Rita Maria Ugarelli

Field-Oriented Methodology for Real-Time Pressure Control to Reduce Leakage in Water Distribution Networks

AbstractIn this paper, a novel field-oriented methodology to setup real-time control (RTC) for leakage reduction by pressure control valves in water distribution networks is presented. The paper introduces modalities to address the selection of proper RTC system architecture based on the network connectivity at the valve sites. Criteria for target node identification and RTC strategy selection in case of single-control (one valve–one target node) and multiple-control (multiple valve–one target node) architectures are developed. The impact on the control performance of controller calibration and communication protocol selection procedures, and of background noise in pressure signals is also explored. Then, developed criteria and procedures are applied to a Norwegian water distribution network in which a future field-pilot RTC system will be installed. Benefits in terms of pressure control effectiveness and water leakage reduction are evaluated by simulation under different control scenarios as a basic step...

Minimising the total cost of renewal and risk of water infrastructure assets by grouping renewal interventions

Planning the renewal of water infrastructure assets involves balancing the costs of renewal with the costs of risk. A considerable proportion of the renewal budget is spent on planning and mobilising resources to the intervention location. One may therefore reap benefits from the economies of scale by grouping the renewal of water mains which are spatially close. If one can express the total cost of renewal, risk and unavailability of a water main as a function of time, one may use this to find an optimal configuration of groups to be renewed together, where the benefits of grouping are balanced with the costs of shifting renewal investments in time. This paper demonstrates a methodology for optimising the grouping of renewals of connected water mains. The methodology is applied both to obtain an optimal set of groups for all mains in the network, as well as considering the contingency of renewing a group of mains in the event of a pipe burst. The methodology has been demonstrated with a case study, where the costs of leakage, and structural and hydraulic reliability are considered. The results show that there can be considerable monetary savings made by grouping the renewal of water mains.

Performance-based modelling of long-term deterioration to support rehabilitation and investment decisions in drinking water distribution systems

Abstract Managing the urban drinking water system in the long term in order to maintain system performance can be challenging due to the difficulty of modelling future deterioration of the networks. This paper establishes a methodology for cohort survival models where historical (empirical) data on decommissioning ages of pipes are used to calibrate survival functions of pipe cohorts according to service level targets. The benefit of the approach is that remaining useful life of pipes, future renewal rates and investment needs can be governed by a required level of service in the network. A case study shows how the methodology can be applied to a cohort of drinking water pipes to create a ‘calibration curve’, which is a survival function calibrated with empirical data.

Investigation of the Ability to Accurately Estimate Background Leakage Parameters in WDS Network Simulation Models

AbstractHydraulic models that include background leakage estimates can be used to support effective decision-making aimed at reducing leakage levels and improve the understanding of the leakage hyd...

Improving data collection strategies and infrastructure asset management tool utilisation through cost benefit considerations

Infrastructure asset management (IAM) depends on systematic data management to support its processes. Data collection and management can be costly, and it is therefore important to utilise data efficiently – however, it is not always straightforward to evaluate the benefits of data collection. This paper proposes a methodology for assessing the cost-benefit relationship between data collection and data utilisation for IAM tools. In this methodology, the costs are expressed as the work hours invested in collecting the data, while the benefits are expressed as informational outcomes. The methodology has been developed in a spreadsheet, and is demonstrated in a real water utility. This paper shows how the methodology can be used by a utility to assess its current cost-benefit situation for their IAM data, and utilise the cost-benefit results to improve the information effectiveness of its IAM tools.