ISO/TR TECHNICAL REPORT 24524 First edition 2019-02 Service activities relating to drinking water supply, wastewater and stormwater systems Hydraulic, mechanical and environmental conditions in wastewater transport systems Reference number IS0/TR24524:2019(E) ISO @ IS0 2019 IS0/TR24524:2019(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: [email protected] Website: www.iso.org Published in Switzerland ii @ IS0 2019 - All rights reserved IS0/TR24524:2019(E) Contents Page Foreword ..iv Introduction. .. 1 Scope. 2 Normative references 3 Terms and definitions 4 Toilets.. ..2 4.1 General. .2 4.2 Typical toilet types .2 4.3 Usage patterns. ..3 5 Drain lines .3 5.1 General .3 5.2 Drain line hydraulic conditions - intermittent flow .3 5.2.1 General .3 5.2.2 Drain line clearance stranding 3 5.2.3 Drain line clearance - settling ..4 5.2.4 Drain line clearance snagging .4 5.3 Typical drain line configurations .4 6 Wastewater transport systems ..5 6.1 General. .5 6.2 Typical transit times in transport systems .6 6.3 Typical hydraulic conditions in flowing pipes (Reynolds number) .6 7 Screening. ..6 8 Treatment processes ..6 8.1 General .6 8.2 Settlement. ..7 8.3 Liquid phase of treatment plants .1 8.4 Biodegradation of settled solids 7 9 Environmental considerations .7 Bibliography .8 @ IS0 2019 - All rights reserved iii