BCAB 1994 - Check valve requirement for a plastic water service pipe supplied by a private well

Check valve requirement for a plastic water service pipe supplied by a private well

Project Description

The project is the construction of a new single-family dwelling.  The potable water for the dwelling is supplied by a private well on the property and utilizes a water service pipe made of plastic suitable for cold water use only.

Applicable Code requirements (BCBC 2024 Book II (Plumbing Systems))

Sentence 1.4.1.2., Division A, Defined Terms

Water service pipe means a pipe that conveys water from a public water main or private water source to the inside of the building.

Sentence 2.6.1.5.(1), Division B, Check Valves

(1) A check valve shall be installed at the building end of a water service pipe where the pipe is made of plastic that is suitable for cold water use only.

Decision being appealed (Local Authority’s position)

A check valve is required at the building end of the water service pipe.  There is no “or” statement or exceptions to the requirement, such as if the water is supplied by a private well or if any hot water appliance has an integrated check valve.

Appellant's position

Under Sentence 2.6.1.5.(1), Division B, backflow prevention is required where a potable water system may be subject to contamination.  However, in a single-family dwelling supplied by a private well, an additional check valve at the water entry is generally redundant.

A private well system already includes a check valve at the well or pump assembly to prevent reverse flow and maintain system pressure, effectively isolating the water source.  In addition, most hot water heaters incorporate a check valve on the cold water inlet, further preventing backflow within the building’s potable water system.

Given these protections and the absence of any connection to a municipal supply, installing another check valve at the building entry does not provide meaningful addition protection and may instead contribute to increased system pressure from thermal expansion unless properly mitigated.

Appeal Board Decision #1994

The Board confirms the decision of the local authority.

It is the determination of the Board that a check-valve is required at the building end of the water service pipe suitable for cold water use only.

Reason for decision

The definition of water service pipe includes a pipe conveying water from a private water source.

As is indicated by the Functional Statements and Objective attributed to Sentence 2.6.1.5.(1), Division B, the requirement for a check valve is related to the prevention of damage to the pipe (and subsequent damage to the building) that may occur if the pipe is exposed to hot water.  The requirement applies equally to water service pipes connected to public and private water sources.

Unlike some of the requirements in Subsection 2.6.2, Division B, the check valve requirement in Sentence 2.6.1.5.(1), Division B, is not specifically related to protecting the water source from contamination.

Don Pedde
Chair, Building Code Appeal Board 

Dated:  February 5, 2026