Incorporating Sustainability in Infrastructure ROI: The energy ... - rccao

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One dated estimate claims that pumping water accounts for seven per cent of totalelectricity consumption in the U.S. (Brailey and Jacobs, 1980). Figures for the fraction ofworld power consumption for pumping water differ and are not readily available. One studyindicates two to three per cent of total global energy production and seven per cent of totalelectricity consumption is allocated to pumping water (Watergy, 2004). The American WaterWorks Association Water Loss Control Committee indicates that 2-10 per cent of the powerconsumed in a given country is by water utilities (AWWA, 2003). Because of the large energyinput needed to treat and distribute potable water, a thorough understanding of the nature andcauses of energy loss in WDS is warranted and overdue, a statement no less true for Toronto orLondon as for Mexico City or Sao Paulo.In addition to water loss, leaks are costly in terms of energy consumption. Colombo andKarney (2002) raised this issue as part of a preliminary evaluation of the relative importance ofenergy waste via leakage. Further recognition of the energy cost of leaks was made in the AWWAWater Loss Control Committee’s 2003 report which acknowledged that “the additional energyneeded to supply leakage unnecessarily taxes energy generating capabilities” (AWWA, 2003).An early mention of the leak-energy link was by Cole (1912) who noted that the City ofChicago was burning twice as much coal as needed to supply customers due to substantiallosses (about 50 per cent). Though anecdotal, his observations were empirical and essentiallyconstituted an informal example of the first approach. Colombo and Karney (2002) addressedestimation of leakage’s energy impact from the other direction by developing and evaluating keyrelationships (leak size, system roughness and leak location) assuming knowledge of idealizedleaks in simple hypothetical systems and assuming equivalent service/delivery conditionsbetween leak and non-leak scenarios. They extended this analysis to systems with storage(Colombo and Karney, 2005). Bounds and Kahler (2006 [i] ) performed analyses for a largescalewater network and found that leak management could save 14 per cent of its electricalpower consumption.These contributions have not directly attached dollar values to the energy waste associated withleakage because they have concentrated on hypothetical systems with idealized characteristicsand cannot necessarily be extrapolated to real networks. While helpful for understandingleak-energy physics, it is the top-down auditing approach that is more likely to assist a givenutility in ascribing a monetary value to the energy burden of leaks. This would typically beginwith a system-wide water audit in order to account for the different sources of non-revenuewater (water that does not reach users and for which no customer is billed; referred to asunaccounted-for-water, UFW, in older parlance). This includes water used for street cleaning,park irrigation, fire fighting, sewer rehabilitation, illegal connections, accounting errors, meterinaccuracies etc., as well as water lost through leaks and breaks. Leakage is often a majorcomponent of non-revenue water. Thus, a good estimate of UFW is a good start to establishinghow much water is lost via leakage. Some data about UFW for select Ontario cities is presentedin the table on the next page.16 rccao.com
Extended Impacts Of LeaksThe determination of performance extends beyond the traditionally simplistic confinesof hydraulic “satisfaction” and financial cost, but also covers environmental and socialexternalities. Some of these externalities may be beneficial and could include the economicbenefits that water supply infrastructure can bring to a community or the public health benefitsof a reliable water supply to a hospital. Thus, the total cost of the system includes not onlythe financial cost of manufacturing and maintaining the infrastructure, but also encompassesthe health effects of poor water quality, the environmental impact of energy consumption andinefficiency, water loss due to leaks, disruptions and associated service losses due to breaks, anda variety of other burdens associated with the system and its operation.UFW Percent of Total Production in Each CityCity Percent of Total Production YearToronto 14% [ii] 2007Ottawa 22%-28% [iii] Another exact datum is 25.9% [iv] 2006London 8% [v] 2008Guelph 13% [vi] 2008Windsor 24.5%-25.5% [vii] 2008Vaughan 10.1% [viii] 2006Kingston At least 38% [ix] 2002Barrie 3.2% [ix] 2006Port Colborne 30% [ix] 2006Niagara Falls 28% [ix] 2006Thorold 25% [ix] 2006Chatham Kent 17% [ix] 2006There are also some data for Ontario and Canada; that is, 16 per cent (2008) unaccounted forwater in Ontario [ii] , and 20 per cent (2004) in Canada [iii] .Pipe breaks differ from leaks in that they require immediate attention. Thus, while theyusually only persist for short duration, they involve a large energy investment associatedwith repair operations. Apart from the obvious energy charge for excavation, replacing pipesegments entails a certain energy investment in terms of the embodied energy that goes intopipe manufacture. Moreover, emergency pipe repair usually spells traffic delays with theattendant emissions of GHGs from idling motor vehicles.In addition to introducing a troublesome potential to contaminate WDS and compromisepublic health, abandoned water mains may create their own energy burden upon system operation.Derelict pipes can promote energy loss if they remain “live” (that is, if they are still connected toIncorporating Sustainability in Infrastructure ROI 17
Page 1: An Independent Study Funded byIncor
Page 4 and 5: Table of ContentsExecutive Summary
Page 6 and 7: Executive SummaryWhile easily taken
Page 8 and 9: IntroductionInfrastructure and ener
Page 10 and 11: On average, the study found that th
Page 12 and 13: Public decision making has to be ba
Page 14 and 15: To map this into typical variables
Page 18 and 19: the system via an open link) and co
Page 20 and 21: Policy RecommendationsBy prioritizi
Page 22 and 23: Action ItemsThis report recommends
Page 24 and 25: ReferencesASCE—American Society o
Page 26 and 27: Appendix A: Estimating theSustainab
Page 28 and 29: Contingent Valuation: Also known as
Page 30 and 31: Appendix B:Water Leakage Issues and
Page 32 and 33: Deterioration: Deteriorated pipes l
Page 34 and 35: Endnotes[i]Bounds, Peter; Kahler, J
Page 36: RCCAO25 North Rivermede Road, Unit

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