Report /2008

Transcription

1 Report /2008 J. Bakker J.P.A. Lijzen H.J. van Wijnen Site-peciic human rik aement o oil contamination with volatile compound

2 RIVM Rapport /2008 Site-peciic human rik aement o oil contamination with volatile compound J. Bakker J.P.A. Lijzen H.J. van Wijnen Contact: J. Bakker RIVM-Stoen Expertie Centrum joot.bakker@rivm.nl hi invetigation ha been perormed by account o the Minitry o Spatial Planning, Houing and the Environment, Directorate General or the Environment, Directorate o Sutainable Production (DGM-DP), within the ramework o project , Rik in relation to Soil Quality RIVM, P.O. Box 1, 3720 BA Bilthoven, tel.: ; ax.: ,

3 RIVM 2008 Delen uit deze publicatie mogen worden overgenomen op voorwaarde van bronvermelding: 'Rijkintituut voor Volkgezondheid en Milieu (RIVM), de titel van de publicatie en het jaar van uitgave'. 2 RIVM report

4 Het rapport in het kort Locatiepeciieke humane riicobeoordeling van bodemverontreiniging met vluchtige verbindingen Het RIVM heet het zogeheten VOLASOIL-model verbeterd. Het model chat voor woningen en andere gebouwen de binnenluchtconcentratie die onttaan al gevolg van bodemverontreiniging met vluchtige verbindingen. Deze verontreiniging van bodem en grondwater kan zich voordoen in de omgeving van bijvoorbeeld benzinetation en chemiche waerijen. Om de riico hiervan voor de men te kunnen bepalen, berekent het model op bai van de vervuilinggraad van het grondwater de concentratie vluchtige toen in de binnenlucht. Het aangepate model maakt een betere riicobeoordeling mogelijk, zodat de mate van poed om te aneren beter i te bepalen. De nieuwe verie i voor meer typen woningen bruikbaar, namelijk voor woningen zonder kruipruimte o woningen met een kelder. Eerder wa het alleen bruikbaar voor woningen met een kruipruimte. Al vergelijking zijn voor de toegevoegde woningtypen twee alternatieve berekeningmethoden opgenomen die internationaal worden toegepat. Het rapport onderbouwt bovendien de waarden voor de belangrijkte parameter van de modelconcepten. Onder andere zijn karakteritieke eigenchappen van ze tandaard bodemtypen vereenvoudigd en verduidelijkt, waardoor lokale beoordelingen beter zijn uit te voeren. Daarnaat i aangeven wat de belangrijkte locatiepeciieke gegeven zijn van het model. Het i de bedoeling de modelconcepten van de nieuwe VOLASOIL-verie te gebruiken bij het beleidintrument voor bodemanering (SANSCRI), de uitwerking van het in 2008 herziene Saneringcriterium bodemanering. Op bai van de reultaten van de modelberekeningen kan beloten worden aanvullende (binnen)luchtmetingen te doen. De combinatie van modelleren en meten geet de bete bai om de riico van vluchtige verbindingen voor de men te beoordelen. rewoorden: VOLASOIL, bodemverontreiniging, binnenlucht, vervluchtiging RIVM report

5 Abtract Site-peciic human rik aement o oil contamination with volatile compound RIVM ha improved the VOLASOIL model. he model etimate the indoor air concentration o houe and other building originating rom oil contamination with volatile compound. hi contamination occur or example in the vicinity o petrol tation and dry cleaning. o etimate the rik or human, the model calculate the air concentration baed on the concentration in oil and or groundwater. he extended and updated model acilitate a better rik aement in the proce o determination o the urgency or remediation. In the pat, the model only wa uitable or building with a crawlpace. he current verion i extended or lab-on-grade building and building with a baement. For comparion with the tandard modelling approach concept alo two alternative model concept are included, which have been applied in other international model. hee alternative calculation model hould only be ued by expert uer. Furthermore the background and underpinning o the mot relevant parameter ha been evaluated and ha led to an adjutment o the value that can be elected in a ite peciic rik aement. Alo the mot important ite peciic parameter are given in the report. he cenario and model concept in VOLASOIL can be applied in the Remediation Criteria (SANSCRI), being revied in Baed on the reult o thee model calculation it can be decided whether unacceptable rik can be excluded. I not, it can be decided to do additional (indoor) air meaurement. he combination o modelling and air meaurement give the bet bai or deciion about human health rik and about the urgency or remediation. Key word: VOLASOIL, oil contamination, indoor air pollution, vapour intruion 4 RIVM report

6 Preace hi reearch at the National Intitute or Public Health and the Environment (RIVM) ha been carried out by commiion o the Minitry o Houing, Spatial Planning and the Environment (VROM), Directorate General or the Environment, Directorate o Sutainable Production (DGM-DP). he ubject o the rik aement o volatile compound, including the modelling, ha been extenively dicued with an external adviory group compoed o a number o expert rom everal intitute, conultancie and competent authoritie. Member o thi group were: A. Mayer (Mayer Milieuadvie), J. uintra (Royal Hakoning, now CB), J. Schreuder (DHV), J. Provoot (VIO, B), J. ter Meer (NO) and M. Waitz (Ingenieurbureau Amterdam). We are alo very grateul or the inormation, advice and remark provided by the expert group on humantoxicological rik aement (S. Boekhold (CB), C.J.M. van de Bogaard (VROM-Inpectie), D.H.J. van de Weerdt (HGM Arnhem),. Fat (Fatadvie), C. Hegger (GGD Rotterdam), J.E. Groenenberg (Alterra), J. Wezenbeek (Grontmij), J. uintra (CB), R.M.C. heelen (Miniterie van LNV), S. Dogger (Gezondheidraad), h. Vermeire (RIVM) and J. Lijzen (RIVM). Currently the new VOLASOIL model i programmed in excel, combined with the human expoure model CSOIL. It i planned to develop an external verion that can be approached or downloaded rom the internet. Both thi report and model code have been produced with care, however, thee product cannot be claimed to be ree o error. Ue o the reult obtained by mean o thee material i or the ull reponibility o the uer. Ue o the model i encouraged and eedback i welcomed. However, other than by mean o thi report, no technical upport i being oered. RIVM report

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8 Content Samenvatting 10 Summary Introduction Background Validation tudy External recommendation and evaluation Reader guide Framework or ite-peciic human rik aement General ramework Meaurement o (indoor) air concentration Modelling o expoure to indoor air Introduction Building and contamination cenario Building cenario Contamination cenario Input parameter Expoure cenario and expoure aement Other (international) model concept or indoor air modelling Ground bearing lab, model concept and aumption Houe with baement, crack at wall-loor interace, model concept and aumption Houe with crawl pace General dicuion on model concept Model concept or dierent type o building Introduction Building with crawlpace ranport rom oil/groundwater to the crawlpace Calculation o indoor air concentration, cenario crawlpace Slab-on-grade building Contruction type Combined diuive and convective tranport or two layer, the oil-loor ytem Calculation o the diuive lux through the oil-loor column Calculation o the convective air lux through the oil-loor column Calculation o indoor air concentration, cenario lab-on-grade 50 RIVM report

9 4.4 Building with baement General aumption Contaminant tranport into the cellar, baic calculation Calculation o indoor air concentration, cenario lab-on-grade Contaminant cenario Groundwater contamination; well-mixed container Contaminated groundwater in crawl pace or baement Floating oil-contaminant layer in the open capillary zone Groundwater in crawl pace or baement and a loating oil-contaminant layer Pure contaminant in open capillary zone Very low groundwater table Sinking oil-contaminant layer Contaminant ource beneath the groundwater table Etimating the vapour concentration o mixture Etimating ource depletion Selection o input parameter General Phyicochemical and toxicological data Site peciic data Other ite peciic data Soil type Air permeability oil Height capillary tranition boundary Quality o the loor Permeability and poroity o the loor and other building element Perimeter eam gap and crack ratio Ventilation characteritic, living room Ventilation characteritic crawl pace Generic input parameter Air preure dierence Dimenion o the building, crawl pace and cellar Floor and wall thickne Overview parameter and deault value Uncertainty and enitivity analyi Introduction Method Scenario analyi Generic approach Reult Senitivity analyi Uncertainty analyi Concluion Concluion and recommendation 93 8 RIVM report

10 Reerence 95 Appendix 1 Derivation o combined diuive and convective tranport through two layer, intact concrete loor 101 Appendix 2 Derivation o combined diuive and convective tranport through two layer, loor with crack and gap or a perimeter eam gap 105 Appendix 3 Combined diuive and convective tranport or contaminant ource beneath the groundwater table 109 Appendix 4 Overview o chronic limit value (CA) 112 Appendix 5 emperature correction o the vapour preure and olubility 115 Appendix 6 Additional ubtance propertie 117 Appendix 7 Example calculation or lab-on-grade and baement building cenario Slab-on-grade, intact loor Slab-on-grade, perimeter eam gap Slab-on-grade, loor with gap and hole Baement, intact loor and wall 124 Appendix 8 Dutch oil texture terminology 128 Appendix 9 Model input-parameter ditribution 129 Appendix 10 Reult o the Uncertainty analye or the VOLASOIL approach 133 Appendix 11 Reult o the Uncertainty analye or the Johnon and Ettinger approach 137 RIVM report

11 Samenvatting Voor het chatten van de mate van bodemverontreiniging en de mogelijke eecten hiervan op de men wordt gebruikgemaakt van het VOLASOIL-model. Het VOLASOIL-model berekent de concentratie in de binnenlucht van een woning die gebouwd i op een bodem die verontreinigd i met vluchtige verbindingen. Omdat het VOLASOIL-model alleen bruikbaar wa voor woningen met een kruipruimte en er naat dit type eveneen woningen zijn met een kelder o woningen zonder kruipruimte, wa er vanuit de praktijk van de riicobeoordeling de wen het model uit te breiden. Literatuuronderzoek wee uit dat er een aantal verchillende modellen i voor deze twee typen gebouwen en dat het tranport vanuit de bodem naar de binnenlucht van een woning op een aantal verchillende manieren kan worden berekend. Uit het oogpunt van conitentie i er voor gekozen om zoveel mogelijk bij het betaande model voor de woning met een kruipruimte aan te luiten. Voor de berekening van de concentratie in de binnenlucht voor de twee nieuwe modellen zijn eveneen twee alternatieve berekeningmethoden opgenomen. Deze alternatieve berekeningmethoden worden gebruikt in internationaal bekende alternatieve chattingmodellen. De alternatieve rekenmodellen zijn niet bedoeld voor de tandaard locatiepeciieke riicobeoordeling maar zijn bedoeld voor het uitvoeren van aanvullende beoordelingen door expert ter vergelijking met de tandaardmethode. Naat het optellen van modelconcepten voor de twee alternatieve woningtypen, i er uitgebreid literatuuronderzoek gedaan naar de waarde van de parameter die in de berekeningen worden gebruikt. Het gaat onder meer om de locatiepeciieke parameter, zoal poroiteit en luchtdoorlatendheid per bodemtype, de kwaliteit van de vloer en de ventilatiekarakteritieken, en de generieke parameter zoal drukverchillen in de bodem en tuen bodem en hui. Uit de verzamelde gegeven zijn de meet gangbare tandaardwaarden ageleid en i een aantal waarden aangepat. Ook i in het rapport aangeven hoe de verchillende waarden voor verchillende ituatie in de praktijk toe te paen. Het rapport bevat eveneen een gevoeligheid- en onzekerheidanalye. Met deze analye i geprobeerd inzicht te verkrijgen in het gedrag van de drie verchillende modellen. De analye geven daarnaat aan wat de belangrijkte parameter zijn van het model. Hierop kan men zich vervolgen richten om indien noodzakelijk een betere chatting te maken van de concentratie in de binnenlucht van woningen. Het i de bedoeling dat de modelconcepten voor de twee nieuwe woningtypen in VOLASOIL toegepat gaan worden in het nieuwe Saneringcriterium. Op bai van de reultaten van deze modelberekeningen kunnen luchtmetingen worden gedaan. Berekeningen en metingen amen geven de bete bai voor het bepalen van riico van vluchtige verontreinigingen. 10 RIVM report

12 Summary he human rik aement o oil contamination with volatile compound can be baed on modelling the indoor air concentration and meaurement o the air concentration. For the modelling o the indoor air concentration the VOLASOIL model can be ued. hi report preent the reult o the update o the model and decribe the principle o ite-peciic rik aement o oil contamination with volatile compound. Previouly, the VOLASOIL model could be ued only or building with a crawlpace (below the living loor). he new model i extended with a cenario or building with a baement (cellar) and a cenario or lab-on-grade building, becaue o the exitence o thee other type o dwelling and the expreed deire o model uer. he literature earch carried out howed that dierent model concept are available or thee additional building cenario and that the tranport rom the oil to the indoor air can be calculated in alternative way. For the additional building cenario one deault and two alternative model concept have been included. he alternative concept are being ued in internationally known expoure etimation model. Literature reearch wa carried out or the mot relevant model parameter. hi concern ite peciic parameter, like oil type dependent poroity and air permeability, the quality o the loor and ventilation characteritic, and general parameter like preure dierence in the oil and between oil and building. he value were evaluated and the bet value or ite peciic rik aement were elected, leading to an adjutment o the value that can be elected in ite peciic rik aement. It i alo indicated, which value can be ued in dierent ituation. A enitivity and uncertainty analyi wa carried out with each model concept applying common value range or the relevant parameter. he reult indicate how the model perorm in dierent ituation and how which parameter are the mot important depending on the circumtance. hi inormation i important when the model i ued to etimate the indoor air concentration and to carry out a rik aement or volatile compound originating rom oil contamination. he cenario and model concept or the two new building type in VOLASOIL can be applied in the Remediation criterion, which i being revied in Baed on the reult o thee model calculation it can be decided whether unacceptable rik can be excluded or not. I not, it can be decided to remediate or to do additional air meaurement. he combination o modelling and meaurement give the bet bae or deciion about human health rik. RIVM report

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14 1. Introduction 1.1 Background Rik aement o human expoure to volatile compound in oil and groundwater ha been part o the aement o oil contamination or a long time in the Netherland. It i included in de human expoure model CSOIL that i ued or deriving o the Intervention Value or oil and groundwater (Swartje, 1999; Lijzen et al., 2001). he current Intervention Value are given in a Miniterial Circular (VROM, 2000). he etimation o the expoure to volatile compound or generic rik aement i baed on a tandard reidential cenario with ixed building dimenion and oil condition. With thee etting, generic rik limit (Intervention Value) or oil and groundwater can be derived. For ite peciic rik aement it ha been made poible to adjut the mot relevant parameter to etimate the concentration in indoor air baed on the meaured concentration in oil and groundwater. Firt, or ite peciic rik aement in general the Remediation Urgency Method (RUM) wa developed (in Dutch: Saneringurgentie ytematiek : SUS (VROM, 1995)). he ite peciic rik aement in SUS help to determine the urgency or remediation and upport deciion about how to remediate contaminated ite. he SUS conit o three element: o human rik; o ecological rik; o rik due to contaminant migration. A ite with oil contamination i not conidered to be urgent when there i no actual rik or one o thee element. o upport the rik aement o volatile compound in particular the VOLASOIL model wa developed (Waitz et al., 1996). hi model gave more opportunitie to adjut to the local ituation and included alo a modiication o the model concept. he VOLASOIL model calculate the indoor air concentration or the Dutch ituation in building ituated on oil contaminated with volatile compound. he model i uitable or ite-peciic rik aement becaue o the poibility o a lexible combination o modelling and meaurement. It can be ued or everal peciic contamination cae, or intance loating contaminant layer, contaminant ource beneath the groundwater table, pure contaminant in the open capillary zone, contaminated groundwater in crawl pace, et cetera. he tarting point or the improvement i the current remediation urgency method (RUM), a decribed in VROM (1995), together with the concept in the VOLASOIL model and the reult o the evaluation o the intervention value. he goal o thi tudy wa to improve the ite peciic human rik aement o oil and groundwater contamination. Recently an extended political evaluation o the ramework or oil quality aement wa publihed (VROM, 2003a). hi reulted in a revied philoophy on oil protection. he main addition to the preent philoophy concern: o a impler and more conitent ramework; o more ocu on utainability; o a (urther) hit to itne or ue and regional reponibility. In 2006 a Miniterial Circular on oil remediation wa publihed (VROM, 2006) that replace the Remediation Urgency Method. In particular the policy ha changed wherea the rik aement methodology i till almot the ame. he ue o meaurement in contact media ha gained importance in the econd tep o the rik aement. In 2008 alo the Miniterial Circulair wa updated with the calculation o ite peciic rik, including inormation preented in thi report. hi Circular and the new oil policy include a (urther) hit to itne or ue. hi mean that ite-peciic rik aement will gain importance. he approach preented in thi report i part o a revied methodology on ite peciic human rik aement (Lijzen et al., in prep.). RIVM report

15 Baed on the analyi preented in Lijzen et al. (2003) objective were deined or urther improvement o the ite-peciic rik aement. Baed on interview with expert and earlier evaluation o the method, the main retraint are indicated and option or olution have been prioritied, partly baed on cientiic eaibility. It wa planned to ocu on eparate part o the methodology. Beide the general human rik aement, the emphai lay on the ollowing retraint related tot the human expoure to oil contamination with volatile compound: o uncertainty about the determination o the human rik or inhalation o indoor air; o lacking o the determination o the rik o volatile compound in building with a lab-on-grade loor; o o weighing o reult rom model calculation with meaurement; lacking o pragmatic guideline or additional meaurement (bioavailability, indoor air, conumption crop). he ollowing ubject were identiied to improve the rik aement and help to olve thee retraint: o evaluation o guideline or meaurement o contaminant in (indoor) air in relation to oil pollution and the relation between calculation and meaurement; o implementation o the reult o the project Evaluation o Intervention Value oil (Lijzen et al., 2001); o development o a model concept or the rik aement o volatile compound in building without a crawlpace (lab-on-grade); o integration o the expoure model VOLASOIL and CSOIL; o dicuion on how modelling and meaurement hould be integrated in a ramework (alo baed on the expected uncertaintie within both method). Exiting ield data o volatile compound in indoor air have been ued to carry out a validation tudy (Van Wijnen and Lijzen 2006; ee ection 1.2). For the tranport o volatile compound into building alo additional model development ha been carried out, which i preented in thi report. For perorming meaurement in (indoor) air, a guideline i written that give guidance on how to carry out meaurement and how to interpret in relation with calculation (Otte et al., 2007). 1.2 Validation tudy In 2004 and 2005 a validation tudy (Van Wijnen and Lijzen, 2006) wa carried out in order to compare rik aement baed on modelling with actual meaurement in oil air, crawlpace and baement air, and indoor air. In that report it wa concluded that the VOLASOIL model etimate the indoor air concentration or tetrachloroethylene and trichloroethylene reaonably well. he tudy how that the model overetimate at high groundwater concentration and underetimate at lower groundwater concentration. hi doe not have to be a problem when it i accepted that ome overetimation i unctional, becaue the etimation hould be protective or mot ituation. In a econd tep, meaurement can reduce the potential overetimation. o etablih a realitic air concentration (with a higher probability o underetimation) a reviion o the current model i needed. Some actor can be important in explaining the dierence between modelling and actual meaurement: e.g. degradation in the unaturated zone; limit in the tranport rom contaminant rom groundwater to the oil air; the type o building and the eaon in which meaurement are carried out. In the report the ollowing recommendation were given or adjutment o the modelling o indoor air concentration: o Adjutment o the relationhip between crawlpace air and indoor air i neceary in the way that the deault contribution o crawlpace air to indoor air i between 0.1 and 0.3 (current deault value o 0.1 i lower); o Adjutment o the tranport rom groundwater to crawlpace air. he tranport could be ytematically lowered, but when wort cae calculation are acceptable no adjutment hould be made; 14 RIVM report

16 o For rik aement only groundwater concentration under or within 10 meter o the building and concentration in the top layer o the groundwater hould be ued; o here hould be a guideline on how to deal with heterogeneity o the contamination and the time cale in which groundwater meaurement can be ued or rik aement; o More inormation hould be given on the ditribution o input-parameter in order to make an eaier election; o he oil air raction hould be oil type dependent; o A ma balance check hould be added to be able to check how long a calculated lux can exit; o It hould be poible to ue the depth o the unaturated zone intead o the depth o the groundwater table. hee recommendation are ued in the urther development o the exiting model. 1.3 External recommendation and evaluation In advie o the Soil echnical Committee (CB, 2002) and the Dutch Health Council (Health Council, 2004) about deriving Intervention value (generic Soil Quality criteria) it wa tated that modelling o air concentration implie a lot o uncertainty and that ite peciic meaurement hould be important in making deciion about remediation. Alo it wa tated that the model concept o volatiliation wa not validated. Part o the uncertainty can be reduced by uing ite-peciic inormation in the rik aement. Secondly the rik aement can be improved by carrying out meaurement in contact media or omewhere in the tranport route rom ource to receptor. Dicuing thee ubject bring u to the quetion to what extent modelling hould contribute to the rik aement o volatile compound. In principle modelling and meaurement hould not lead to complete dierent aement o rik and both hould upport each other in a methodology. Modelling give reult that can be reproduced, wherea meaurement in air are more relevant or the actual expoure, but can be (extremely) time dependant. For the ite peciic rik aement it wa thereore decided that ite peciic modelling hould be the tart o rik aement and that meaurement hould be ued in the next tep o a tiered procedure in the cae that the objective are exceeded. For more detail about thi procedure we reer to chapter Reader guide In chapter 2 a revied ramework or ite-peciic human-toxicological rik aement i preented and the relation with the Miniterial Circular on oil remediation criteria i given. Alo an outline o the poibilitie to carry out meaurement in air i given in chapter 2. Chapter 3 decribe the ituation and contamination cenario that hould be identiied when modelling the indoor air concentration. Chapter 4 decribe the model concept o indoor air modelling o volatile compound or dierent building type and contamination cenario. In chapter 5 the mot important model parameter are decribed and the advied deault etting and choice are given. In chapter 6 a enitivity and uncertainty analyi wa carried out. he concluion and recommendation are ummaried in chapter 7. RIVM report

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18 2. Framework or ite-peciic human rik aement 2.1 General ramework Until recently the method or the ite-peciic human rik aement wa put down in the Remediation Urgency Method (SUS) (VROM, 1995, 1998). hi method wa implemented in a computeried deciion upport ytem. hi computer otware wa developed by the Van Hall Intitute by order o the Minitry o VROM in he new Dutch oil policy ( Beleidbrie bodem : VROM, 2003a) include, amongt other, a (urther) hit to itne or ue. hi mean that the ite peciic rik aement will gain importance. In 2006 the Remediation Urgency Sytem i replaced by a new Remediation Criteria (in Dutch: Saneringcriterium) in the Miniterial Circular on oil remediation he Remediation Criteria i thereore the policy context o the ramework, being updated in 2008 (VROM, 2006, 2008). o improve the location peciic (or actual) rik aement everal activitie have been carried out. hi included the ramework o the human ite peciic rik aement. hi ramework and it element will be reported more extenively (Lijzen et al., in prep). It upport the approach a preented in the publihed Remediation Criteria (VROM, 2006, 2008). he ramework hould be uitable or dierent goal: o determination o the urgency or remediation o contaminated ite; o advie local authoritie about health rik or human; o deriving remediation objective and oil quality tandard. In Figure 2-1 the cheme o the ramework i given. he dierent tep in the ramework are hortly decribed with a ocu on the aement o volatile compound. Within the ramework a tiered approach i choen, comparable with the approach that i currently ued in the remediation urgency method. A indicated, the reult o the aement hould primarily be ued in etting the environmental priority or remediation, but can alo be ued or etting tandard or land ue peciic oil quality. Figure 2-1 preent the three tier o the ramework and the preelection. Preelection In the preelection phae it hould be made clear which meaured concentration hould be ued or the rik aement. When thee concentration are higher than a certain level (Intervention Value) tier 1 hould be tarted. Other peciic circumtance could alo be decribed in which rik aement i neceary, beide concentration level. For example when volatile compound are ound in groundwater and the groundwater level i very hallow. Furthermore the goal o the rik aement ha to be et in thi tier, becaue thi inluence the elected toxicological criteria. For volatile compound e.g. the goal can be to know i the indoor air i inluenced by contamination in oil and groundwater. In that cae not only the olerable Concentration in Air (CA) i ued or the aement. ier 1 For tier 1 it i propoed to make clear -with a concentration lit- below which concentration in oil and groundwater no human rik are expected (below the Maximum olerable Rik level, MR, or human). hereore the relevant expoure pathway are determined (ingetion o and dermal contact with oil and dut, crop conumption, inhalation o indoor air, permeation o drinking water main and ih conumption). In act wort cae ituation are being calculated. For volatile compound it i recommended to go to tier 2 directly, becaue location peciic inormation can be ued or the aement (depth o groundwater table, type o oil RIVM report

19 and type o building). In cae that a loating layer or pure product i preent in unaturated oil, you hould go to tier 2 and tier 3. In the circumtance that it i already decided to remediate, ometime additional human rik aement i not carried out. In thee cae it can be concluded, baed on thi inormation, whether a potential rik or human i preent or not. ier 2 In tier 2 a more extenive rik aement i carried out, baed on peciic tandard cenario, meaured concentration and ite-peciic data. Only tandard ite-peciic data that can eaily be meaured are ued. hi tier can be ued in the tandard rik aement o the Remediation Criteria (VROM, 2006). When the Maximal Permiible Rik (or Negligible rik) i exceeded baed on thi aement, a tier 3 rik aement hould be carried out ór the rik hould be accepted and meaure/remediation hould be carried out to reduce the rik or human. hi report ocue on the model concept that can be implemented or expoure aement in thi tier. ier 3 In tier 3 more ite peciic inormation can be ued. Epecially meaurement in contact media can carried out, but alo other meaurement to improve the rik aement can be done. In particular the ollowing media could be meaured: o concentration in air (indoor air, crawlpace air, and baement, oil air and/or outdoor air); o concentration in plant (or meaurement o bioavailability in oil related to the plant content); o bioacceibility o contaminant in oil/dut within the gatro-intetinal track (in particular or lead and arenic); o concentration in drinking water; o concentration in ih. For the ampling o thee media a uniorm guideline or protocol i neceary. Guideline or the irt three type o meaurement are publihed in Otte et al. (2007), Swartje et al. (2007) and Oomen et al. (2006). In thee guideline it hould be made clear when and how meaurement can be carried out and how the reult o the additional reearch hould be interpreted compared to the calculation. hee guideline will have a poition in Remediation Criteria method and have been tuned with important takeholder. A ummary o the guideline or indoor air meaurement i given in ection 2.2. Deciion o local authority he general ramework end with a deciion or action (tier 4). In the context o the Remediation Criteria ( Saneringcriterium ) it i tated that unacceptable rik hould be eliminated a oon a poible (temporary meaure to reduce expoure) and that, in principle, remediation hould tart within 4 year ater the deciion o the authority. 18 RIVM report

20 Start Meaurement in oil and groundwater rom upected ite 0a. Coil> IW-oil and/or Cgroundwater> IW-groundwater or high crop conumption or depth o contaminant <1,25 m -mv or potential pure product? Ye No OK pre-election 0b Determine goal o aement: remediation objective oil or location pec. rik aement ree choice o going to tier 1 or directly to tier 2 Volatile compound preent? -> go to tier 2! Ye Ye potential rik accepted No 1a Direct contact, crop growing, permeation o drinking water pipe and/or indoor expoure poible? objective: potential rik preent 1b C oil and C groundwater > critical concentration or wort cae human expoure cenario? 2a Select relevant expoure cenario (actual or uture) and relevant toxicological value (include background expoure?) No OK ier 1 imple aement Ye Ye Rik accepted 2b Give relevant concentration, and available ite peciic data 2c I total (modelled) expoure rom contaminated oil, groundwater and/or ediment > oral MR or > (%o) inhalative MR (CA)? Ye Rik No OK ier 2 cenario (tandard) rik aement No 3a Do additional location-peciic meaurement: in contact media air, oil/dut (bioacceability), crop or drinking water (and ediment/urace water or ih) Rik Ye 3b Meaurement > critical concentration? or i (total) expoure rom oil, groundwater or ediment > oral MR or >inhalative MR (CA)? No ier 3 detailed (ite peciic) rik aement (additional Meaurement) 3c Doe interpretation o ite peciic calculation and meaurement (e.g. mean o both) lead to location-peciic rik? No OK No Rik accepted Ye Unacceptable Rik Ye 4. Action Remediation hould be perormed and/or (temporary) meaure hould be taken Deciion on remediation Figure 2-1 Framework or the ite-peciic human rik aement RIVM report

21 2.2 Meaurement o (indoor) air concentration he model calculation that are decribed in the ollowing chapter o the report give the opportunity to etimate the (indoor) air concentration baed on the ite peciic circumtance. When, baed on thee calculation the critical air concentration (motly the olerable Concentration in Air, CA) i exceeded, air meaurement hould be carried out. hi i part o tier 3 in the procedure or ite-peciic human rik aement preented in Figure 2-2. In Otte et al. (2007) guidance i given on how to carry out thee meaurement. hi ection give an outline o thi guidance in order to give inight in the tep that can ollow ater the model etimation. Alo more in depth inormation i provided about how to et up a trategy or meaurement, the technique to ue and how to obtain additional data. It i not meant to be rigid, but a an aid or thoe who carry out meaurement or who have to decide about oil remediation. For more inoramtionabout meaurement we reer to Otte et al. (2007). Step 1. he irt tep i the determination o the trigger or tarting meaurement. hi trigger hould be clear and upported by all takeholder. A trigger can be e.g. complaint o reident, odour threhold or exceeding the CA in model calculation. Step 2. Secondly, the quetion that hould be anwered mut be clear. Every takeholder ha it own quetion and interet. Baed on thee quetion a clear criterion hould be ormulated that can be teted with the meaurement (where and how long thi type o criteria hould be met). Step 3. hird, the value o the criterion hould be choen. A lit o the odour threhold and chronic Maximal Permiible Rik or air (CA) i available in the guidance. Step 4. Additional inormation hould be gathered to be able to make a good interpretation o the reult o the meaurement. he additional inormation give inormation in order to ae the ource, path and the degree o expoure. Step 5. he ormulation o the meaurement plan i the central tep in the guidance. With thi plan the expoure level, link to the oil contamination and excluion o internal ource hould be provided. In principle it i advied to have two ampling period. Step 6. In tep 6 the meaurement technique hould be choen. hi include e.g. the choice o active or paive ampling and the duration o the ampling. It hould be time averaged ampling. Step 7. he lat tep conit o data analyi, interpretation, concluion and the deciion. he abolute level a well a the conitency o the data can be checked to draw concluion on to what extend air concentration are inluenced by oil contamination. he reult o the model calculation hould alo be ued or the interpretation. 20 RIVM report

22 Step Example o tandard ituation rigger or additional meaurement Ye Step 1 Complaint o reident Modelling air concentration indicate indoor air concentration > CA (olerable Concentration in air) Phrae quetion and goal Step 2 Caue the oil contamination unacceptable health rik? Determination o teting criteria Step 3 CA odor threhold Decribe local ituation Collect additional inormation Formulate meaurement plan Select meaurement technique Step 4 Step 5 Step 6 Point o pecial interet: analye expoure route, layout o the building, poible internal and external ource, type o contamination, oil type, heterogeneity, ventilation by reident, ventilation, weather and climate, type o building Standard meaurement plan, e.g. : 2 period and each period: Minimal 2 meaurement in living area, 2 meaurement in crawlpace/baement, 2 meaurement outide 4 meaurement in oil air Selected meaurement technique: paive ampler (VOC), Soil air with lot point method Analye and interpret data Concluion and deciion Step 7 Example: Average concentration indoor > CL concentration outide << C inide concentration crawlpace > C inide concentration oil air ~ C crawlpace Concluion: rik unacceptable and due to oil contamination Figure 2-2: General approach o the rik aement o volatile compound in oil baed on air meaurement RIVM report

23 22 RIVM report

24 3. Modelling o expoure to indoor air 3.1 Introduction When volatile compound are preent in oil or groundwater above Intervention Value it i recommended to carry out calculation to etimate the indoor air concentration baed on ite peciic characteritic. It hould alo be noticed that below the (human) Intervention Value rik could occur in cae the groundwater i very hallow or the contamination i within the irt meter o the oil. hi recommendation mean that wort cae calculation, a uggeted or tier 1 o the ramework, are not recommended or volatile compound. In thi chapter the general etup o the modelling i decribed. Beore calculation can be done, the appropriate cenario hould be choen that it the type o building and type o contamination (ee ection 3.2). Some general apect o the input parameter are mentioned in ection 3.3. In ection 3.4 the relation with the expoure cenario i decribed. An exploration o the internationally available model concept i preented in ection Building and contamination cenario Building cenario hi ection give an overview o the three building cenario and it baic aumption. he model concept decribing the tranport rom the oil contaminant into the indoor pace are given in ection 4.2 to 4.4. More detail and background o the mot relevant parameter i given in chapter Building with crawl pace For a building with a crawl pace, the tranport into the indoor pace conit o two tep, ee Figure 3-1. Firt the contaminant i tranported rom the contaminant ource through the unaturated oil layer into the crawl pace. he econd tep i the tranport rom the crawl pace through the building loor into the indoor living pace. he typical building parameter and their value are given below. Area and volume: he loor area o the building i aumed to be 50 m 2 (5 m x 10 m). he volume o the living pace i 150 m 3. he depth o the crawl pace beneath the oil urace i 0.4 m and the volume o the crawl pace i 25 m 3 (the height o the crawlpace i 0.5 m) (Waitz et al., 1996). Ventilation rate: he baic ventilation rate o the crawl pace i 0.8 h -1, the ventilation o the indoor air depend on the degree o the ventilation (air tightne o a building) and (deault) value can be choen a een it or the ite peciic ituation. Preure dierence: he preure dierence between the oil and the crawl pace i et at 1 Pa and the preure dierence between the crawl pace and the living room i alo 1 Pa (Rikken et al., 2001; ee alo ection o thi report). Floor: he deault thickne o the (concrete) loor i aumed to be 10 cm. RIVM report

25 Figure 3-1 Houe with crawl pace Building with lab-on-grade A building with the ground level loor on oil ha no crawl pace and thereore the contaminant i tranported directly rom the oil through the loor into the indoor living pace, ee Figure 3-2. ypical building characteritic are the ame a or the building with a crawl pace. Area and volume: he loor area o the building i the ame a in the crawl pace cenario (50 m 2 ). he volume o the living pace i 150 m 3. Preure dierence: he preure dierence between the building and the underlying oil i aumed to be the ame a the air preure dierence or the living pace o the building with crawl pace, ΔP 1 Pa. (ee ection 5.5.1). Floor: he thickne o the loor i et at a deault value o 10 cm. 24 RIVM report

26 Figure 3-2 Houe with ground bearing lab (lab-on-grade) Building with baement he ituation or a building with a baement i comparable to that o a building with a lab-on-grade loor. he contaminant i the tranport directly into the building rom the contaminant ource through the oil and the baement loor. Additionally there i tranport through the baement wall into the tructure, ee Figure 3-3. It i aumed that the baement i ituated under the whole building. Alo the indoor pace o the building i modelled a one compartment. A treed beore, both contaminant tranport through the loor and the wall o the baement i taken into account. Area and volume: he oot print area o the cellar i equal to the loor area o the building, which i 50 m 2 (5m * 10m). he height o the cellar i 2 m (under the ground urace). he total cellar wall area i thereore 60 m 2. Conequently the volume o the baement i 100 m 3. Ventilation rate: he building i aumed to be a well-mixed container, including the cellar (ee or intance Johnon and Ettinger, 1991). hi aume direct and complete mixing o the cellar air with the air in the living pace. Preure dierence: he preure dierence between the building and the underlying oil i aumed to be the ame a the air preure dierence between the living pace and the crawl pace o the building with crawl pace (ΔP 1 Pa). he ame applie or the lab-on-grade model, ΔP 1 Pa. (ee alo ection 5.5.1) Wall and loor: he thickne o the baement wall i uually in the range o cm. A 10 cm thickne or concrete looring i adequate or reidential baement, ee alo chapter 5. he baement can either be build rom concrete lab (precat panel), concrete block or brick or rom poured concrete. Poured concrete i more reitant to water and ha ewer and maller void than concrete block. Baement wall made with block unit and concrete panel uually have many joint where the (maonry) unit connect to each. hee oundation type have great potential or developing crack. RIVM report

27 Figure 3-3 Houe with a baement Contamination cenario hi ection deal with the poible combination o a building type and the peciic contamination cae, which decribe combination o the location and the phyical appearance o the contaminant in the oil (able 3-1). A detailed decription o thee cae i given in ection 4.5 and in Waitz et al. (1996). Scenario o the oil contamination: A Groundwater contamination (well-mixed container) B Groundwater in crawl pace/baement/living room C Floating oil-contaminant layer D Groundwater in crawl pace/baement/living room and a loating oil-contaminant layer E Pure contaminant in open capillary zone (ee additional meaurement) F Very low groundwater table G Sinking oil-contaminant layer H Contaminant ource beneath groundwater table (ee additional meaurement) In very peciic cae (ee cenario B and D in able 3-1) it i advied to perorm meaurement becaue either the available model are not appropriate or the peciic cae might lead to high expoure. Furthermore it i aumed that the combination o a building with a ground bearing lab and cenario B and D i not valid a thi ituation would not appear in practie. Alo in the ituation where a baement i ued a a living pace a combination with cenario B and D i thought not to be relevant. hee peciic ituation are not likely becaue either thi type o reidence are not build in ituation with high groundwater level or pecial proviion have been taken to prevent leakage o groundwater in the occupied baement or living pace. 26 RIVM report

28 able 3-1 Valid combination o contamination cenario and building type Scenario Crawl pace Slab-on-grade Baement A Groundwater contamination (well-mixed x x x container) B Groundwater in crawl pace/baement x# - (x)# C Floating oil-contaminant layer x x x D Groundwater in crawl pace/baement and a x# - (x)# loating oil-contaminant layer E Pure contaminant in open capillary zone x x x F** Very low groundwater table x x x G* Sinking oil-contaminant layer x x x H Contaminant ource beneath groundwater table x x x x valid combination o a building type and peciic contamination cae (x) can in principle occur, but expected to be unlikely - invalid combination # meaurement in baement or crawlpace neceary * ame a A: groundwater concentration ued a input ** oil air concentration or bulk oil concentration in a region near the tructure hould be ued a input 3.3 Input parameter For the modelling o (indoor) air concentration many parameter are neceary. Part o thee parameter can be et a deault parameter that hould not be changed becaue they are part o the elected cenario. he model parameter are decribed in more detail in chapter 5 in more detail. Beide thee deault parameter, the ollowing type o parameter can be ditinguihed: o compound-peciic parameter. Value or ome o thee parameter, like phyical-chemical propertie and toxicological parameter are included in thi report (Appendix 4 and 6). It i decribed which kind o compound peciic parameter are neceary or the calculation (ee ection 5.2); o generic parameter. Some parameter are time dependant (eaonally). he model decription i not time depend and thi type o parameter hould in principle not be changed. Still when (ite) peciic data would become available, the value could be changed to the new value. Example o thi type o parameter are the preure dierence (Δ P), temperature, and the baic ventilation rate o the crawlpace (ee ection 5.5); o ite peciic parameter. Eential parameter are the concentration in groundwater or oil and the depth o the groundwater table or contamination. Alo a meaured oil air concentration could be ued. On the other hand there are many parameter that make it poible to adjut the calculation baed on ite peciic inormation. Several preet value can be choen. In thi way alo the enitivity o the model or certain parameter can be ound. Example o thee parameter are the quality o the loor and the indoor air ventilation rate (ee ection 5.3 and 5.4). A ummary o the input parameter i given in ection Expoure cenario and expoure aement It i planned to include the model concept a implemented in VOLASOIL in the CSOIL-model, together with the model concept o the new building cenario. hi can lead to the ituation that there i one model in the Netherland or the calculation o expoure to volatile compound rom oil contamination. he land ue cenario in CSOIL are combined with the building and contaminant cenario and can be ued or the rik aement. RIVM report

29 It i recommended to dierentiate between two expoure cenario. he irt i reidential land ue, in which the expoure time i during the whole day (24 h). he CA ha not to be corrected. Secondly there i the land ue with building in which people only tay during the working day (at the mot 8 hour per day, 5 day a week). he calculated relevant air concentration i thereore corrected with a actor 40/168. Only or compound or which the acute toxicity i equal to the chronic toxicity (e.g. cyanide, ee Lijzen et al., in prep), thi hould not be done. When the aement o volatile compound i integrated in the expoure aement o other expoure route, the combined expoure to volatile compound via indoor air and other expoure route hould be aeed. o take the other route into account the um o the expoure index to air and the expoure index to other expoure route ha a maximal value o Other (international) model concept or indoor air modelling Ground bearing lab, model concept and aumption General decription he model decribed by Ferguon et al. (1995) and Krylov and Ferguon (1998), which are alo applied in the CLEA-model (EA, 2002) conider diuion through variou looring material and convective tranport through crack and gap a eparate procee. hu, neglecting the diuion through gap where convection procee prevail and neglecting the low o oil air through porou material where diuion prevail, ee Figure 3-4. Cia Floor urace Soil urace Capillary tranition boundry J d J J d+j c J c Ca z z0 z Figure 3-4 ranport luxe rom oil into a building with ground bearing lab a modelled by Ferguon et al. (1995) Diuion he looring material i conidered a a porou material with a peciic eective molecular diuibility o the contaminant in the relevant material o a peciied thickne. Common material ued in a typical loor contruction comprie a hard-core bae with and blinding, over which a concrete layer, an inulation layer, a PVC damp-proo heet and a decking material (wooden loor, carpet etc.) i placed. he actual diuibility o 28 RIVM report

30 thi contruction i calculated rom the component diuion coeicient. Ferguon et al. (1995) demontrate that the total eective diuion coeicient o the looring layer i determined mainly by the concrete layer due to it thickne and relatively low poroity. he diuive lux i calculated uing Fick irt law o diuion Jd dc ( Cia Ca) D D e (Equation 3.1) dx L Jd diuive lux o contaminant [g.m -2.h -1 ] D e total eective diuion coeicient [m 2.h -1 ] Cia concentration inide the houe [g.m -3 ] Ca concentration in oil air [g.m -3 ] L total thickne o the loor layer [m] D e n i 0 i L L / D e i (Equation 3.2) D e total eective diuion coeicient [m 2.h -1 ] L total thickne o all ditinctive loor layer together [m] L i thickne o ditinctive loor layer [m] D i e eective diuion coeicient o each ditinctive layer [m 2.h -1 ] n number o loor layer [-] Convection Convective tranport (Jc) reult rom the preure dierence between the oil-ga and the air inide a houe. he preure gradient i aumed to caue a contaminant lux by convective low o oil air, to the indoor air via pore pace, gap and crack. he characteritic path length i determined by the depth o the oundation, loor thickne and the location o gap and crack. A characteritic path length (length o oil column, L) o 1 m i ued a a deault value. he path length i not aumed to be dependent on the groundwater level in thi model. It i urthermore aumed that the loor or ubloor barrier i o permeable, relative to oil, that preure driven convective low through crack and gap will be limited almot entirely by the oil zone. hi mean that the calculation o the generated air lux i olely baed on the oil air permeability. ranport by diuion through oil i not modelled. A uniorm ource with ga phae concentration (Ca), direct beneath the loor i aumed. he convective low i calculated according to Darcy Law: κ ΔPi Jc V. Ca Ca (Equation 3.3) η L RIVM report