Massachusetts Plumbers Journeyman Practice Exam

How should potable water lines be marked according to the provided text?

1. Blue

2. Green

3. Red

4. Yellow

The correct answer is: Green

Potable water lines should be marked with blue. This color coding is consistent with industry standards and practices that facilitate the quick identification of different types of utilities and services. Blue specifically signifies that the lines carry potable or drinkable water, which is crucial for ensuring safety and compliance with plumbing codes. Understanding this marking system helps prevent cross-connections and potential contamination, as workers can easily recognize what each line contains, ensuring proper handling and maintenance of water services.