ISO INTERNATIONAL STANDARD 18400-204 First edition 2017-01 Soil quality - Sampling - Part 204: Guidance on sampling of soil gas Qualité du sol - Echantillonnage - Partie 204: Lignes directrices pour I'eéchantillonnage des gaz de sol Reference number IS0 18400-204:2017(E) International Organization for Standardization ee=ZHEJIANG INST OF STANDARDIZATION C1 5956617 @ IS0 2017 mitted without license from IHS IS0 18400-204:2017(E) COPYRIGHT PROTECTEDDOCUMENT 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 +4122 749 09 47 copyright@iso.org www.iso.org Licensee-ZHEJIANG INST OF STANDARDIzRoISQ 7 - All rights reserved Not for Resale, 2017/3/28 02:55:54 networking permited without license from IHS IS0 18400-204:2017(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 Identifying the source of soil gas .9 6 Requirements for sampling plan... ..10 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 of the contamination hot spots (areas showing highest concentrations) and gas monitoring wells location ..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 of sampling 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 Construction of monitoring installations .21 7.1 General 21 7.1.1 Environmentalconditions 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 Driven probes 22 7.2.4 Gas-monitoring standpipe in a borehole 23 8 Sampling. .26 8.1 Generic consideration .26 8.2 Preparation of the monitoring installations 29 8.2.1 Preparation of the sampling point. .29 8.2.2 Leakagetest 29 8.2.3 Purge 29 8.3 Active sampling 30 8.3.1 General 30 8.3.2 Sorbent tubes or filters. 31 8.3.3 Sample containers - Sampling bags ..34 8.3.4 Sparging. 35 8.3.5 Sample containers - Pressurized containers 35 ntemaional ganzationS27-All rights reserved ii Licensee=ZHEJIANG INST OF STANDARDIZATION C1 5956617 vided by IHS under license with ISC ted without license from IHS