American Water Leverages the Water-Energy Nexus to Gain Efficiency
While many Americans know the importance of saving both energy and water, few know the direct connection between the two. Water and energy are intimately interrelated—using water more efficiently conserves energy and, ultimately, decreases carbon emissions. Just as other industries have been “going green” in recent years, the water industry has likewise developed ways to use its resources more efficiently.
American Water has deployed various technologies and practices to use water with greater efficiency, to prevent leaks, and, ultimately, to save energy. Leak detection—Developed comprehensive water preservation and efficiency strategies utilizing leak detection technologies that support conservation and consumption changes significantly impacting overall supply. For example, in Connellsville, Pennsylvania, MLOG acoustic leak detectors and an advanced metering infrastructure system were deployed, resulting in nonrevenue water dropping by more than half, from over 25% within six months, saving about $175,000 in annual water purchase costs in just the first year.
Pumping water—Increased use of variable speed drives on pumps by installing them on at least one pump in each station or plant to vary the pumping rate so it only pumps what is needed at a specific time, thus saving energy. American Water also launched a pump efficiency initiative that identifies inefficient pumps and either replaces or rehabilitates them to improve efficiency.
Alternative energy—In 2005, Pennsylvania American Water committed to operate its Yardley Water Treatment Plant with 100% pollution-free, wind-generated electricity. As a result, each year, the company purchases 1,603,200 kWh of green power, which is the environmental equivalent of planting more than 119,000 trees or not driving 1.5 million miles each year. In New Jersey, American Water installed the state’s largest ground-mounted solar electric system at its Canal Road Water Treatment Plant in Somerset, as part of an energy savings initiative. The system, which can produce up to 730,000 kilowatt-hours of energy a year, supplements 20% of the peak usage power needed to run the plant. Reducing energy usage by 585,000 kilowatt-hours a year prevents 1,577 pounds of nitrogen oxide, 4,875 pounds of sulfur dioxide, and 699,856 pounds of carbon dioxide from being emitted into the air. This savings in carbon dioxide pollution is equivalent to planting 94 acres of tree seedlings or preserving 2.6 acres of land from deforestation.
The company also installed solar modules on a reservoir at the Canoe Brook Water Treatment Plant in Millburn, New Jersey. This is the first solar array on the East Coast on a body of water designed to withstand a freeze/thaw environment. Annually, the solar field will produce 135,000 kilowatt hours per year, or approximately 2% of the plant’s power.
As we confront the challenges posed by climate change, persistent droughts, and high energy prices across the country, nearly everyone is looking for ways to conserve resources and cut costs. The solutions above not only make environmental sense, they make economic sense as well.
[Editor's Note: This case study was featured in Achieving Energy and Water Security: Scalable Solutions from the Private Sector.]