Greener Building > Water Recycling and Reuse

Wastewater Recycling

Recycled wastewater systems disinfect water collected from showers and baths, laundry, and bathroom sinks for non-potable water uses including irrigation and toilets. Although treating greywater requires an initial capital investment, doing so conserves water and can yield savings in annual water bills. Review the examples below and consider installing a water recycling system when building a new facility or renovating an existing building.

Wastewater recycling can save money

Unilever, which produces over 400 brands of home, personal care, and food products, performed a water audit of a laundry detergent factory in Georgia in 1995 and then embarked upon a program of increased efficiency efforts, including rainwater collection, wastewater reuse, and educating employees on the economic and environmental importance of water conservation. These improvements save the company over $100,000 a year.

Solaire Apartments, located in Battery Park in New York City, was built in 2003 and contains 250 units. Water from irrigation, cooling towers, and toilets is collected, treated, and reused again for those purposes. The system reduces the building’s freshwater use by 75%.

More Wastewater Recycling Examples: Environmental Protection Administration Region 9 Water Recycling and Reuse webpage

Rainwater Harvesting

Collecting rainwater off roofs for reuse can be an environmentally preferable and a potentially economical approach to fulfilling a portion of your facility’s water needs. Rainwater catchment systems, which can include cisterns, rain barrels, and other simple devices to capture and reuse rainwater, can be designed and installed on a small scale as well as at larger scales.

Review the examples below, and consider installing a rainwater catchment system when embarking upon new construction or renovation.

Rainwater catchment examples

  • United Nations Environmental Program international examples
  • NRDC’s Santa Monica Office
  • Olympiastadion, Berlin, Germany
    • This venue for the 2006 FIFA Soccer World Cup uses a rainwater harvesting system that diverts rainwater into one of the largest cisterns in Europe, capable of storing over 49,000 cubic feet of water. The cistern supplies non-potable water for uses such as irrigating the soccer field.
  • Massachusetts Institute of Technology Stata Center
    • Stormwater/rainwater catchment system provides water for non-potable uses such as toilets. Case Study

Environmental Benefits

Almost half the world’s population lives without a reliable supply of clean drinking water. In the United States, many sources of freshwater are being depleted faster than they can be recharged by natural processes. This is especially true in the Southwest. The Colorado River, for example, which supplies water to 30 million people in seven states and Mexico, is at its lowest level since water flow records began being kept about 100 years ago. It often runs dry before it reaches the sea, adversely impacting farmers, residents, and aquatic life. Water conservation is especially important in light of the looming pressures of global warming, which threaten to significantly increase evaporation as well as instances of severe drought. Water scarcity will rival sea level rise as one of the consequences of global climate disruption.

Recycling wastewater helps reduce pressure on drinking water resources. Harvesting rainwater helps preserve natural water resources and stream and river ecosystems. Rainwater catchment systems also can reduce the need to transport water from distant locations, thereby reducing energy use and infrastructure requirements. Water conservation measures can help to ensure that future generations have access to the water they need.

Additional Resources

Environmental Protection Administration Region 9 Water Recycling and Reuse webpage
Florida Department of Environmental Protection Water Reuse website
Texas Guide to Rainwater Harvesting
United Nations Environmental Program introductory guide for decision makers
American Rainwater Catchment Systems Association
The Nine Mile Run Rain Barrel Initiative