Why Reuse?

Water used to flush toilets does not need to be treated to drinking water standards. Water reuse collects previously discarded water flows (i.e. alternative water sources) and treats them to the quality deemed safe for their intended end use (as defined by state or local standards). The scale of collection or distribution is another defining characteristic of water reuse systems, ranging anywhere from the building-scale to centralized. 

Different types of water reuse can benefit communities in different ways depending on their source, end use and scale. Communities are most likely to allow the types of reuse that help mitigate their local water challenges. The sections below provide basics definitions for all options in each category** and summarizes which ones might be helpful in different situations.

• Collection/Distribution Scale
• Alternative Water Sources
• End Use Applications

**Please check state and local regulations to see which sources can be collected, at what scales, how they can be used, and what the applicable water standards are for your area.

Onsite and Distributed Configurations

Alternative Water Sources

Treated Municipal Wastewater

Treated wastewater effluent discharged from a centralized wastewater treatment plant of any size. Other terms referring to this source of water include domestic wastewater, treated wastewater effluent, reclaimed water, and treated sewage.

Stormwater

Precipitation that is collected from land or impervious surfaces at a district or regional scale for the purpose of beneficial reuse. Rainwater collection at the building scale is classified separately under 'onsite collected waters.’

Industry Process Water

Water produced during industrial and manufacturing processes. Other terms referring to this source of water include air handling condensate, boiler, cooling or wash water, and water generated during oil and natural gas extraction.

Onsite Collected Sources

Water sources generated within or surrounding a building or district. Definitions for onsite-collected rainwater, stormwater, greywater, blackwater, air conditioning condensate, and foundation drainage are shown in the image below. 

Original Photo Credit: San Francisco Public Utilities Commission

End Use Applications

**Please check state and local regulations to see which sources can be collected, how they can be used, and what the applicable water standards are for your area.