Helena Mala-Jetmarova

An algorithm for minimization of pumping costs in water distribution systems using a novel approach to pump scheduling

The operation of a water distribution system is a complex task which involves scheduling of pumps, regulating water levels of storages, and providing satisfactory water quality to customers at required flow and pressure. Pump scheduling is one of the most important tasks of the operation of a water distribution system as it represents the major part of its operating costs. In this paper, a novel approach for modeling of explicit pump scheduling to minimize energy consumption by pumps is introduced which uses the pump start/end run times as continuous variables, and binary integer variables to describe the pump status at the beginning of the scheduling period. This is different from other approaches where binary integer variables for each hour are typically used, which is considered very impractical from an operational perspective. The problem is formulated as a mixed integer nonlinear programming problem, and a new algorithm is developed for its solution. This algorithm is based on the combination of the grid search with the Hooke–Jeeves pattern search method. The performance of the algorithm is evaluated using literature test problems applying the hydraulic simulation model EPANet.

Exploration of the Trade-Offs between Water Quality and Pumping Costs in Optimal Operation of Regional Multiquality Water Distribution Systems

AbstractThis paper explores the trade-offs between water quality and pumping costs objectives in optimization of operation of regional multiquality water distribution systems. The optimization model is designed to concurrently minimize each objective, where water quality is represented by the deviations of constituent concentrations from required values and pumping costs are represented by energy consumed by the pumps. The optimization problem is solved using an optimization software, incorporating the nondominated sorting genetic algorithm II (NSGA-II), linked with network analysis software. Two typical but purposefully different example networks are used. First, a network with multiple water sources of different qualities and second, a network with one water source only, which was converted to represent a regional nondrinking water distribution system. The trade-offs between water quality and pumping costs are explored using a total of 14 scenarios reflecting different water quality configurations of th...

Impact of Water-Quality Conditions in Source Reservoirs on the Optimal Operation of a Regional Multiquality Water-Distribution System

AbstractThe impact of water quality conditions in source reservoirs on the optimal operation of a regional multiquality water-distribution system is analyzed. The optimization model concurrently minimizes three operational objectives being pump energy costs, turbidity, and salinity deviations at customer demand nodes from allowed values. The optimization problem is solved using the optimization tool GANetXL incorporating the NSGA-II, linked with the network analysis software EPANet. The example network adapted from the literature captures some of the unique features of the Wimmera Mallee Pipeline in Australia. Six scenarios representing different water quality conditions in source reservoirs are analyzed. It was discovered that two types of trade-offs, competing and noncompeting, exist between the objectives and that the type of trade-off is not unique between a particular pair of objectives for all scenarios. These and other findings may be of particular use to system operators in their long-term operati...

Vulnerability of Water and Wastewater Infrastructure and Its Protection from Acts of Terrorism: A Business Perspective

Water and wastewater infrastructure, which is considered essential for contemporary human existence, has been subject to attacks and threats since ancient times. Recorded history indicates that the vulnerability of this infrastructure is a result of threats from both natural disasters and human intervention such as terrorist attacks. Subsequent to the terrorist attack on the Twin Towers in New York in 2001, some countries have introduced new legislation and systems to ensure adequate protection to water and wastewater infrastructure. From a business perspective, a unique approach to mitigate levels of threat is to introduce practical strategies to control risk. This is achieved with consideration of the concept of crisis leadership and crisis control. Additionally, these strategies include emergency and business continuity which are required to be effectively managed across water agencies. This methodology is illustrated with regularly practicing plans and procedures in the form of scripted crisis exercises. There are four major types of exercises which display processes, roles, and responsibilities with an accent on planning and documentation. Water and wastewater agencies which adopt these strategies will survive and produce a resilient organization. This chapter provides an overview of a preparedness and recovery framework suitable for water industries worldwide.

Erratum for “Exploration of the Trade-Offs between Water Quality and Pumping Costs in Optimal Operation of Regional Multiquality Water Distribution Systems” by Helena Mala-Jetmarova, Andrew Barton, and Adil Bagirov

Andrew Barton, M.ASCE Senior Lecturer, School of Science, Information Technology, and Engineering, Faculty of Science, Federation Univ. Australia, Mt. Helen Campus, University Dr., Ballarat, VIC 3350, Australia. E-mail: a.barton@ federation.edu.au Adil Bagirov Associate Professor, School of Science, Information Technology, and Engineering, Faculty of Science, Federation Univ. Australia, Mt. Helen Campus, University Dr., Ballarat, VIC 3350, Australia. E-mail: a.bagirov@ federation.edu.au

Plan, Prepare and Safeguard: Water Critical Infrastructure Protection in Australia

Protection of water critical infrastructure in Australia, which has become a significant national objective approached from an all hazard perspective, is presented in this paper. Indeed, threats to Australia’s water critical infrastructure include both all hazard incidents such as bushfires, droughts, floods and others and external human interventions, for example human error, sabotage and terrorism. Water critical infrastructure, originally designed and constructed for ease of maintenance with limited considerations for external adverse interventions, now displays vulnerabilities from those threats. Moreover, as complexity of water infrastructure increases with associated dependency and interdependency on other sectors of critical infrastructures, the consequences of its potential failure also increase. In Australia, planning for water critical infrastructure protection plays a critical role on a national level. This planning aims to ensure that an organisation is prepared to manage and mitigate consequences of an unpredictable incident regardless of its origin. Preparation for water critical infrastructure protection builds on strong cooperative and coordinated relationships between Commonwealth, State or Territory and Local Governments, inclusive of various Government Departments and agencies, represented in public, private and voluntary organisations. Protection of water critical infrastructure is a continual cyclic process consisting of vulnerable asset identification, threat, vulnerability and risk assessments, and protection strategies upgrade. These protection strategies may additionally include business continuity plans and crisis simulation exercises. The Australian model for protecting water critical infrastructure is an evolving process with continual improvements, focussing on planning and preparation with systems in place to anticipate and create a more resilient society for the effective infrastructure protection and assurance of service continuity during any potential crisis.