What purpose do purple pipes serve in irrigation systems?

Purple pipes are specifically designed for the reuse of treated graywater in irrigation systems. This type of piping indicates that the water inside is not potable, meaning it is not suitable for drinking but can be safely used for landscape irrigation, flushing toilets, or other non-potable applications. The use of purple pipes supports water conservation efforts by recycling wastewater, which decreases the demand for fresh water resources while promoting sustainable practices in landscaping and agriculture.

The options related to surface irrigation, subsoil irrigation, and stormwater drainage do not reflect the specific purpose that purple pipes serve. While these irrigation methods deal with various techniques for managing water, they do not involve the reuse of graywater. Thus, the correct function of the purple pipes aligns closely with the concept of graywater reuse, emphasizing their role in sustainable water management practices.