Hierarchy of sewerage network: In a conventional system, from which component does the sewerage network originate (i.e., where does collection begin)?

Introduction / Context:
Sewer networks are hierarchical. Knowing the correct order—from building connections to final outfall—helps in layout, capacity checks, and maintenance planning.

Given Data / Assumptions:

• Standard municipal sewerage hierarchy.
• Collection starts at individual properties.

Concept / Approach:
The system begins with house sewers (building laterals) that carry wastewater from fixtures to the public right-of-way. These discharge into small branch or lateral sewers, then into mains, then trunks/interceptors, and finally to the outfall sewer conveying to treatment.

Step-by-Step Solution:
1) Identify smallest element collecting flow: house sewer (building lateral).2) Flow path: house sewer → branch/lateral → main → trunk/interceptor → outfall to treatment.3) Therefore, the origin of the network is the house sewer.

Verification / Alternative check:
Typical standards and textbooks illustrate this sequence; no exceptions in conventional systems.

Why Other Options Are Wrong:
Branch/Main/Outfall/Trunk: These are progressively downstream components and do not represent the system origin at the parcel level.

Common Pitfalls:

• Confusing “lateral” (public) with “house sewer” (private); terminology varies, but the house connection is the source.

Final Answer:
House sewers (building laterals)