Which statement best defines graywater and its typical reuse applications?

• A. Graywater is wastewater from toilets that is treated for reuse in irrigation.
• B. Graywater is relatively clean wastewater from sinks, showers, and laundry that is reused for non-potable uses such as toilet flushing and irrigation where code permits.
• C. Graywater is rainwater collected from rooftops used for potable supply.
• D. Graywater is groundwater treated to be potable.

Answer: (B)

Graywater is relatively clean wastewater from household sources such as sinks, showers, and laundry that can be reused for non-potable tasks like toilet flushing and landscape irrigation when allowed by code. It is distinct from blackwater, which comes from toilets, and from rainwater or groundwater meant for potable use. In practice, graywater is treated or filtered enough to reduce odor and contaminants and is conveyed through a separate plumbing pathway to non-potable outlets, helping save fresh water while staying within health and safety regulations. The other statements mix in toilet waste, rainwater for drinking, or potable groundwater, which don’t describe graywater.