Why should groundwater from leaking gasoline tank cleanup projects be treated before discharge?

The appropriate reasoning for treating groundwater from leaking gasoline tank cleanup projects before discharge is primarily centered on environmental protection and infrastructure integrity. When groundwater is contaminated with petroleum products, it can lead to significant challenges if released directly into sewers or surface waters without treatment.

Treating this groundwater helps to clear the pollutants that could potentially lead to hydraulic capacity issues within the sewer system. Excessive pollutants can cause blockages or reduce the overall efficiency of the sewer treatment process. Therefore, the objective of treatment is to ensure that any contaminants are adequately removed, thus maintaining the functionality of the sewer system and preventing overflow or other operational challenges.

In the context of the other choices, enhancing appearance or reducing treatment costs is not a justifiable reason for treating contaminated groundwater, as these do not directly relate to protecting public health or the environment. Similarly, capturing more pollutants is important but is more of a secondary benefit rather than the primary reason for treating groundwater from these cleanup efforts. The focus is on the potential negative impacts on the sewer systems, making the need for treatment before discharge critical to environmental compliance and public safety.