National Center for Construction Education & Research (NCCER) Plumbing Level 1 Practice Exam

The LEED (Leadership in Energy and Environmental Design) standard emphasizes sustainability and encourages the development of systems that conserve water and reduce environmental impact. Among the options provided, graywater systems are specifically encouraged because they utilize wastewater generated from domestic activities—such as laundry, dishwashing, and bathing—that can be reused for irrigation and other non-potable applications. This approach helps decrease the overall demand for fresh water, promotes resource efficiency, and supports sustainable practices in building design.

Graywater systems contribute to the LEED goals by minimizing the use of potable water for non-drinking purposes, thereby enhancing water efficiency in commercial buildings. By implementing these systems, buildings can significantly reduce their water footprint, which is a key aspect aligned with LEED certification criteria focused on resource conservation.

While the other types of systems mentioned—stormwater systems, rainwater harvesting systems, and recycled water systems—are also beneficial and can contribute to sustainability, the specific emphasis of the LEED standard on graywater systems highlights their role in maximizing water conservation efforts within commercial applications.