What is a common result of improperly maintained sewer systems?

Improperly maintained sewer systems often lead to sewage overflows. This phenomenon occurs because accumulated debris, grease, and other blockages can restrict flow within the pipes. When the system cannot accommodate the normal volume of sewage due to these constraints, it can cause backups and ultimately overflow at manholes or through the system itself.

Sewage overflows pose serious environmental and public health risks, as they can contaminate water sources and negatively impact surrounding communities. Adequate maintenance — including regular inspections and cleaning of sewer lines — is essential to prevent blockages and ensure the efficient operation of the collection systems.

The other choices represent situations typically associated with properly maintained systems or are not direct results of neglect. Regular maintenance checks are essential for avoiding issues, and decreased flow rates can be a sign of issues but are not as direct a consequence as overflows. Noticing fewer mechanical failures would generally reflect a well-maintained system, whereas neglect leads to more issues. Thus, the consequences of poor maintenance directly relate to sewage overflows as the most critical outcome.