Where are manholes typically installed?

• A. Along Straight Runs Only
• B. At Every Sewer Line Segment
• C. At Pipe Alignment Changes, Grade Changes, Pipe Material Changes, Wastewater Intersections, and Line Ends
• D. In Low-Occupancy Areas Only

Answer: (C)

Manholes are built to give access to sewer lines for cleaning, inspection, and maintenance at points where the system changes or needs a junction. The best choice places them at pipe alignment changes (where the route turns), grade changes (where the slope or vertical position shifts), pipe material changes (where different pipe sections connect), wastewater intersections (where lines meet or branch), and line ends (terminations). These locations are where problems are most likely to occur or where access is essential for joining, inspecting, or servicing the network. The other options are not correct because placing manholes only along straight runs, at every sewer line segment, or only in low-occupancy areas would create unnecessary cost or fail to provide needed access at critical transition points.