What is greywater primarily defined as?

Greywater is primarily defined as water that has been used in household activities but does not contain significant levels of contaminants. This category specifically includes water from showers, bathtubs, sinks, and washing machines. Because it is relatively clean compared to other wastewater types, greywater can often be reused for purposes such as irrigation or flushing toilets, helping to conserve water resources.

The sources of greywater are particularly beneficial because they have minimal health risks, making it suitable for various recycling applications. In contrast, water from toilets is classified as blackwater due to its higher contamination level. Rainwater harvested from roofs, while useful for various applications, is not considered greywater. Furthermore, limiting greywater's definition solely to landscape irrigation does not accurately capture its broad usage potential; rather, it encompasses a variety of domestic water sources.