Embodied Energy in the Water Cycle

Wastewater reclamation produces a recycled product. The traditional linear approach to water resource management is increasingly proving to be unsustainable due to water stress being placed on urban water management. By nature reclamation is a process that reduces the energy consumed in the water cycle and therefore is the cornerstone of sustainability in the management of water resources. The value of reclaimed water includes the embodied energy that is reclaimed from the water cycle. This paper provides the methodology for establishing a value chain in determining the economic benefit of water reclamation and identifies ways for communities to take the first steps of this resource as a strategy to reduce greenhouse gases, carbon footprint and a sustainable principle of water portfolio management. Until recently, the embodied energy in wastewater reclamation has been a hidden value not considered in a full life cycle analysis9. The value of reclaimed water includes the embodied energy that is reclaimed from the water cycle. When embodied energy in reclaimed water is accounted for over a 50 year life cycle term, at 12 cents per kilowatt-hour and not including interest it has a value between $8.5 to $14.8 million dollars per million gallons. The capital cost and operating cost for the reclaimed water infrastructure is a minimal cost when compared with the overwhelming operational energy recovery savings. If you want to truly be sustainable wastewater reclamation is the cornerstone that provides the greatest environmental benefit. Water conservation, while an important component of a sustainable water resources management plan does not provide the same value chain impact in terms of reducing the carbon footprint and does not reclaim the energy already embodied in the water product. Source: WEFTEC 2009 Proceedings