INTERNATIONAL STANDARD ISO 18400-204 First edition 2017-01 Soil quality — Sampling — Part 204: Guidance on sampling of soil gas Qualité du sol — Échantillonnage — Partie 204: Lignes directrices pour l’échantillonnage des gaz de sol Reference number ISO 18400-204:2017(E) © ISO 2017 ISO 18400-204:2017(E) COPYRIGHT PROTECTED DOCUMENT © ISO 2017, Published in Switzerland All rights reserved Unless otherwise specified, no part o f 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 o f the requester ISO copyright o ffice Ch de Blandonnet • 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 ii © ISO 2017 – All rights reserved ISO 18400-204:2017(E) Page Contents Foreword v Introduction vi Scope Normative references Terms and definitions Preliminary items to be considered Basic principles 5.2 5 I denti ying the s o urce o s o il gas General considerations for sampling plan 10 6.1.1 Objectives and general recommendations 10 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 Working ranges of measurement methods 13 Monitoring well options 14 Sampling plan 17 6.4.1 Horizontal location of sampling devices 17 6.4.2 Monitoring depths 18 f f 19 6.4.4 Sample volumes and sampling rates 20 6.1 I nitial exp lo ratio ns (field s creening) Timing and requency o mo nito ring Construction of monitoring installations 21 7.1 7.2 S o il gas dynamics Requirements for sampling plan 10 6.1 6.2 6.3 6.4 5.1.1 Permanent gases 5.1.2 Volatile organic compounds Environmental conditions f f Phys ical and chemical p rincip les General 21 7.1.1 Environmental conditions 21 7.1.2 Instruments 21 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 Sampling 26 8.1 8.2 8.3 Generic consideration 26 Preparation of the monitoring installations 29 8.2.1 Preparation of the sampling point 29 8.2.2 Leakage test 29 8.2.3 Purge 29 Active sampling 30 8.3.1 General 30 31 8.3.3 Sample containers — Sampling bags 34 8.3.4 Sparging 35 8.3.5 Sample containers — Pressurized containers 35 8.3 S o rb ent tub es o r filters © ISO 2017 – All rights reserved iii ISO 18400-204:2017(E) 8.4 8.5 Passive sampling 35 Sampling for on-site measurements 36 f f 37 37 9.2 Packaging and transport 37 Sampling report 37 Quality assurance 38 11.1 General 38 39 11.2.1 General 39 11.2.2 Blind replicate samples 40 11.2.3 Split samples 40 11.2.4 Trip blanks 40 11.2.5 Field blanks 40 40 f 40 f 41 11.2.9 Equipment 41 11.3 Interferences 42 11.3.1 General 42 11.3.2 Large sample volume 42 11.3.3 Cohesive soils 42 11.3.4 Soil moisture 42 11.3.5 Low ambient temperatures 42 42 11.3.7 Seepage front 42 11.3.8 Perched water table horizon 43 11.3.9 Contamination 43 11.3.10 Breakthrough 43 f f 43 I 10 11 d e n t i f i c a t i o n , p a c k a g i n g a n d 9.1 I dentificatio n 1 Quality co ntro l s amp les 1 t r a n s p o r t o 1 O ther quality co ntro l s amp les 1 Evaluatio n o 1 C hain o 1 H etero geneo us s tratigrap hy s a m p l e s o r l a b o r a t o r y a n a l y s i s quality co ntro l s amp le res ults cus to dy I nterp retatio n o s o il gas analys es (informative) o r VO C s Annex A Standard equipment and instruments used for soil gas sampling for VOCs 44 (informative) Portable equipment to measure gases 46 48 Annex C (informative) Annex D (informative) f 50 Annex B E B i iv b l i o g r a p h y q E u x a i p m m p l e e n t o t o s a m m e a p l s i u n r e g s f l h o e w e r a t e s a n d b o r e h o l e p r e s s u r e t 52 © ISO 2017 – All rights reserved ISO 18400-204:2017(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies) The work o f preparing International Standards is normally carried out through ISO technical committees Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters o f electrotechnical standardization The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part In particular the different approval criteria needed for the di fferent types o f ISO documents should be noted This document was dra fted in accordance with the editorial rules of the ISO/IEC Directives, Part (see www.iso org/directives) Attention is drawn to the possibility that some o f the elements o f this document may be the subject o f patent rights ISO shall not be held responsible for identi fying any or all such patent rights Details o f any patent rights identified during the development o f the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso org/patents) Any trade name used in this document is in formation given for the convenience o f users and does not constitute an endorsement For an explanation on the meaning o f ISO specific terms and expressions related to formity assessment, as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso org/iso/foreword.html This document was prepared by Technical Committee ISO/TC 190, Soil quality, Subcommittee SC 2, Sampling This first edition o f ISO 18400-204 cancels and replaces ISO 10381-7:2005, which has been technically and structurally revised The ISO 18400 series is based on a modular structure and cannot be compared to ISO 10381-7 clause by clause A list of all parts in the ISO 18400 series can be found on the ISO website © ISO 2017 – All rights reserved v ISO 18400-204:2017(E) Introduction This document is one of a group of International Standards to be used in conjunction with each other f f investigation The roles/positions of the individual standards within the total investigation programme are shown in Figure where ne ce s s ar y T he I S O 0 s erie s de a l s with s ampl i ng pro ce du re s or the variou s pu rp o s e s o s oi l T he s tate d s oi l ga s a nd la nd fi l l- ga s me as u rements no t give any quantitative s tatement o f the to ta l quantity o f materia l de te c te d i n s oi l ga s or s oi l T he me as u rement re s u lts c an b e i n fluence d b y, e g temp eratu re, hu m id ity, r pre s s ure, m i n i mu m e xtrac tion dep th, e tc T he genera l term i nolo g y used is in accordance with th at e s tabl i she d in I S O/ TC 19 and, more p ar tic u l arly, with the vo c abu la r y given i n I S O 10 74 Toxic, a s phyxiati ng a nd e xp lo s ive s oi l gas e s c an enter bu i ld i ngs and o ther bui lt development on and b elow grou nd and variou s ly p o s e p o tentia l ri s ks to o cc up a nts a nd u s ers and to the s truc tu re s themselves Such ga s e s m ight b e pre s ent i n the grou nd natu l ly, or b e pre s ent as a re s u lt o f conta m i nation o f the ground, or arise from buried wastes In addition to the main components found in air (nitrogen and ox ygen) , s oi l ga s c a n conta i n volati le orga n ic comp ou nd s ( VO C s) , i norgan ic vap ours (e g merc u r y) and a wide nge o f o ther ga s e s (e g me tha ne, c a rb on d ioxide, c arb on monoxide, hyd ro gen s u l fide, am mon i a, helium, neon, argon, xenon, radon, etc.) T he s e gas e s c a n have s evera l origi n s s uch as: l and fi l le d was te s; contam i nate d s oi l s on a brown field s ite; plu me o f contam i nate d grou ndwater; s pi l l or le a kage o f chem ic a l s pro duc ts , le a ks o f ma i n s gas (natu l gas) ; s ewer gas , e tc I n order to complete an as ses s ment o f the risks p os ed by the presence o f p ermanent and other soi l gas es li ke VO C s , it is neces s ar y to unders tand and charac teri ze the p otential s ources o f gas in and around a s ite Guidance on installations for soil gas sampling (equipment and instruments, methods of sampling, requirements of controls, etc.) and other relevant information (e.g on environmental conditions) are provided in this document vi © ISO 2017 – All rights reserved ISO 18400-204:2017(E) F NOTE NOTE i g u r e — L i n k s b e t w e e n t h e e The numbers in circles in Figure Figure s s e n t i a l e l e m e n t s o f a n i n v e s t i g a t i o n p r o g r a m m e de fi ne the ke y elements (1 to ) o f the i nve s tigatio n p ro gra m me d i s p l ays a gener ic pro ce s s wh ich c a n b e a mende d when ne ce s s a r y © ISO 2017 – All rights reserved vii INTERNATIONAL STANDARD ISO 18400-204:2017(E) Soil quality — Sampling — Part 204: Guidance on sampling of soil gas Scope This document contains guidance on soil gas sampling using — ac tive s ampl i ng (ad s orb ents , fi lters , r contai ners) , a nd — passive sampling app l ie d at p ermanent or temp orar y mon itori ng wel l s buildings (sub-slab) It provides guidance on: — development o f a s ampl i ng pla n; — s truc tion o f mon itori ng i n s ta l lation s; — tran s p or t, p ackagi ng a nd s torage s oi l gas s ample s; — qua l ity a s s u rance or o ther i n s ta l lation s i n s oi l s or u nderne ath This document also gives basic information about — s oi l ga s dynam ics , a nd — identi fic ation o f s oi l gas s ou rce s relevant to p erma nent or temp orar y b orehole s i n s oi l s or underne ath bu i ld i ngs (s ub - s lab) T he comp ou nd s covere d b y th i s c u ment a re: — vol ati le organ ic comp ou nd s ( VO C s) ; — i norga n ic vol ati le comp ou nd s (e g merc u r y, HC N ) ; — permanent gases (i.e CO2 , N2 , O2 , CH4) This document does not give guidance on: — ri s k eva luation and ch arac teri z ation; — s ele c tion a nd de s ign o f pro te c tive me as u re s; — the veri fic ation o f pro te c tive me as u re s , a lthough the s ite i nve s tigation me tho dolo gie s de s c rib e d c a n b e u s e d when appropri ate; — the s ampl i ng o f atmo s pheric or i ndo or ga s e s; — the me a s u rement o f gas e s from the s oi l enteri ng i nto the atmo s phere; — monitoring and sampling for radon © ISO 2017 – All rights reserved ISO 18400-204:2017(E) T he Normative references fol lowi ng c u ments are re ferre d to i n the te xt i n s uch a way that s ome or a l l o f thei r content s titute s re qu i rements o f th i s c u ment For date d re ference s , on ly the e d ition c ite d appl ie s For undate d re ference s , the l ate s t e d ition o f the re ference d c u ment (i nclud i ng a ny amend ments) appl ie s ISO 11074, Soil quality — Vocabulary ISO 18400-107, Soil quality — Sampling — Part 107: Recording and reporting Terms and definitions For the pu rp o s e s o f th i s c u ment, the term s and defi n ition s given i n I S O 110 74 and the fol lowi ng apply ISO and IEC maintain terminological databases for use in standardization at the following addresses: — IEC Electropedia: available at http://www.electropedia org/ — ISO Online browsing platform: available at http://www.iso org/obp 3.1 active soil gas sampling s a mpl i ng b y ex trac ti ng a cer tai n volu me o f s oi l gas 3.2 breakthrough detection of an adsorbent control section of one or more compounds having a mass greater than % of the ma s s quanti fie d on the me as u ri ng s e c tion 3.3 dead volume volume which is present between the suction opening of the soil gas probe and the sampling vial, including the volume of the sampling vial or of the adsorption tube 3.4 dense non aqueous phase liquid DNAPL liquid o f a group o f organic s ubs tances which is relatively insoluble in the water and denser than the water 3.5 direct method direct measuring method me tho d o f ana lys i s where the s oi l ga s s a mp le (a l iquo t) i s d i re c tly i ntro duce d i nto a s u itab le e qu ipment without fi rs t b ei ng concentrate d and s ubj e c te d to a na lys i s 3.6 direct-reading detecting tube glas s tub e fi l le d with re agents wh ich, a fter d rawi ng th rough cer tai n gas e ou s comp ou nd s , s how concentration-dependent chromophoric reactions and which are thus used for qualitative and semiqua ntitative ana lys e s a s wel l N o te to entr y: I t i s i mp o r ta nt th at attentio n b e p a id to c ro s s - s en s itivitie s 3.7 gas migration movement of gas from the source through the ground to the adjoining strata or to emit to atmosphere N o te to entr y: E xa mp le s o f s ou rce s i nclude e g wa s te s with i n a l a nd fi l l o r s p i l l o f hyd ro c a rb o n s © ISO 2017 – All rights reserved ISO 18400-204:2017(E) 11.2.2 Blind replicate samples T he s e s ample s c a n b e u s e d to identi fy the va riation i n a na lyte concentration b e twe en s ample s col le c te d from the s a me s a mp l i ng p oi nt and/or the rep e atabi l ity o f the l ab orator y’s ana lys i s For ever y samples taken, one set of blind samples should be collected These samples should be submitted to the lab orator y as two i nd ividua l s ample s a nd no i nd ic ation given that they a re dupl ic ate s 11.2.3 Split samples T he s e s ample s provide a che ck on the ana lytic a l pro ficienc y o f the lab oratorie s For ever y s a mple s , one set of split samples should be taken The split samples should be set in parallel, from the same sampling point in a single operation One sample from each set should be submitted to a different lab orator y for a na lys i s T he s a me ana lyte s s hou ld b e de term i ne d b y b o th lab oratorie s , u s i ng identic a l ana lytic a l te ch n ique s NO TE 1 I n co m mo n s tud ie s , T r i p b l a n for m a ny re a s on s (ti me , flow, e tc ) , s p l it s a mp le s a re rel y ta ken a nd a n a l yz e d k s These blanks are used to detect cross-contamination of samples during transport A container or sorbent cartridge or other collection medium, identical to the ones being used for the samples, is sealed as for a re a l s a mple, p lace d with the s ample s and tran s p or te d b ack to the lab orator y No pumping will be applied on trip blanks It is essential that trip blanks are packaged in the same conditions as the other samples in order to be able to d raw conclu s ion s ab out p o s s ible i n fluence s o f the contai ner on the ad s orb ent tub e s (s o the tub e shou ld b e c app e d du ri ng tran s p or tation i n the s ame way as the o ther tub e s) T he trip b lan k i s then ana lys e d a long with the col le c te d s ample s 1 F i e l d b l a n k s These blanks are used to detect cross contamination of samples during sampling The blank tubes f the pumping phase and then reopened whilst the actual sampling tubes are being removed from the are op ene d at the s ame ti me as the tub e s to b e u s e d or the ac tua l s ampl i ng T hey a re clo s e d du ri ng s a mpl i ng trai n No pu mpi ng i s done on field bl an ks T he field bla n ks wi l l b e fi na l ly clo s e d and p acke d i n the co oler b ox a s a s e t o f s ample tub e s I t i s e s s enti a l that the field b lan ks a re p ackage d i n the s ame cond ition s a s the o ther s ample s to b e able to d raw conclu s ion s ab out p o s s ible i n fluence o f field cond ition s on the s ample s T he field bl an k i s then ana lyz e d a long with the col le c te d s a mple s 1 O t h e r q u a l i t y c o n t r o l s a m p l e s O ther qua l ity control s a mple s to b e s idere d i nclude re s ubm i s s ion o f a previou s ly ana lys e d s ample to the s ame l ab orator y or to a d i fferent lab orator y 11.2.7 Evaluation of quality control sample results T he ana lytic a l re s u lts a nd qua l ity control data shou ld b e eva luate d fol lowi ng re co gni z e d pro ce du re s to a l low the i nterpre tation o f acc urac y, pre c i s ion and repre s entativene s s o f the data Typic a l va ri ation s wh ich c a n b e e xp e c te d 40 from accep table qua l ity control s ample s a re s hown i n Table © ISO 2017 – All rights reserved ISO 18400-204:2017(E) Table — Acceptance criteria for quality control samples Quality control samples Minimum number of samples Blind replicate sample One per 20 samples collected Split sample One per 20 samples collected Typical RPD for quality control samples a,b 30 % to 50 % of mean concentration o f analyte 30 % to 50 % of mean concentration o f analyte determined by both laboratories c The significance o f the trip blank Trip blank should be evaluated in One per box used to contain samples results terms of those obtained for the Field blank One per day a actual field samples The significance o f the field blank results should be evaluated in terms of those obtained for the actual field samples The relative percent di fference (RPD) is [(relative di fference between two samples expected to be similar) divided by the mean result] times 100 b The significance o f the RPDs o f the results should be evaluated on the basis o f sampling technique, sample variability and absolute concentration relative to criteria and laboratory per formance c This variation can be expected to be higher for organic analytes than for inorganic and low concentration analytes 1 C h a i n o f c u s t o d y This process details the links in the transfer of samples between the time of collection and their arrival at the laboratory Several trans fers can take place in this process, but details o f each trans fer should be recorded on a chain o f custody form The minimum in formation that shall be included on the form is the following: a) name o f the person trans ferring the samples; b) time and date that samples are taken; c) time and date that samples are received by the laboratory; d) analytes to be determined; e) other specific instructions in the handling o f the samples during analysis, e.g special sa fety precautions; f ) samples that are expected to contain high levels o f the analyte in question or other substances that can inter fere with the analysis 11.2.9 Equipment All equipment should be calibrated and demonstrated to meet the calibration specifications prior to use There are a number of reasons for this: a) gas analysers have a tendency to dri ft over time; b) some instrument types have a limited li fe and can fail suddenly without warning; c) landfill gas contains trace gases that can “poison” the monitoring equipment The instrument should be calibrated using a standard gas with appropriate concentration and a zero gas such as nitrogen The frequency o f calibration will depend on how regularly the instrument is used Advice on how to carry out calibration should be provided with the instrument Regular servicing should be carried out according to the manufacturer’s recommendations Regardless of whether the © ISO 2017 – All rights reserved 41 ISO 18400-204:2017(E) calibration is performed off-site or on-site, all calibration data should be recorded and made available on request Off-site calibrations are not suitable for instruments recording changes during transportation 11.3 Interferences 11.3.1 General Soil gas measurement can be influenced by various inter ferences, which can lead to errors or misinterpretations 11.3.2 Large sample volume The larger the sample volume, the more likely is the ingress o f ambient air, especially when sampling close to the sur face In such instances, there is insu fficient protection against the influence o f ambient air especially in highly permeable ground As the sample volume can have a significant influence on the measurement results, techniques that employ small sample volumes are generally recommended 11.3.3 Cohesive soils With strongly cohesive soils it may not be possible to achieve the required sample volume In such conditions, soil gas measurements are not representative 11.3.4 Soil moisture Soil moisture can interfere with the adsorption of the organic substances onto the collection matrix If the pore spaces at the bottom of the borehole are saturated with soil moisture (e.g due to an impermeable layer), sampling from the subsoil o f the borehole is not possible The pump is turned o ff for some sampling systems when the moisture content is too high 11.3.5 Low ambient temperatures The sampling o f soil gas at ambient temperatures, which are clearly lower than that o f the soil gas (e.g frost), can lead to spuriously low estimates o f volatile organic substances due to condensation in cold spots o f the sampling system NOTE I f ambient temperatures are clearly lower than that o f the soil gas, the sampling devices (absorption tube, syringe, direct reading tube) can be placed within the monitoring well i f it is not in contact with the inner wall of the pipe NOTE I f ambient temperatures are clearly lower than that o f the soil gas, the sampling devices (absorption tube, syringe, direct reading tube) can be protected with thermal insulation material, or can be heated at a temperature slightly above soil gas temperature 11.3.6 Heterogeneous stratigraphy The adherence to a constant sampling depth without taking into account the orientation o f strata yields di fferent results, irrespective o f the e ffective pollutant contents in the soil There fore, only measuring results from the same soil layers should be related to each other i f heterogeneous stratigraphy is discovered 11.3.7 Seepage front A fter strong rains or floods, soil layers may have been washed through, leading to lowered recoveries in soil-gas samples taken above the seepage front Water infiltration may also hinder the volatilisation o f volatile compounds, disturb gas equilibrium in soil, and block the flow o f pore gas 42 © ISO 2017 – All rights reserved ISO 18400-204:2017(E) 11.3.8 Perched water table horizon I n th i s c as e, s p e c i fic attention s l l b e p aye d to the water contam i nation when the wel l i s d ri l le d No strainers shall be placed in front of perched water table horizon Water absence in the borehole shall be s tric tly che cke d b e fore s ampl i ng s tep s 11.3.9 Contamination E ver y event or ob s er vation that may c au s e u ncer ta i ntie s or contam i nation o f s a mple s sha l l b e i nd ic ate d on the sampling report (e.g stopping of pump after a known duration or not, non-tightness sampling line, defective casing, leaks of the monitoring well, observation of moisture on the tubes or media) This i n formation shou ld b e provide d i n fu l l tra n s p arenc y i n order to a l low acc u rate i nterpre tation o f the ana lytic a l re s u lts To avoid contamination, the following precautions shall be followed: — s tore s ampl i ng me d ia on ly i n thei r s p e ci fic contai ners; — no t s moke when hand l i ng s ample s; — use latex gloves when handling samples 11.3.10 Breakthrough Breakthrough testing comprises joining two sorbent tubes in series, as close together as possible, before undertaking sampling, or using adsorbent tubes including a front section and a back section f back tube (closest to the pump) The front section is the measuring section and the back section is the control section If one or more compounds are detected on the back tube (or back section) at a mass higher than % of the mass detected on the front tube (or front section) for one or more compounds, the front tube is deemed of compounds present in the soil gas So, the sampling will not be considered representative When the total mass of compounds on the control section is higher than % of the total mass of the compounds on the measuring section, the sample is considered unrepresentative In fact, the actual concentrations can be greater than the sum of the concentrations of the two sections Sub s e quent l ab orator y a na lys i s i s c a rrie d out on b o th the ront tub e (clo s e s t to the s ampl i ng p oi nt) a nd to have b e en over- s atu rate d with the p o tenti a l that the ana lys i s wi l l under-pre d ic t the concentration When the ma s s o f a comp ou nd i n the control layer i s gre ater tha n % o f the ma s s o f the s ame comp ou nd on the me a s u ri ng s e c tion, the s ample i s s idere d i nva l id for th i s comp ou nd on ly Rep e at s ampl i ng i s ne e de d , u s i ng either a lower flow rate and/or lower s a mpl i ng ti me to demon s trate that tube saturation is not occurring 11.4 Interpretation of soil gas analyses for VOCs T he re s u lts ob tai ne d sampling conditions from d i fferent s ampl i ng me tho d s a re no t d i re c tly comp a rable due to va ri ation s i n S oi l ga s i nve s tigation s p er forme d on ly once (and a s s um i ng th at a l l ne ce s s a r y as p e c ts have b e en ta ken into account) represent the conditions available at the time of sampling A change in the concentration f concentrations in soil gas In the case of soil gas components that are not bound to liquid medium in soil (in particular groundwater), their relative distributions over time in response to variables (such as and ph as e e qu i l ibri a i n s oi l over ti me wi l l re s u lt i n ch ange s i n the d i s tribution and i nten s ity o s ub s ta nce d i re c tion, nge, i nten s ity, comp o s ition) sh a l l a l s o b e s idere d © ISO 2017 – All rights reserved 43 ISO 18400-204:2017(E) Annex A (informative) Standard equipment and instruments used for soil gas sampling for VOCs D e fi n ition o f the e qu ip ment or i n s tr u ment to u s e mu s t ta ke i nto accou nt r i s ks o f e xp lo s ive atmo s p here NO TE Table A.1 lists the standard equipment/instruments that are used for soil gas sampling for VOCs Table A.1 — Standard equipment and instruments used for soil gas sampling for VOCs E q u i p m e n t / i n s t r u m e n t a n d p u r p o s e R e q u i r e m e n t s , l i m i t s o f a p p l i c a t i o n Electric hammers for driving down soil gas Possible contamination due to exhaust air, petrol and oil from probes and installing boreholes using window petrol-fuelled engines shall be avoided sampler f f f wind direction equipment I n s ta l l atio n o G enerator generato r at s u fic ient d i s ta nce a nd i n s u itab le o r o p erati ng ele c tr ic a l l y d r iven J ack ( hyd rau l ic or me ch a n ic a l ) E le c tr ic a l l y d r iven h a m mer or core d r i l l i ng instrument for boring through sealed or solidifie d s u r face s S tab le , temp eratu re re s i s ta nt, i ner t (s ta i n le s s s te el) , e a s y to o p erate , ga s -tight e x tend ib le , e a s y to cle a n , known de ad vol Soil gas probes - u me , de fi ne d clo s e op en i ng a re a S a mp l i n g he ad with s ep tu m , i f ne ce s s a r y Connection of gas dosage valve to probe head to make direct me a s u rements u s i n g a ga s ch ro m ato grap h , i f ne ce s s a r y C ontrol l ab le acco rd i n g to vo lu me flow, p o s s ib l y with conti nu Pump for extraction of soil gas o u s l y adj u s tab le for d i ne d b y the p u mp flow) When using direct-reading detector tubes, the appropriate b el lows vac uu m tub e Manometer (if not integrated in pump) Volu me flowme ter - i n fluence rad iu s e xp e c te d (vo lu me o f s o i l for the de te c to r tub e typ e For measuring the negative pressure developing during soil gas sampling e.g gas meter to measure sampling volume va r i ab le a re a flowme ter to control volu me flow Water s ep a rato r, i f ne ce s s a r y Sampling devices e g Wu l ff fl a s k e.g Pasteur pipettes, rimmed vials with PTFE-lined septa (head-space glasses, volume 10 ml or 20 ml, these septa shall s el f- s e a l a fter i n s er tio n a nd withd rawa l o f s yr i nge) Sampling devices and, if required, closures shall be heated p r ior to u s e to avoid the c a r r y- o ver o f co nta m i n atio n Cartridge (butane) with burner Closure indicator for rimmed vials 44 S o - c a l le d a i r- b ags a re no t s u itab le for a n a l ys i ng VO C s To melt end o f s a mp le -fi l le d P a s teu r pip e tte s For gas-tight fastening of septa on ampoules using aluminium seal rings © ISO 2017 – All rights reserved ISO 18400-204:2017(E) Table A.1 (continued) E q u i p m e n t / i n s t r u m e n t a n d p u r p o s e Adsorption tube with protective tube Gl a s s s yr i nge Evacuation equipment (negative pressure R e q u i r e m e n t s , l i m i t s o f a p p l i c a t i o n Filled with activated charcoal, carbon molecular sieves, grap h iti z e d c a rb o n , re s i n , p oro u s p ol ymer Gas-tight sealable protective tube for transport and storage Gas-tight p u mp or l a rge volu me s yr i nge) Fro m i ner t m ater i a l l i ke s ta i n le s s s te el , h igh den s ity p ol ye th Connection hoses - ylene (H D PE ) , P T F E ( p ol y te tra fluoro e thylene) or p ol yp ro p yl ene (PP) a re re com mende d for co n ne c tion s Us e o f p o l y vi nyl ch lor ide (P VC ) , s i l icon or p ol ye thylene ( PE ) s ho u ld b e avoide d Timing device to determine starting time of sampling or to measure duration of sampling Barometer to observe (several measuring) air pressure at sampling location Thermometer to measure ambient and soil gas temperature F lowme ter (ad ap te d to the flow n ge) D u s t fi lter (m ay b e ne ce s s a r y when fi ne mo bi le for VOCs sampling Described in Annex C f particles are expected in the monitoring well) - Made of inert materials that have no effect on the sampled compounds (e.g VOC and silica gel) P a r ticle s fi lter m ade o i ner t m ater i a l s H u m id ity fi lter (m ay b e ne ce s s a r y when s a m p l i ng i n ver y hu m id atmo s p here) © ISO 2017 – All rights reserved 45 ISO 18400-204:2017(E) Annex B (informative) Portable equipment to measure gases Table B.1 lists the portable instruments that are used to measure gases Table B.1 — Portable equipment to measure gases Instrument Infra-red spectrophotometer (IR) Gases analysed Carbon dioxide, (methane) aliphatic hydrocarbons Sensor with catalyt- ic oxidation Flammable gases Thermal conductivi- Carbon dioxide, ty detector (TCD) Flame ionization detector Laser flammable gases Flammable gases Most gases Electrochemical cells Oxygen Disadvantages Specific gases can be Reading may be a ffected by compounds analysed within pre-de - chemically similar (e.g ethane influence fined ranges methane measurement) Wide detection range Reading may be a ffected by moisture Sensing element may deteriorate with age Requires at least 15 % o f oxygen in the Sensitive measured gas Not methane-specific Not intrinsically sa fe Sample is destroyed as part o f measure - ment process Wide detection range Very sensitive Good for pinpointing emission sources Ammonia, oxygen, High precision hydrochloric or Very use ful for detectfluorhydric acid ing leaks Very easy to use Indicator tubes 46 Advantages Wide detection range Used for large number of gases Simple to use Not methane-specific Errors can occur at low concentrations Not methane-specific Not always intrinsically sa fe Requires oxygen Possible errors if high levels of carbon dioxide Sample is destroyed as part o f measure - ment process Device calibrated for a single gas Limited precision and readability High cross sensitivity Moisture can reduce sensitivity Limited shelf-life © ISO 2017 – All rights reserved ISO 18400-204:2017(E) Table B.1 (continued) Instrument Paramagnetic cell Photoionization detector (PID) Gases analysed Advantages Oxygen Volatile aromatic and aliphatic hydrocarbons Accuracy a ffected by changes in atmos - pheric pressure Detection of various Detection not specific ranges can be excluded No methane detection Different excitation Detector signal depends on connection energies possible Gas chromatograph (portable) (GC) equipped with Aromatic hydro appropriate detec- carbons, tors, e.g flame-ionElaborate ization detector volatile halogenat(FID), photoioniza- ed hydrocarbons tion detector (PID), heat conductivity detector (WLD) © ISO 2017 – All rights reserved Disadvantages Single component determination possible 47 ISO 18400-204:2017(E) Annex C (informative) E Table C.1 q u i p m e n t t o m e a s u r e f l o w r a t e s a n d b o r e h o l e p r e s s u r e l i s ts the i n s tr u ments that a re us e d to me a s ure flow rate s and b orehole pre s s u re T a b l e C Instrument — M E e q t u h o i p d m o f e n m t e t a o s u m r e e a m s e u n r e f l o w r a t e s a n d b o r e h o l e Advantages t p r e s s u r e Disadvantages M e a s u re d d i re c tl y T f l h o e r w m t r a a l d n s i s d p u e c r e s i o n r This instrument is now ed for the measurement f can also be used to measure gas pressure in the borehole (via calculation and calibration) This instrument is spef loss widel y u s e d a nd accep t o ga s flow T he mo n itor c i fic or low p re s s u re at monitoring point Simple method Robust, hand held f Flow measrate using thermal disper- monitor urement not affect- or contaminants f Presents negligible standpipe This can be a stand-alone instrument or in- impedance to the corporated into a hand-held gas monitor in some portable ground gas monitoring devices D i re c t me a s u rement o flow s ion flow tra n s ducer e d b y wi nd, s te am T h i s s en s or d i re c tl y me a s u re s the flow rate rom a ga s flow C o m mo n l y u s e d to me a s u re ga s flows Prone to dust and condensation build up T he flow tra n s ducer m ay b e calibrated for a certain gas composition If the gas measured is s ign i fic a ntl y d i fferent, cor re c tio n fac tors m ay ne e d to b e ap p l ie d Preheating time to take to account: ~30 (except for portable equipment) T he re s tric tio n i n the or i fice p l ate a r ti fic i a l l y re duce s ga s flow o Determines the pressure d ro p ac ro s s a n or i fice a nd O r i f i c e p l a t e c a lc u l ate s a flow bration curves from cali resulting in the under recording f f can also result in a high permanent pressure drop i.e outlet pressure will be about 60 % to 80 % of inlet pressure - — ga s flow rom the b oreho le I t O r i fice p l ate s a re pro ne to erosion, which in due course can generate inaccuracies in the measured differential pressure , Rotameters consist of a grad, uated vertical tube with a taper towards the lower end at monitoring point These instruments have Simple method f Flow measure- tube ment not affected priate for use on a gason the time taken for a soap bubble to rise up a graduated contaminants greater tube with a known volume Rotameters vane anemometers b u b b l e - f l o w m e t e r M e a s u re d d i re c tl y s F low i s rep re s ente d b y the b e en widel y u s e d p o s itio n o a flo at with i n the G enera l l y more ap pro B ub b le -flowme ters a re b a s e d s i n g l and fi l l s ite s where the pre s s u re a nd flow i s 48 b y wi nd , s te a m o r C a n on l y b e u s e d where ga s qu a ntity a nd pre s s u re a re h igh C a l ib ration i s a ffe c te d b y the sure of gas mixture Can underestimate Prone to damage Correction factors should be applied if the gas composition is ff f air den s ity, temp eratu re a nd pre s s ign i fic a ntl y d i erent to th at o © ISO 2017 – All rights reserved ISO 18400-204:2017(E) Table C.1 (continued) Instrument Soap bubble meters ff sistance and are therefore more appropriate for sites with low ever, the measurements can still be unreliable typ ic a l l y o er le s s re p re s s u re a nd flow H ow M e t h o d o f m e a s u r e m e n t The volume is recorded and converted to the volume Advantages Disadvantages flo w o f ga s Vane anemometers operate f revolutions per unit-time of a vane which rotates in the b y cou nti ng the nu mb er o pre s ence o f a ga s flow due to fluc tu ation s These instruments use a ed wire as a sensor As the Excellent spatial electrical resistance of most resolution metals is dependent upon the f temperature, a relationship can be obtained between the response resistance of the wire and ver y fi ne ele c tr ic a l l y-he at Hot wire anemometer H igh the ga s flow s p e e d © ISO 2017 – All rights reserved re quenc y Fragi le , c a n b e u s e d on l y i n cle a n ga s flows N e e d to b e re c a l i b rate d fre quently - due to du s t acc u mu l atio n (u n le s s the flow i s ver y cle a n) G enera l l y no t p u r p o s e - de s igne d Might be less sensitive than other methods and less reliable under practical conditions 49 ISO 18400-204:2017(E) Annex D (informative) E x a m p l e o f s a m p l i n g s h e e t Sample Name Project name: Date: Time: Sampler: Location: P r e - s i t e c h e c k s Equipment check – power supply, pumps, dis plays, filters Servicing up-to-date Calibration check (note any dri ft) Instrument type Instrument serial number Weather conditions (dry, rain) Outdoor temperature (°C) Indoor temperature (°C) Atmospheric pressure (Pa) (falling or rising) Air humidity (%) Wind speed and direction Sampling line description Sampling conditions Site conditions (e.g frozen, covered with snow, water logged, concrete) On-site activities (e.g construction or other works in progress) Off-site activities Sample description Identified pre ferential pathway Depth of response zone (m) Leakage test results Visual and/or ol factory observations Presence of water in the monitoring well On site measurements PID CO2 O2 H2S CH (ppm) 50 CO Pressure Soil gas tem- Soil gas water difference perature humidity table (Pa) (°C) (%) depth (m) © ISO 2017 – All rights reserved ISO 18400-204:2017(E) Nature and size (or mass) of sampling medium Type o f sup port Flow rate control - TO T1 (beginning) (midpoint) Time Flow rate l/min Temps Flow rate l/min O P h o t o g t r h a e p r h o y b s o f e r s v a a m t i p o l i n n T2 (end) Sample volume s g p o i n t Global view of the sampling point environment Global view of the sampling line Focus view on the sampling line Other photography © ISO 2017 – All rights reserved 51 ISO 18400-204:2017(E) Bibliography [1] ISO 18400-100, [2] ISO 18400-101, Soil quality — Sampling — Part 101: Framework for the preparation and application of a sampling plan standards Soil quality — Sampling — Part 100: Guidance on the selection of sampling [3] ISO 18400-102, [4] [5] [6] ISO 18400-103, Soil quality — Sampling — Part 103: Safety ISO 18400-1042) , Soil quality — Sampling — Part 104: Strategies ISO 18400-105, Soil quality — Sampling — Part 105: Packaging, transport, storage and preservation [7] [8] [9] [10] techniques Soil quality — Sampling — Part 102: Selection and application of sampling of samples ISO 18400-106, Soil quality — Sampling — Part 106: Quality control and quality assurance ISO 18400-201, Soil quality — Sampling — Part 201: Physical pretreatment in the field ISO 18400-202 2) , Soil quality — Sampling — Part 202: Preliminary investigations ISO 18400-203 2) , Soil quality — Sampling — Part 203: Investigation of potentially contaminated sites [11] ISO 18400-2052) , Soil quality — Sampling — Part 205: Guidance on the procedure for investigation of natural, near-natural and cultivates sites [12] ISO 18400-2062) , Soil quality — Sampling — Part 206: Guidance on the collection, handling and storage of soil for the assessment of biological functional and structural endpoints in the laboratory 2) Under preparation 52 © ISO 2017 – All rights reserved ISO 18400-204:2017(E) ICS 13.080.05 Price based on 52 pages © ISO 2017 – All rights reserved