Integrating external costs into water utility asset management : an application of the threshold break rate method

The goal of an asset management program is to minimize the life-cycle cost of water utility assets, while continuing to provide the service levels expected by utility customers. The life-cycle cost of an asset includes both the utilitys internal costs to maintain the asset, and external costs borne by customers, the community, and the environment when the asset fails. This project demonstrates how to integrate external costs into asset management through an application of the threshold break rate model, a pipe-replacement decision-model that minimizes the life-cycle cost of water mains. The model is employed to determine which six-inch-diameter steel water pipes in the Albuquerque Bernalillo County Water Utility Authority (ABCWUA) distribution system should be scheduled for replacement. The external costs of water outages, estimated through a choice-experiment survey of ABCWUA residential customers, are included in the model, and model outputs with and without external costs are compared. Assuming a 5% discount rate, 6% percent more pipes in the distribution system are recommended for replacement when external costs are taken into consideration. The threshold break rate model is appealing because it does not require estimation of future pipe-break rates, and it can be used even when a full history of pipe breaks is not available. However, data from the ABCWUA may not satisfy an underlying assumption of the model that the function representing the present worth of a pipe over time is unimodal

Gap Analysis Based Decision Support Methodology to Improve Level of Service of Water Services

One of water utility’s managerial challenges is to make a balance in between two distinctive managerial goals, cost-effective provision of water service and improving customer satisfaction of water service. As management priorities of the water utility perspective do not reconcile from the customer’s perspective, this gap challenges the sustainable provision of water service. In this study, the new methodology based on a gap analysis was proposed to improve the Overall Level of Service (O-LOS) of water service. Two new indexes (Gap Index [GI] and the Efficiency Index [EI]) were developed to improve the O-LOS and minimize the gap between the customers and the service providers. The methodology proposed in this study is effective in supporting the water utility decisions on budget allocation to make a balance in between the customers’ demand and the service providers’ needs

Achieving effective asset management for water and wastewater utilities: A comparison of policy options for a special district and a medium city

This project developed a model for effective asset management drawn from successful programs in the United States, Australia, and New Zealand. Asset management practices were examined at the City of Ontario Utilities Department; a medium sized utility, and also at the Rainbow Municipal Water District, a small sized utility. Gaps between the ideal model and the existing practices were investigated

Risk-Based Decision-Making Modeling for Wastewater Pipes

The dissertation research work described here has three primary objectives under risk-based decision making. (1) The development of a comprehensive sewer pipe condition rating model that incorporates many environmental, structural, and hydraulic parameters. (2) The development of a sewer pipe deterioration model used to predict future overall condition states of the pipe, as well as determining the probability of failure at any given age of the pipe. (3) The development of a comprehensive consequence of failure model that assesses the consequence of sewer pipe failure using economic, social, and environmental cost factors. The Pipeline Assessment and Certification Program (PACP) was developed by the National Association of Sewer Service Companies, the industry-accepted protocol for condition rating sewer pipes in the US. The PACP method relies exclusively on visual inspections performed using Closed-Circuit Television (CCTV), where existing structural and operation and maintenance (O&M) defects are observed by certified operators. A limitation of the PACP method is that it does not use pipe characteristics, depth, soil type, surface conditions, pipe criticality, capacity, the distribution of structural defects, or history of preventative maintenance to determine the condition rating of the sewer pipe segment. Therefore, a comprehensive rating model with pipe characteristics, external characteristics, and hydraulic characteristics was developed. The calculating of a comprehensive rating is an entirely manual process. Therefore, this research work addresses this limitation of Analytical Hierarchy Process (AHP) and suggests AHP is not a suitable method to calculate comprehensive rating. Develops a faster calculation of a comprehensive rating model using and K-NN that incorporates pipe characteristics, environmental characteristics, and information about PACP structural score and PACP O&M score in hydraulic factors. Factors such as pipe age, pipe material, diameter, shape, depth, soil type, loading, carried waste, seismic zone, PACP structural score, and PACP O&M score are used. Our proposed model is applied to the data received from the City of Shreveport, LA, which is currently under a Federal Consent Decree. The results of a comprehensive rating model showed a below-average validity percentage because linear regression assumes a linear relationship between the input and output variables. Still, the relationship between response and the predictor is not linear for AHP to prove AHP is not a suitable method and satisfactory results for K-NN. As part of decision-making, for capital improvement planning and budgeting, the capacity to predict future sewer pipe conditions and potential breakdowns is essential. In contrast to the often-used Discrete Time Markov Chain approaches in the literature, the deterioration model created here uses a Continuous Time Markov Chain method to calculate the likelihood that a pipe will change from a better to a worse condition at given age. The consequence of the pipe\u27s failure is established to ascertain the risk of failure and to create a comprehensive framework for risk-based decision-making. To estimate the impact of the asset\u27s failure, the established consequence of failure model considers a significant number of economic, social, and environmental cost elements. For budgeting future capital projects and improvements, the CTMC model and failure consequences for sewers are useful

Automated Defect Detection Tool For Sewer Pipelines

In sewer networks, the economic effects and costs that result from a pipeline break are rising sharply. In Qatar, majority of the sewer network pipelines were installed in the last 20 years and are currently in poor condition and constantly deteriorating. As a result, there is huge demand for inspection and rehabilitation of sewer pipelines. In addition to being inaccurate, current Practices of sewer pipelines inspection are time consuming and may not keep up with the deterioration rate of the pipelines. Consequently, this research aims to develop an automated tool to detect different defects such as cracks, deformation, settled deposits and joint displacement in sewer pipelines. The automated approach is dependent upon using image-processing techniques and several mathematical formulas to analyze output data from CCTV camera photos. Given that one inspection session can result in hundreds of CCTV Camera footage, introducing an automated tool would help yield faster results. Additionally, given the subjective nature of most defects, it will result in more systematic results since the current method rely heavily on the operator's experience. The automated tool was able to successfully detect cracks, displaced joints, ovality and settled deposits in pipelines using CCTV Camera inspection output footage. Using two different data sets, the constructed Matlab code could successfully differentiate between cracks and displaced joints with an overall crack detection success rate of 84% and an overall displaced joint detection rate of 94%. The code was also able to efficiently detect settled deposits in the pipelines with a detection rate of 90%. In addition, the automated ovality detection resulted in 100% compatibility with the manual circularity detection

Automating Water Capital Activities Using Naïve Bayes Classifier with Supervised Learning Algorithm

Municipal governments have the responsibility to provide safe drinking water to residents. Maintaining water infrastructure systems to keep a certain level of service is a vital service. It is possible by assessing all assets and planning capital work activities to renew and renovate the existing assets. The municipalities prioritize the capital activities of their infrastructure and are required to optimize their available resources. Past studies confirmed due to several complexities and imperfections of the available water network data, there is a need for a comprehensive multicriteria database to prioritize pipe capital plan decisions based on engineering expert judgment. This database must include information about water pipe physical condition and performance up to an acceptable level of service and criticality based on the water pipe location. In addition, the lack of standard regulatory requirements due to incomplete condition, criticality and performance assessment of the entire Municipal Water Network (MWN) leads to bias and undefendable engineering judgment. Although several pipe prioritization models have been developed and published in the literature, no comprehensive multi-decision criterion model is available to date, including the pipe segment condition, performance, and criticality. In this research, a novel Priority Action Number (PAN) is developed and parameterized based on pipe segment condition, performance and criticality. An automated Naïve Bayes Classifier (NBC) with a supervised machine learning model is proposed for consistent, defensible and personnel independence ranking of existing water pipe condition, performance, and criticality of all water pipes through MWN. This methodology automates the capital activities decision-making process. The research presents and develops a prioritizing approach for the MWN capital activities and aids in selecting assistive technology for rehabilitation and renewal capital activities. The developed model is applied to the City of London MWN database in a Geographical Information System (ArcGIS) database to validate and verify the model. The multi-level classifier model classified and assigned a capital work activity to all pipes in the City of London MWN. The presented multi-level NBC with a supervised learning algorithm replicates the expert's opinion and engineering judgement. Through NBC supervised machine learning algorithm, the capital project decision-making process is automated. This methodology will add consistency and defensibility to capital programs. Using this algorithm can help utility save money by automating industry best practices and optimizing long-term decisions about the order in which pipes need to be staged into capital works programs

Impacts of Colombia's current irrigation management transfer program

Privatization / Irrigation management / Irrigated farming / Policy / Costs / Economic aspects / Operations / Maintenance / Agricultural production

Designing a Culvert Management System for the Town of Spencer, MA

Twenty-two road-stream crossings were assessed for the Town of Spencer, MA and the River and Stream Continuity Database. Each culvert, bridge, or dam was profiled to identify any constraints and possible considerations for future maintenance or replacement. A structural module was designed to assess the current condition of the crossings and work alongside the River and Stream Continuity Project, which does not have a structural component. The resulting analysis was presented to the attention of the Spencer Water Department

Analyzing the cost-effectiveness of enhancement approaches for rehabilitating water distribution network

Sustainable water management has been a trending goal in the world. Non-revenue water (NRW) is one of the forms of water loss. There is a tremendous amount of NRW, especially in developing countries. The real losses represent the more significant portion of the NRW. These losses negatively affect the economy and formulate a barrier towards reaching water sustainability. Therefore, the aim of the study was to that reduce NRW. A systematic review was first conducted to find the relevant techniques and methods for rehabilitating water distribution networks (WDN), which is one of the methods to reduce NRW and to achieve the research aim which is reducing the NRW, after identifying the WDN rehabilitation approaches, a questionnaire survey in Malaysia and Egypt was carried through five months period from June 2020 to October 2020. The main aim of the questionnaire survey was to identify cost-effective enhancement approaches. A total of 109 respondents from Malaysia and 67 respondents from Egypt, which means a total of 176 respondents were collected and analyzed. The sample size is suitable as most of the targeted population are among the managers and project managers with at least three years of experience in the WDN field. The population was determined based on the top companies and water authorities as the research focuses on advanced WDN rehabilitation enhancement approaches. Then, Cronbach’s alpha, mean score ranking, normalization value, and agreement analysis were carried in the data analysis phase. The results show that cost-effective enhancement approaches are programming, models, supervisory control and data acquisition (SCADA), and twin digital. Additionally, the data from Malaysia suggest two more cost-effective enhancement approaches: zoning network and genetic algorithm. These two techniques might possess great potential for other developing countries, such as Egypt. Then finally, after identifying the cost-effective approaches, a comparison between the cost-effective approaches between Malaysia and Egypt was done. Choosing the right technique can help industry practitioners maximize the benefits of WDN rehabilitation. The comparison would help the researchers and industry participants to adopt and further develop the suggested approaches. The discussion of the WDN enhancement rehabilitation approaches can help in adapting them from other countries in the future. Proper WDN rehabilitation supports NRW reduction, which mainly helps move towards sustainable water management in developing countries. Keywords: Sustainable development, water losses, Non-revenue water (NRW), Water distribution network (WDN), Rehabilitation of WD