International ISO Standard ISO24511 Activities relating to drinking Second edition 2024-02 water and wastewater services Guidelines for the management of wastewater utilities and for the assessment of wastewater services Activités relatives aux services de I'eau potable et de I'assainissement Lignes directrices pour la gestion des services publics d'assainissement et pour I'évaluation des services fournis Reference number ISO 24511:2024(en) @ ISO 2024 IS0 24511:2024(en) COPYRIGHT PROTECTED DOCUMENT @IS02024 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or Iso's member body in the country ofthe requester. ISO copyright office CP 40i:Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 01 11 Email: [email protected] Website: www.iso.org Published in Switzerland @IS02024-Allrightsreserved i IS0 24511:2024(en) Contents Page @ Foreword. Introduction. .vi 1 Scope. .1 2 Normative references 1 3 Terms and definitions 2 4 Components of wastewater systems 4 4.1 General. 4 4.2 Types of wastewater systems 5 4.3 Centralized systems. 5 4.3.1 Wastewater source. 5 4.3.2 Transport from source to treatment 5 4.3.3 Treatment 4.3.4 Storage, transport and distribution. 7 4.3.5 Disposal of residues. 7 4.4 On-site-systems 7 4.4.1 Wastewater source. 7 4.4.2 Collection and transport. 7 4.4.3 Treatment. 8 4.4.4 Storage, transport and distribution 8 4.5 Disposal or reuse of residues. 8 5 Objectives for the wastewater utility 9 5.1 General 9 5.2 Protection of public health .10 5.3 Meeting users' needs and expectations 11 5.4 Provision of services under normal and emergency situations 11 5.5 Sustainabilityofthewastewaterutility 11 5.6 Promotion of sustainable development of the community 11 5.7 Protection of the environment. 12 5.7.1 Protection of the natural environment. 12 5.7.2 Protection of the built or public environment 12 5.8 Climate change. 12 5.9 Higher user and service demands 13 5.10 Available technologies. 13 6 Management components of a wastewater utility 13 6.1 General 13 6.2 Activities and process management 14 6.3 Resources management. 14 6.4 Asset management... 14 6.5 Customer relations management 15 6.6 Information management. 15 6.7 Environmental management 15 6.8 Risk management.. 15 7 Guidelines for the management of wastewater utilities 16 7.1 General .16 7.2 Organization .17 7.2.1 General. 17 7.2.2 Organizational structure and responsibilities .17 7.2.3 Organization of work flow. 17 7.2.4 Operational documents and records .17 7.3 Planning and construction. .18 7.4 Operations and maintenance.. 19 7.4.1 General .19 @ IS0 2024 - All rights reserved iii IS0 24511:2024(en) 7.4.2 Technical activities .19 7.4.3 Support activities. 20 8 Assessment of wastewater services 22 8.1 General 22 8.2 Assessment policy. 23 8.3 Goal and scope of the assessment. 23 8.4 Partiesinvolvedintheassessment 23 8.5 Methodology of assessment 24 8.6 Service assessment criteria .24 8.7 Resources to conduct the assessment 25 8.8 The production of output and recommendations for the use of the output 25 9 Performance indicators. 25 9.1 General 25 9.2 Performance indicator systems 25 9.2.1 Key components of a performance indicator system 25 9.2.2 Performance indicators 26: 9.2.3 Variables 26 9.2.4 Context information 27 9.3 Quality of the information. .27 9.4 Example of a performance indicator. .27 Annex A (informative) Schematics of wastewater systems .29 Annex B (informative) Possible actions to achieve the objectives of the wastewater utility 31 Annex C (informative) Possible actions related to the management of the wastewater utility .37 Annex D (informative) Example of an assessment methodology for deciding on th