What is the maximum developed length between underground cleanouts for piping greater than 2 inches?

• A. 40 feet
• B. 75 feet
• C. 100 feet
• D. 60 feet

Answer: (B)

Access to the line for clearing obstructions is the key idea. Cleanouts must be spaced so that any point on a horizontal run can be reached from a cleanout with standard rodding or snaking equipment. For piping larger than 2 inches, the practical limit is 75 feet between cleanouts. This keeps obstruction clearing feasible from an access point without needing excessive digging or long, hard-to-reach runs. If a straight run would exceed that distance, add another cleanout so no segment is longer than about 75 feet. Cleanouts are also placed at changes in direction and at the end of a run, so plan spacing to satisfy both the 75-foot limit and those other access points.