Which Chemical Is Cited for Disinfection and Odor Control in Sewer Systems?

• A. Ammonia
• B. Ozone
• C. Hydrogen Peroxide
• D. Chlorine

Answer: (D)

Disinfection in sewer systems relies on a chemical that both inactivates pathogens and provides a residual to keep downstream areas protected, while also helping to curb odors. Chlorine does this well: it effectively kills a broad range of microorganisms and leaves a residual disinfectant in the line to maintain protection further along the system. It also oxidizes odor-causing compounds like hydrogen sulfide, which reduces bad smells in the sewer. Ammonia by itself isn’t a disinfectant and can contribute to odors; ozone is a strong disinfectant but is expensive and less practical for large sewer networks; hydrogen peroxide can oxidize some odors but doesn’t leave a lasting residual and is not typically economical for widespread use in sewer mains. So chlorine is the best option for both disinfection and odor control in sewer systems.