GEF

Unit 3  |  Primary Sustainability Issues 78 water prices increase with higher rates of use, an approach that reliably limits waste. Another simple yet effective approach to water conservation is water metering . The U.S. Environmental Protection Agency estimates that providing households with an accurate measure of water use can reduce consumption by 20 to 40 percent. Other strategies include installing low-flush toilets and low-flow showerheads, and recycling greywater —previously used water—from sinks and showers for use in watering lawns and other non-potable applications. Some buildings also use rain barrels or rooftop water collectors for capturing rainwater and storing it for household use. Americans currently use approximately 100 gallons of water per person per day for household purposes such as drinking, bathing, cooking, and watering lawns. But, as with energy, most economic and environmental costs of water use are hidden. For instance, it takes 53 gallons of water to produce one glass of milk and 634 gallons of water to produce an 8-ounce steak. Consequently, the per capita water foot- print in the U.S. is close to 1,800 gallons per day, more than twice the average in other industrialized countries such as Germany. Truly sustainable water systems will recognize this hidden demand and prioritize products and services with a low water footprint. 3.6  Industrial Pollution and Toxins Reducing environmental toxins is another vitally important area of sustainability. Pollution has a widespread impact on human health. In the past 100 years, a vast range of syn- thetic chemicals have come into common use. During recent decades, scientists and activists have highlighted the dangers of many of these chemicals. However, the vast majority of syn- thetic chemicals remain unstudied and unregulated. WATER METERING The use of devices that show users their water use, often having a dramatic impact on water conservation. GREYWATER Wastewater that is created in homes or buildings that can be recycled onsite for irrigation, landscaping, or construction. WATER FOOTPRINT The amount of water that is used in various activities, such as food production. ENVIRONMENTAL TOXINS Chemicals in the environ- ment that cause harm to humans and other organ- isms. In a sustainability context, it refers to man- made chemicals such as DDT and PCBs.