ISO/TS TECHNICAL SPECIFICATION 24522 First edition 2019-02 Event detection process: Guidelines for water and wastewater utilities Reference number IS0/TS 24522:2019(E) ISO IS02019 IS0/TS 24522:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ ISO 2019 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 of the requester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +4122 749 0111 Fax: +41 22 749 09 47 Email: copyright@iso.org Website: www.iso.org Published in Switzerland ii @ IS0 2019 - All rights reserved IS0/TS24522:2019(E) Contents Page Foreword ..V Introduction. ...vi 1 Scope. 2 Normative references 3 Terms and definitions 4 Principles of an event detection process .5 4.1 Design phase. .5 4.1.1 General. 4.1.2 Influence matrix table and EDP .6 4.1.3 EDPinputs. 4.1.4 EDP design 7 4.1.5 EDP target service level design 4.2 Detection phase ..8 4.2.1 General ..8 4.2.2 Validation process .8 4.2.3 Further event monitoring .9 4.3 Ongoing activities. .9 4.3.1 Post-event EDP evaluation .9 4.3.2 Periodic reviews 4.3.3 Validation of links between phenomena and risk materialization. ..10 4.3.4 Estimation. .10 4.3.5 Decision-making ..10 4.3.6 Guidance on interpretation ..10 5 The event detection cycle and the role of the EDP ..10 5.1 The EDP's application of the event detection cycle (the EDP cycle). ..10 5.2 Development and regular review of an EDP-based event detection capability. ..11 5.2.1 General ..11 5.2.2 Listing of possible event indicators .12 5.2.3 IMT establishment. .12 5.2.4 EIT establishment ..12 5.2.5 IMT and EIT periodic review. ..12 5.3 Deployment of an event detection procedure. ..12 5.3.1 General. ..12 5.3.2 Defining the possibility of an event's occurrenc .13 5.3.3 Nature of water/wastewater measurement sampling considerations. ..13 5.3.4 Results assessment. ..13 5.3.5 Missing inputs. .14 5.3.6 Unfamiliar combination of inputs ..14 5.3.7 Deviation from normal frequency detection .14 5.3.8 Measurement grouping. ..14 5.4 Classification of events and evaluation of the classification procedure ..14 5.4.1 General ..14 5.4.2 Process-based classification. ..15 5.4.3 Actualclassification .15 5.4.4 Assignment of weights. ..16 5.4.5 Frequency calculations ..16 5.4.6 Classification efficiency estimation ..16 5.4.7 Classification evaluation .16 5.5 Notification to relevant personnel/systems ..16 5.6 Documentation of events ..16 5.6.1 General. ..16 5.6.2 Time stamps. ..17 @ IS0 2019 - All rights reserved iii