What can sewer gas contain?

Sewer gas is a complex mixture of various gases that can arise from the decomposition of organic matter in sewage systems. Among the components it may contain are hydrogen sulfide (H2S), methane, and potentially chlorine, though chlorine is more commonly associated with wastewater treatment processes rather than sewer gas itself.

Hydrogen sulfide (H2S) is notable for its characteristic rotten egg smell and is a toxic gas that can be harmful at elevated concentrations. Methane is a flammable gas and is produced during anaerobic decomposition, commonly found in sewer systems where organic material breaks down without oxygen. Chlorine can be present if chlorine products are used for disinfection in the treatment of sewage or as a byproduct of reactions occurring in the system.

The presence of these gases underscores the importance of proper ventilation and safety measures in areas where sewer gas might accumulate. The inclusion of all these components indicates a comprehensive understanding of what can potentially be found in sewer gas, affirming the correctness of the answer that encompasses them all.