All vent and branch lines shall be installed so that they drain where?

• A. Soil or Waste Pipe
• B. Roof Drain
• C. Into the Ground
• D. Into the Building Interior

Answer: (A)

The important idea is that vent and branch lines are part of the building’s drainage system and must connect to the soil or waste pipe that leads to the sewer or septic system. This arrangement keeps wastewater moving along the proper path and lets vents admit air to prevent traps from being siphoned dry, preserving proper drainage and odor control. Draining into a roof drain, into the ground, or into the building interior would bypass the intended drainage system and create sanitation issues, odors, or flooding. So the correct route is into the soil or waste pipe.