Massachusetts Plumbers Journeyman Practice Exam

What color should non-potable water lines be painted based on the provided information?

1. Blue

2. Green

3. Red

4. Yellow

The correct answer is: Yellow

Non-potable water lines are designated to carry water that is not suitable for drinking. In plumbing and water management, color coding is essential for safety and efficient identification of different types of water lines. The standard practice is to paint non-potable water lines yellow. This designation helps prevent confusion and reduces the risk of accidental use of non-potable water for drinking or cooking, thereby enhancing safety for consumers. The use of yellow for non-potable water provides a clear visual cue that distinguishes these lines from potable (drinkable) water lines, which are typically marked in blue. Additionally, using distinct colors helps workers in the field quickly identify the type of water being dealt with, ultimately promoting better hygiene practices and awareness among all users and operators.