A proper sewer tap enters the public sewer main at about which position?

• A. Below the flow line of the main
• B. At about a 10 o'clock or 2 o'clock position
• C. At a 90 degree angle off the horizontal
• D. At the top dead center of the main

Answer: (B)

A sewer service lateral should enter the public main on the upper side of the pipe, roughly at the 10 o’clock or 2 o’clock position. Placing the tap here keeps the connection above the main’s centerline, away from settled solids at the bottom, and allows the service line to join the main at a favorable angle for gravity flow. This reduces the chance of blockages at the connection and helps prevent backflow or air/flow disruption in the service line.

Taps made low on the main, directly at the bottom, or at awkward orientations (like a straight perpendicular entry or the very top center) can lead to solids bridging, blockages, or difficult installation, which is why those positions are not preferred.