Professional Practice

Improving Water Efficiency: Residential Water Recycling

Water collected on-site and stored in a 42,000 gallon cistern buried under the driveway. The water is used throughout the summer to replenish the pond to the left, as well as the fountains and irrigation for the plants. Ë¿¹ÏÊÓƵ 2016 Professional Residential Design Honor Award. Water Calculation and Poetic Interpretation, Monterey Cypress, California / Arterra Landscape Architects

Recycled water is treated wastewater that can be used for landscapes. There are multiple grades of recycled wastewater. Greywater is domestic wastewater from kitchen sinks, dishwashers, and washing machines, and may include household cleaning products and food particles. Blackwater refers to water used in toilets that contains human excrement. In total, 50 to 80 percent of water used in homes is recyclable. Greywater, and even blackwater, can be diverted and treated through a filter system and then further used to irrigate residential, commercial, and agricultural landscapes.

Decentralized greywater systems, which are installed at or near the point where wastewater is generated, can of landscape irrigation needs. Currently, however, reused water accounts for less than 1 percent of water used in the U.S., according to the National Academy of Sciences, due in part to concerns over safety of using reclaimed water for domestic purposes.

Depending on the extent of treatment, recycled water can be cleaner and safer to use than tap water. In an effort to maximize the use of recycled water, the city and county of San Francisco¡¯s requires property owners located within a designated area to install recycled water systems in new construction, modification, and remodeling projects. Each state has a set of specific regulations on the use of recycled water use, and some states require permits. Using recycled water can significantly reduce residential water waste, and therefore energy use and greenhouse gas emissions.

Source: , Green Living; ¡°,¡± National Academy of Science, 2012

Organizations








Research

¡°,¡± Laura Allen, Storey Publishing, 2015

¡°,¡± Art Ludwig, Oasis Design, 2015

, Lindsey E. Svete, Norwegian University of Life Sciences, Department of Mathematical Sciences and Technology

¡°,¡± National Academy of Science, 2012

Resources



, NPR

, Greenbiz

, Earth Institute, Columbia University

Government Resources

, San Antonio Water System

, Australian Government

, Orange County Water District, California



, City of San Diego, California

, Government of Canada

, Department of Planning and Development, City of Berkeley, California

, U.S. Environmental Protection Agency

, Los Angeles County Department of Public Health

Projects


Cornell University  

DBX Ranch, Pitkin County, Colorado
Design Workshop, Inc.

Water Calculation and Poetic Interpretation, Monterey Cypress, California
Arterra Landscape Architects

Urban Spring, San Francisco
Bionic San Francisco
, Tucson, Arizona
Design Workshop, Inc.