ISO INTERNATIONAL STANDARD 18400-204 First edition 2017-01 Soil quality - Sampling - Part 204: Guidance on sampling of soil gas Qualitédusol-Echantillonnage- Partie 204: Lignes directrices pour I'echantillonnage des gaz de sol Reference number IS0 18400-204:2017(E) ISO @ISO2017 IS018400-204:2017(E) COPYRIGHTPROTECTEDDOCUMENT IS0 2017, Published in Switzerland All rights reserved. Unless otherwise specified, 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 Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyright@iso.org www.iso.org i IS02017-All rights reserved IS018400-204:2017(E) Contents Page Foreword ..V Introduction. ..vi 1 Scope. 2 Normative references 3 Terms and definitions 4 Preliminary items to be considered 5 Basic principles. .6 5.1 Physical and chemical principles .6 5.1.1 Permanent gases. ..6 5.1.2 Volatile organic compounds .7 5.2 Environmental conditions. 5.3 Soil gas dynamics. .9 5.4 ..9 Identifyingthe sourceof soil gas Requirements for sampling plan. .10 6 6.1 General considerations for sampling plan .10 6.1.1 Objectives and general recommendations .10 6.1.2 Initial explorations (field screening) ..12 6.1.3 Known contamination centre. ..12 6.1.4 Determination ofthe contaminationhot spots (areas showinghighest concentrations)andgasmonitoringwellslocation ..12 6.1.5 Determination of horizontal and vertical distribution of voCs .13 6.1.6 Observation of spatial distribution of voCs in the course of time. .13 6.1.7 Evaluation of soil gases contribution to ambient, indoor and/or outdoor air....13 6.2 Working ranges of measurement methods .13 6.3 Monitoring well options. .14 6.4 Sampling plan. .17 6.4.1 Horizontal location ofsampling devices .17 6.4.2 Monitoring depths. .18 6.4.3 Timing and frequency of monitoring .19 6.4.4 Sample volumes and sampling rates .20 7 Constructionofmonitoringinstallations .21 7.1 .21 General 7.1.1 Environmental conditions 21 7.1.2 Instruments .21 7.2 Soil gas sampling devices 21 7.2.1 Passive soil gas sampling 21 7.2.2 Sub-slab 22 7.2.3 .22 Drivenprobes 7.2.4 Gas-monitoring standpipe in a borehole ..23 Sampling .26 8 8.1 Generic consideration .26 8.2 Preparationofthemonitoringinstallations .29 8.2.1 Preparation ofthe samplingpoint. .29 8.2.2 Leakage test. .29 8.2.3 Purge .29 8.3 Active sampling 30 8.3.1 General .30 8.3.2 Sorbenttubesorfilters 31 8.3.3 Sample containers- Sampling bags .34 一 8.3.4 .35 Sparging. 8.3.5 Samplecontainers— Pressurized containers ..35 @ IS0 2017 -All rights reserved iii