Sewer appurtenances: Identify the incorrect statement regarding manholes, catch basins, and inlets in sewer systems.

Introduction / Context:

Sewer networks include several appurtenances—manholes for access, catch basins and inlets for street drainage interception. Understanding their correct placement helps ensure functionality and ease of maintenance.

Given Data / Assumptions:

• Combined versus separate sewer systems have different inlet strategies.
• Manholes are routine access points.
• Catch basins separate grit/debris from roadway runoff before entering storm sewers.

Concept / Approach:

It is incorrect to claim that inlets are provided in all sewers. Inlets are features of stormwater collection along curbs and streets; they are not required on sanitary-only sewers that receive flows from building laterals rather than street runoff.

Step-by-Step Solution:

Verification / Alternative check:

Separate sanitary systems have no street inlets by design; thus the statement claiming universality is false.

Why Other Options Are Wrong:

• Manhole statements are true and standard practice.
• None of these is wrong because one statement is indeed incorrect.

Common Pitfalls:

• Confusing combined systems (which may have inlets) with sanitary-only systems.

Final Answer:

Inlets are generally provided in all sewers regardless of type and location