Why are gasoline and volatile solvents deemed objectionable in a sewer?

Gasoline and volatile solvents are considered objectionable in a sewer primarily due to their potential to produce an explosion hazard. These substances are highly flammable and can create explosive atmospheres, especially in confined spaces such as sewer lines. When mixed with air, the vapors from these solvents can reach combustible concentrations, posing a significant risk to both safety and infrastructure.

The presence of such volatile materials can lead to dangerous situations, not only for sewer maintenance workers but also for the general public. In addition, when these substances enter the wastewater treatment process, they can interfere with the biological processes used for sewage treatment, further exacerbating safety concerns.

While other factors like corrosion of sewer materials, creation of offensive odors, and alteration of sewage composition are also important considerations (with potential implications for sewer system integrity and environmental impact), the immediate threat that gasoline and volatile solvents pose through their flammable nature and potential for explosion is the most significant reason for their objectionability in sewer systems.