines could be fired in three ways, listed here in order of tactical preference: Delayed contact fire was preferred because it was thought that the mine would first be dragged underneath the target and then fired after a few seconds' delay, once it had had the chance to contact a more lightly protected portion of the target's bottom. This type of fire required the casemate troops to hear the bell and see the accompanying signal light that indicated when a