Recent advances in calculating economic intervention frequency for active leakage control, and implications for calculation of economic leakage levels

A.O. Lambert; M. Fantozzi

doi:10.2166/ws.2005.0072

Recent advances in calculating economic intervention frequency for active leakage control, and implications for calculation of economic leakage levels

Water Science & Technology Water Supply ◽

10.2166/ws.2005.0072 ◽

2005 ◽

Vol 5 (6) ◽

pp. 263-271 ◽

Cited By ~ 10

Author(s):

A.O. Lambert ◽

M. Fantozzi

Keyword(s):

Task Force ◽

Control Policy ◽

Practical Method ◽

Confidence Limits ◽

Natural Rate ◽

Water Losses ◽

Technical Management ◽

Leakage Control ◽

Short Run ◽

Current Water

During the last decade, IWA Water Losses Task Force members have developed a systematic practical approach to the technical management of non-revenue water and its components, with (since 2002) increasing use of 95% confidence limits in these calculations. The current Water Losses Task Force has recently set itself an objective to develop a quick and practical method for calculating economic intervention (for active leakage control to locate unreported leaks and bursts), and short-run economic leakage level. This paper outlines a quick and practical method for assessing economic intervention frequency (and associated budgetary and volumetric parameters) for an active leakage control policy based on regular survey. Calculations are based on three key parameters: natural rate of rise of unreported leakage, marginal cost of water, and cost of intervention. It is hoped this will encourage Utilities that do not currently undertake active leakage control to adopt an ongoing basic active leakage control policy which can be simply demonstrated as being economic for their own situation.

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Some international experiences in promoting the recent advances in practical leakage management

Water Practice & Technology ◽

10.2166/wpt.2006.026 ◽

2006 ◽

Vol 1 (2) ◽

Author(s):

Marco Fantozzi ◽

Alain Lalonde ◽

Allan Lambert ◽

Tim Waldron

Keyword(s):

North America ◽

Water Loss ◽

Task Force ◽

Pressure Management ◽

Water Losses ◽

Active Pressure ◽

International Experiences ◽

Recent Advances ◽

Leakage Control ◽

Water Loss Management

Substantial advances have been made by the IWA Water Losses Task Force in the last few years in the development of practical water loss management methods, including the benefits of active pressure management, calculation of economic intervention frequency for active leakage control, and economic levels of leakage. This paper reviews experiences to date in introducing and disseminating these advances to Utilities internationally, with particular reference to Australia, Europe, and North America.

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Multi-model study of HTAP II on sulphur and nitrogen deposition

10.5194/acp-2017-1121 ◽

2018 ◽

Cited By ~ 1

Author(s):

Jiani Tan ◽

Joshua S. Fu ◽

Frank Dentener ◽

Jian Sun ◽

Louisa Emmons ◽

...

Keyword(s):

North America ◽

East Asia ◽

South Asia ◽

Wet Deposition ◽

Task Force ◽

East Asian ◽

Control Policy ◽

N Deposition ◽

Eastern United States ◽

S Deposition

Abstract. This study uses multi-model ensemble results of 11 models from the 2nd phase of Task Force Hemispheric Transport of Air Pollution (HTAP II) to calculate the global sulfur (S) and nitrogen (N) deposition in 2010. Modelled wet deposition is evaluated with observation networks in North America, Europe and Asia. The modelled results agree well with observations, with 76–83 % of stations having predicted within ±50 % of observations. The results underestimate SO42−, NO3− and NH4+ wet depositions in some European and East Asian stations, but overestimate NO3− wet deposition in Eastern United States. Inter-comparison with previous projects (PhotoComp, ACCMIP and HTAP I) shows HTPA II has considerably improved the estimation of deposition at European and East Asian stations. Modelled dry deposition is generally higher than the “inferential” data calculated by observed concentration and modelled velocity in North America, but the inferential data has high uncertainty, too. The global S deposition is 84 Tg(S) in 2010, with 49 % of the deposits on continental regions and 51 % on ocean (19 % on coastal). The global N deposition consists of 59 Tg(N) oxidized nitrogen (NOy) deposition and 64 Tg(N) reduced nitrogen (NHx) deposition in 2010. 65 % of N is deposited on the continental regions and 35 % is on ocean (15 % on coastal). The estimated outflow of pollution from land to ocean is about 4 Tg(S) for S deposition and 18 Tg(N) for N deposition. Compared our results to the results in 2001 from HTAP I, we find that the global distributions of S and N depositions have changed considerably during the last 10 years. The global S deposition decreases 2 Tg(S) (3 %) from 2001 to 2010, with significant decreases in Europe (5 Tg(S) and 55 %), North America (3 Tg(S) and 29 %) and Russia (2 Tg(S) and 26 %), and increases in South Asia (2 Tg(S) and 42 %) and the Middle East (1 Tg(S) and 44% ). The global N deposition increases by 7 Tg(N) (6 %), mainly contributed by South Asia (5 Tg(N) and 39 %), East Asia (4 Tg(N) and 21 %) and Southeast Asia (2 Tg(N) and 21 %). The NHx deposition is increased with no control policy on NH3 emission in North America. On the other hand, NOy deposition starts to dominate in East Asia (especially China) due to boosted NOx emission in recent years.

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ESCAPE DYNAMICS AND POLICY SPECIFICATION

Macroeconomic Dynamics ◽

10.1017/s1365100511000058 ◽

2011 ◽

Vol 17 (1) ◽

pp. 123-142 ◽

Cited By ~ 3

Author(s):

Michele Berardi

Keyword(s):

Policy Maker ◽

Policy Design ◽

Reduced Form ◽

Optimal Time ◽

Natural Rate ◽

Escape Dynamics ◽

Princeton University ◽

Trade Offs ◽

Policy Specification ◽

Short Run

In his monographThe Conquest of American Inflation(Princeton, NJ: Princeton University Press, 1999), Sargent suggests that the sharp reduction in U.S. inflation that took place under Volker may vindicate the type of econometric policy evaluation famously criticized by Lucas (Carnegie–Rochester Conference Series on Public Policy, 19–46, 1976). At the core of this vindication story is the escape dynamics, recurrent sliding away from the path leading to the time-consistent suboptimal equilibrium level of inflation and toward the low-inflation, optimal, time-inconsistent Ramsey outcome: by recurrently estimating a reduced-form model, in fact, the policy maker could periodically learn an approximate version of the natural rate hypothesis and therefore be induced to disinflate the economy. Two elements seem important in this story: the type of model used by the policy maker to represent the economy, whether structural or reduced-form, and the policy specification, whether derived taking the private sector's expectations as given or as endogenous to the policy design. Although Sargent (1999) stresses the first element, we find that it is instead the second aspect that is crucial to generate recurrent periods of low inflation: the policy maker has to recognize the endogeneity of the private sector's expectations and refrain from exploiting ephemeral short-run trade-offs between inflation and unemployment.

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Applying the IWA approach to water loss performance indicators in Australia

Water Science & Technology Water Supply ◽

10.2166/ws.2003.0098 ◽

2003 ◽

Vol 3 (1-2) ◽

pp. 153-161 ◽

Cited By ~ 1

Author(s):

T. Carpenter ◽

A. Lambert ◽

R. McKenzie

Keyword(s):

Performance Indicators ◽

Best Practice ◽

Task Force ◽

Major Step ◽

Water Losses ◽

Data Set ◽

Task Forces ◽

Non Revenue Water ◽

And Performance ◽

National Workshop

In 1999 and 2000, IWA Task Forces on Water Losses and Performance Indicators published their conclusions of over three years research, analysis and discussions. For the topics of Non-Revenue Water, Water Losses, Apparent Losses and Real Losses, these included:a recommended standard terminology, with definitions and procedures for assessing these components of the Annual Water Balance;recommended performance indicators for each of these components. This work represents a major step forward in defining the “best practice” approach to assessing and presenting components of Non-Revenue Water, for more rational comparisons of performance in diverse systems within a single organisation, within the same country, and between countries. The 21 members of the Water Services Association of Australia (WSAA) provide water and wastewater services to 12.9 million Australians. WSAA seeks to promote “best practice”, and act as a national focus for all interested parties. In February 2000 WSAA organised a national Workshop in Melbourne to discuss the IWA methodology. Arising from this Workshop, WSAA commissioned the production of customised Software and an Associated User Manual known as “Benchloss”, to promote and facilitate the application of the IWA recommended methodology throughout Australia. The paper will describe the development and application of “Benchloss” to date, with a comparison of Australian performance data against an International Data Set used by the Water Losses Task Force.

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Water Network-Failure Data Assessment

Energies ◽

10.3390/en13112990 ◽

2020 ◽

Vol 13 (11) ◽

pp. 2990

Author(s):

Katarzyna Pietrucha-Urbanik ◽

Barbara Tchórzewska-Cieślak ◽

Mohamed Eid

Keyword(s):

Water Supply ◽

Failure Mode ◽

Failure Modes ◽

Task Force ◽

Supply System ◽

Water Supply System ◽

Normal Operation ◽

Water Leakage ◽

Water Losses ◽

Leakage Failure

The water-supply system is one of the basic and most important critical infrastructures. Water supply service disruption (water quality or quantity) may have serious consequences in modern societies. Water supply service is subject to various failure modes. Failure modes are specified by their degradation mechanisms, criticality, occurrence frequency and intensity. These failure modes have a random nature that impacts on the network disruption indicators, such as disruption frequency, network downtime, network repair time and network back-to-service time, i.e., the network resilience. This paper focuses on the water leakage failure mode. The water leakage failure mode assessment considers the unavoidable annual real water losses and the infrastructure leakage index recommended by the International Water Association’s Water Loss Task Force specialist group. Probabilistic statistical modelling was implemented to assess the seasonal index, the failure rates and the expectation value of the “mean time between failures.” The assessment is based on real operational data of the network. Specific attention is paid to the sensitivity of failures to seasonal variations. The presented methodology of the analysis of the water leakage failure mode is extendable to other failure modes and can help in developing new strategies in the management of the water-supply system in normal operation and crisis situations.

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Market Power, NAIRU, and the Phillips Curve

Abstract and Applied Analysis ◽

10.1155/2020/7083981 ◽

2020 ◽

Vol 2020 ◽

pp. 1-18

Author(s):

Derek Zweig

Keyword(s):

Interest Rates ◽

Phillips Curve ◽

Functional Form ◽

The United States ◽

Medium Term ◽

Natural Rate ◽

Natural Rate Of Unemployment ◽

Long Run ◽

Weak Evidence ◽

Short Run

We explore the relationship between unemployment and inflation in the United States (1949-2019) through both Bayesian and spectral lenses. We employ Bayesian vector autoregression (“BVAR”) to expose empirical interrelationships between unemployment, inflation, and interest rates. Generally, we do find short-run behavior consistent with the Phillips curve, though it tends to break down over the longer term. Emphasis is also placed on Phelps’ and Friedman’s NAIRU theory using both a simplistic functional form and BVAR. We find weak evidence supporting the NAIRU theory from the simplistic model, but stronger evidence using BVAR. A wavelet analysis reveals that the short-run NAIRU theory and Phillips curve relationships may be time-dependent, while the long-run relationships are essentially vertical, suggesting instead that each relationship is primarily observed over the medium-term (2-10 years), though the economically significant medium-term region has narrowed in recent decades to roughly 4-7 years. We pay homage to Phillips’ original work, using his functional form to compare potential differences in labor bargaining power attributable to labor scarcity, partitioned by skill level (as defined by educational attainment). We find evidence that the wage Phillips curve is more stable for individuals with higher skill and that higher skilled labor may enjoy a lower natural rate of unemployment.

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Use of district metered areas coupled with pressure optimisation to reduce leakage

Water Science & Technology Water Supply ◽

10.2166/ws.2008.030 ◽

2008 ◽

Vol 8 (1) ◽

pp. 57-62 ◽

Cited By ~ 4

Author(s):

Bambos Charalambous

Keyword(s):

Water Loss ◽

Distribution Systems ◽

Water Distribution ◽

Task Force ◽

Early Stage ◽

Supply And Demand ◽

Integrated Approach ◽

Water Shortage ◽

Climatic Conditions ◽

Water Losses

Water shortage and the future threat posed by changing climatic conditions has intensified the need for the development of appropriate water management approaches, which aim at keeping a balance between water supply and demand. Losses from water distribution systems must be of concern to every water utility, especially in areas of our planet where water is found in very limited quantities. It is therefore imperative that water utilities apply simple and effective methodologies in accounting for water losses from their transmission and distribution systems. The Water Loss Task Force (WLTF) of the International Water Association (IWA) has established a water audit method, which traces water from its source right through the system and derives at the end the revenue and non-revenue component, in other words is a methodology for water accountability and an integrated approach to water loss control. The Water Board of Lemesos, Cyprus recognised at a very early stage the importance and significance of establishing a proper water audit system and has over the years developed its infrastructure in such a way in order to be able to account efficiently and accurately for all water produced. Reduction and control of water loss was achieved through the application of a holistic strategy based on the approach developed by the WLTF of the IWA. Integral part of this approach is the establishment and operation of DMAs.

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International Report: Water losses management and techniques

Water Science & Technology Water Supply ◽

10.2166/ws.2002.0115 ◽

2002 ◽

Vol 2 (4) ◽

pp. 1-20 ◽

Cited By ~ 61

Author(s):

A.O. Lambert

Keyword(s):

Performance Measures ◽

Distribution Systems ◽

State Of The Art ◽

Task Force ◽

The State ◽

Water Losses ◽

Task Forces ◽

International Report ◽

And Performance ◽

Unaccounted For Water

Since the 1991 IWSA International Report on “Unaccounted for Water and the Economics of Leak Detection”, the topic of management of water losses in distribution systems has received increased attention. This International Report seeks to present an overview of the “state of the art” in management of Water Losses, based on the Reports prepared by National Rapporteurs, the recent recommendations of the IWA Task Forces on Water Losses and Performance Measures, and improved concepts for modelling components of leakage and pressure: leakage relationships. The IWA Task Force recommendations provide overdue clarification and guidance on several issues that have caused persistent problems in quantifying Water Losses and comparing the effectiveness of their management. It is hoped that this Report will assist in the promotion of a more standardised international approach to the definition, assessment, monitoring and management of Non-Revenue Water and Water Losses.

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