Proposed Changes by Subject—National Plumbing Code 2025

National Plumbing Code 2025 (Proposed changes to 1 provision)

Drainage Systems

(Proposed changes to 1 provision)

Div.B 2.4.6.4. Protection from Backflow

2137 - Installation of a Backwater Valve for Plumbing Fixtures Located Below the Upstream Sanitary Manhole

Date modified:: 2026-04-24