Introduction

This document is written within the overall concept of asset management which is an activity all organizations undertake in some manner and to some degree. It focusses on the details of managing the physical assets at the operational level rather than the organizational (corporate management) level.

Water services are reliant on their assets to deliver their services to the resident populations in their jurisdictions. The assets (underground pipes, reservoirs, storage tanks, treatment plants, etc.) collectively form the physical infrastructure of the water services and are the consequence of the accumulated capital investments and operational expenditures on maintenance and rehabilitation over many years. In many of these services, the replacement value of these past investments amounts to many millions (even billions) of dollars depending on the size of the community served. Therefore, the infrastructure represents a major societal investment in essential services contributing to public health and the protection of the environment.

In many countries, these assets have been identified as critical infrastructures and programs are in place to assure their protection or their sustainability. Like many other organizations having assets, water services undertake programs of activities to manage the assets to ensure they continue to meet the needs of the community for reliable delivery of potable water. These management activities can be at the strategic, tactical or operational level. The activities can be part of a formal management system, or the result of specific legislative requirements, or ultimately just the result of due diligence by the service operators and managers.

This document is expected to serve as a supporting document for utilities operating management of assets in accordance with ISO 24516.

In many countries there is a sustainability problem, sometimes referred to as the infrastructure gap: for various reasons, the infrastructure has not been maintained over the years on a truly sustainable basis, in other words funding of rehabilitation and replacement programs has been postponed, with a focus instead on short term repairs, or an allowed decrease in the level of service provided.

The condition of water infrastructures greatly influences the adequacy of the water service, specifically its quantity, pressure, quality, safety, reliability, environmentally friendly, degree of purification and economic efficiency. System condition-based rehabilitation approaches serve to meet these requirements with a focus on a holistic approach of condition-based, risk-oriented maintenance.

Once the installation and development of water assets is almost completed, the optimization of networks will become necessary in many places in order to respond to changing societal and economic conditions. Networks are subject not only to ageing as well as wear and tear, but also to adaptation processes resulting from growth, new legislative requirements, or changing customer service level expectations. This requires water utilities to focus increasingly on the growing need to rehabilitate existing water networks rather than removing and replacing the networks. Rehabilitation will thus become essential in asset management, with ever more stringent requirements on the design and execution of rehabilitation.

In recent years, much effort has been applied to the whole issue of asset management on two levels: what are the principles and structure of an asset management system, and what are the good practices that can be implemented on a technical level to assess the condition of the assets and help decide when asset interventions (repair, rehabilitation or replacement) take place.

This document offers examples on how to define an asset management strategy with regard to the overall performance expected by the owner. It includes several aspects of the operations and maintenance, including asset condition assessment and investment (new assets, rehabilitation and renewal) strategies.

The focus will be on the following selected activities of the management of assets of wastewater systems as addressed in ISO 24516‑2 and ISO 24516‑4).

— Clause 4 covers the principal aspects of the management of assets, including examples of:
1. — objectives;
2. — strategies;
3. — structure of the process.
— Clause 5 covers the tools and methods for investigation, including operational data collection, tools for diagnosis, other source of information along with key practical recommendations for implementation and analysis of closed-circuit television (CCTV) investigation.
— Clause 6 covers the assessment of the system against its performance expectations for the following aspects:
1. — practical tools and methods for structural, functional, hydraulic performance;
2. — examples of degradation factors and models of degradation;
3. — practical tools and methods for criticality assessment;
4. — examples of calculation to assess the likelihood of a failure.
— Clause 7 covers the implementation of sustainable field works, providing examples of what matters from asset management point of view.
— Clause 8 covers the operation and maintenance by providing examples of monitoring and controlling flow and quality, measuring combined overflow quantity and quality, cleaning and removal of obstructions to restore hydraulic capacity, energy management, monitoring and control and maintenance of civil structures.
— Clause 9 covers the prioritization of rehabilitation of assets with examples of how it is done practically.

The examples of good practice for asset management of wastewater systems covered in this document are relevant to all types and sizes of organization and utilities operating wastewater systems.

PD ISO/TR 24589-2:2025

Examples of good practice for the management of assets of water supply and wastewater systems - Wastewater systems

Current

Published:

30 Jun 2025