Which of the following describes problems that can result when sewage goes septic?

• A. Horrid smell; produces sulfur compounds; corrosion of pipes due to acid production
• B. Horrid smell only
• C. Hydrogen sulfide produced only
• D. Corrosion only

Answer: (A)

Septic sewer conditions arise from anaerobic digestion, which produces hydrogen sulfide and other sulfur compounds. Hydrogen sulfide is the rotten-egg smelling gas, so the odor is a direct sign of these sulfur compounds released as sewage breaks down. Those sulfur compounds can react further in the sewer environment, and hydrogen sulfide can be oxidized to sulfuric acid by bacteria, which attacks pipes and fixtures. That combination—strong odor from sulfur compounds plus the potential for corrosion due to acid production—best describes the problems you’d see. The other descriptions only cover one aspect (odor or a single compound) and don’t capture the full range of issues that septic sewage can cause.