Comparison of risk assessment methods for polluted soils in Sweden, Norway and Denmark

Transcription

1 Department of Physical Geography and Quaternary Geology Comparison of risk assessment methods for polluted soils in Sweden, Norway and Denmark Viktor Plevrakis Master s thesis Physical Geography and Quaternary Geology, 30 Credits NKA

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3 Preface This Master s thesis is Viktor Plevrakis' degree project in Physical Geography and Quaternary Geology at the Department of Physical Geography and Quaternary Geology, Stockholm University. The Master s thesis comprises 30 credits (one term of full-time studies). Supervisor has been Jerker Jarsjö at the Department of Physical Geography and Quaternary Geology, Stockholm University. Extern supervisor has been Johanna Moreskog, URS Nordic. Examiner has been Andrew Frampton at the Department of Physical Geography and Quaternary Geology, Stockholm University. The author is responsible for the contents of this thesis. Stockholm, 19 November 2014 Lars-Ove Westerberg Director of studies

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5 Abstract Land contamination is an acknowledged problem around the world due to its potentially adverse impacts on human health and the environment. Specifically in Europe there are estimated to be 2,500,000 potentially contaminated sites. The risk that contaminated sites pose is investigated by risk assessments. The methods and the models though used in risk assessments, vary both on a national and an international level. In this study, the risk assessment methods and models for polluted soils used in Scandinavia and issued by the Environmental Protection Agencies were compared. The comparison aimed to (i) identify similarities and differences in the risk assessment methodology and risk assessment methods and to (ii) investigate to which extend these differences can impact the results of the models and the implications regarding mitigation measures. The method and model comparison showed that Sweden and Norway have great similarities in assessing risks for contaminated soil. However, there are differences with Denmark on a conceptual level. When a common hypothetical petrol station with 20 soil samples was assessed, the results and the conclusions of the three risk assessments were quite different; the site was seen as posing risk to human health with the Danish model when complied with the quality criteria issued by the Norwegian model. The Swedish risk assessment concluded that the contaminant concentration in 3 out of 20 samples was potentially harmful for the environment but not for human health. The demonstrated divergence of the conclusions of risk assessments has major implications and shows great interest for mainly four groups: Land-owners who may be called to cover the expenses for remedial action. Consultants and companies who perform risk assessments and land remediation. The countries that have to meet national and international environmental goals and can also share/ or cover the cost for remedial action. The people exposed to such environments that could be deemed as potentially harmful by a neighboring country. The study was conducted in collaboration with URS Nordic. i

6 Acknowledgments First of all, I would like to express my gratitude to my two supervisors Jerker Jarsjö and Johanna Moreskog for the supervision and guidance throughout my thesis. Jerker has provided me great support at all different levels of our collaboration and helped me overcome the various difficulties that came up during the thesis. Johanna opened the door for me to URS Nordic by suggesting the research topic and contributed with her deep understanding and knowledge on risk assessments. Big thanks goes also to URS Nordic for allocating time and resources to train me, transfer knowledge and providing me an office to work in the beginning of my thesis. Ken Jenkins has been the first person that I met from URS Nordic and who understood the benefits of a potential collaboration of Stockholm University and URS. I am grateful that he facilitated to start this project. I would like to thank all the employees of URS Nordic for the fruitful discussions around risk assessments in Scandinavia but especially Åsa Lindström, Nicklas Gingborn and Sophie Andersson who helped me with specific parts of the models. Furthermore, I want to thank Sanne Arildsen who has offered substantial help to topics around the Danish risk assessment methodology. The support of Aidin Geranmayeh when I was trying to put all the pieces together is likewise highly appreciated. Our vigorous discussions helped me to clarify critical aspects of risk assessments. Finally, I would like to thank my family who has supported me over this two-year period of my studies and encouraged me to take the next step in my education. ii

7 Table of Contents List of Abbreviations... iv 1. Introduction Aims of the study Background information to Risk Assessments Swedish and Norwegian Risk Assessments Danish Risk Assessment Methods Case study Site description CSM and model parameterization Influence of each exposure pathway conservation goal on site Analysis of the exposure path of consumption of groundwater Results Method and model comparison Case study Compliance of the field concentrations with the quality criteria and recognition of most influential paths Analysis of the exposure path of consumption of groundwater Discussion Method and model comparison Case study Importance of the results Potential sources of errors and limitations of the results Conclusions References Appendix iii

8 List of Abbreviations CES Classes of Environmental State CSM Conceptual Site Model EPA Environmental Protection Agency IGV Individual Guideline Value GGV Generic Guideline Value KM Känslig Markanvändning, Sensitive land use in the Swedish model MKM Mindre Känslig Markanvändning, Less sensitive land use in the Swedish model SSGV Site Specific Guideline Value TDI Tolerable Daily Intake TPH Total Petroleum Hydrocarbons TRV Toxicity Reference Value WFD Water Framework Directive iv

9 1. Introduction Land contamination is an acknowledged problem around the world that has to be managed in an efficient way in order to decrease the threat for human health and the environment. Contaminated land can have major economic and legal implications especially in the light of the pollutant pays principle introduced in 2012 by the Waste Framework Directive within the European Union (European Commission 2012). A contaminated site is defined as a site where the concentration of pollutants exceeds the background concentration (Naturvårdsverket 2009b). Only in Europe there are over than 340,000 identified contaminated sites and the number is constantly increasing as, many sites remain to be identified. Currently, 2,500,000 sites are estimated to be potentially contaminated in Europe (European Commission 2014). Among the Scandinavian countries, there are 80,000 sites suspected to be contaminated in Sweden (Naturvårdsverket 2012), 4,500 in Norway (Miljødirektoratet 2014) and there are already 29,000 sites identified as contaminated in Denmark (Miljøstyrelsen 2014a). Assessing the risk that contaminated sites entail is complex (e.g. Guyonnet et al. 2003; Labieniec et al. 1997; Paustenbach 2000; Thompson et al. 1992). In order to assess this risk, and prioritize action, a risk analysis followed by a risk assessment take place according to the legislation in the Nordic countries (e.g. Miljøstyrelsen 2011, 2013; Miljøverndepartementet 2009; Naturvårdsverket 2006, 2009a 2009b). A risk analysis is a process where the probability of an undesirable event to happen and the consequences it has, are identified and quantified. Risk assessment is the 1

10 comparison of the results of risk analysis with acceptable criteria or values (Miljøstyrelsen 2002). The outcome of the risk assessment has often a great effect on the requirements for remedial action (Cushman et al. 2001; Ferguson et al. 1998; Guyonnet et al. 2003; Li et al. 2007). The risk assessment methods can vary from qualitative to quantitative (Linkov et al. 2009), in the degree of complexity (e.g. Peters et al. 1999; Suter 2006), in the models that are used while investigating a site (Van Straalen 2002) and finally in the results and the conclusions they produce (Miljøstyrelsen 2012). On a national level, the local Environmental Protection Agency (EPA) is responsible to publish guidelines and/or a model that give directions of how such assessments should be carried out in order to offer a common starting point for discussions and more consistency in the risk assessment procedure (Miljøstyrelsen 2002; Naturvårdsverket 2002). On a European level it is known that there are substantial differences in the underlying site definitions and interpretations of such assessments (European Commission 2014). More and more effort is put into identifying these differences by transferring knowledge between the involved parties and establishing common ground for analysis and discussion (e.g. Ferguson et al. 1998). The work of Network for Industrially Contaminated Land in Europe (NICOLE) that compares legislation, risk analysis and risk assessment methods across Europe is an example of such an attempt from the land-owners side (NICOLE 2004). In Academia, Troldborg (2010) has compared risk assessment methods for groundwater contamination. From the EPA s side there are a few examples of such comparisons among the methods (e.g. ecological risk assessment methods between Netherlands, Norway, Sweden and UK by Miljøstyrelsen, 2012). So far, to the best of my knowledge, there has been no 2

11 comparison in the risk assessment methods and models between the Scandinavian countries Aims of the study The main aims of the study are to (i) identify similarities and differences in the risk assessment methodology and the risk assessment models for contaminated land in Scandinavia, and (ii) investigate to which extend these differences can impact the results of the models and the implications regarding mitigation measures. Addressing aim (ii), the methods are applied to a common investigation site. The compared countries are Sweden, Norway and Denmark and the models have been issued by the respective EPAs (Naturvårdsverket, Miljødirektoratet, Miljøstyrelsen). 2. Background information to Risk Assessments A risk assessment for a contaminated site is an iterative process with several phases that gradually build up in complexity. In this section basic background information for risk assessments is provided based on the study of the manuals issued by the EPAs. The information describes the most important characteristics of a risk assessment and how do the risk assessment models fit in the picture. As the manuals of the EPAs are totaling more than a thousand pages this study summarized and reproduced only a small fragment of them without any ambition to replace them. The information mainly includes the workflow in a risk assessment study, the different phases it has, and its most important characteristics in regards to the case study that was examined. The information is first provided for the Swedish and the Norwegian model and then for the Danish one. The order of presentation was chosen to have 3

12 better flow in the text since the Norwegian risk assessment model was constructed based on the Swedish one and they share common features (Naturvårdsverket 2006). The first step in a risk assessment is the construction of a Conceptual Site Model (CSM). Based on the available information, the contaminant sources, the migration pathways that may apply, the exposure paths to the receptors and finally the receptors that are exposed are identified. This step is desktop conducted and gives a qualitative approach to the type of the risk that may exist (Naturvårdsverket 2009a & 2009b; Miljøverndepartementet 1999 & 2009; Miljøstyrelsen 2002 & 2012). If the outcome of the qualitative risk assessment is that there is a potential risk for humans and/or the environment the paths of the three models start deviating from each other Swedish and Norwegian Risk Assessments Guidelines The next step in Swedish and Norwegian risk assessments is a basic (screening level) risk assessment. A basic or simplified risk assessment is the first quantitative assessment of the contaminated site during which the measured concentrations of contaminants in soil (mg/kg) or the concentrations expected to be found there, are compared with generic guidelines values (GGVs). The GGVs are thresholds of values of compounds in the field, below which no adverse effects for the recipients are expected to occur. They do not though constitute legally binding values. GGVs refer to normal/typical conditions and are not tailor-made for the site. Moreover, GGVs are related to protected recipients and the exposure paths through which they may be reached (Naturvårdsverket 2009b). 4

13 Land use In Sweden there is a lower and a higher guideline value given for chemical compounds for sensitive land-use (Känslig Markanvändning-KM) and less sensitive land-use (Mindre Känslig Markanvändning-MKM) respectively. Simply put, this binary categorization refers to two scenarios for land-use where different activities take place involving different exposure time and concomitantly resulting to a different exposure to danger. In Norway the measured concentrations of the contaminants in the field fall into five Classes of Environmental State (CES) and are labeled from very good (CES one) to very bad (CES five). Depending on the future land use (residential area, offices, industrial area) and the contamination depth (above or below one meter) different CES can be accepted for the site (Miljøstyrelsen 2012; Miljøverndepartementet 2009). If the on-site concentrations comply with the GGVs the investigation is finished and the expected risk for the recipients is acceptable. If the field concentrations are over the guidelines, a comprehensive risk assessment should be considered. During this phase, site specific guidelines values (SSGVs) are generated based on a greater level on the investigated site s characteristics. This is conducted by the use of the software supplied by the EPAs. Depending on site characteristics the same concentration of contaminants may pose a different risk Risk Assessments Input Variables The site description in the Swedish and the Norwegian models is done with the use of approximately 40 variables. The most important of them are common between the 5

14 models and describe among others the geometry of the contaminated area and the buildings, the lithology and the aquifer s characteristics Starting point for calculations in the models With the site specific input values the chemical processes that take place between a hot spot and the recipient included in the risk assessment models are calculated. Fate and contaminant transport include diffusion, dispersion, sorption but this is done in an inverse way in the Swedish and the Norwegian models; having as a starting point the accepted quality criteria in the vicinity of the receptor (e.g. toxicological references for humans in air or groundwater) the contaminant concentration in the source is calculated. Since some variables may have higher uncertainty in their values or may be totally unknown this step of the analysis can be performed additional times to show how the uncertainty impacts the results (Miljøstyrelsen 2012). The chemical compounds are treated individually during the calculations meaning that no interrelation between the substances takes place. The measured soil concentrations of contaminants are not used in these calculations but they can be inserted to give the expected concentration in the other media (pore water, groundwater, air in soil voids etc.) Recipients and exposure paths A risk assessment is always linked to the recipients/ conservation objectives that are exposed. The Swedish model identifies human health, environment, groundwater and surface water as conservation objectives. Human health is exposed through seven pathways: soil intake, skin contact, inhalation of soil particles, inhalation of vapors, consumption of groundwater (private well), consumption of vegetables 6

15 cultivated on-site and consumption of fish that come from a lake downstream from the site. In an MKM study the pathways of consumption of groundwater, vegetables and fish are opted out as considered unrealistic. The exposure pathway of consumption of fish is calculated by the model but does not affect the final guideline value due to the high level of uncertainty in the results. The uncertainty stems from the long and complex transport pathway from the point source to a nearby surface water body and the difficulty to relate adverse health effects with consumption of fish leaving in the water body (Naturvårdsverket 2009b). It should be commented that the guideline referring to groundwater concerns among other things the use of groundwater for irrigation, industrial use, how groundwater contaminants spread to water recipients downstream as lakes and wetlands, the risk of inhalation of vapors outside of the contaminated site etc. It should not be confused with the risk of consumption of groundwater which focuses only on the health impact of drinking groundwater (Naturvårdsverket 2009b). In the Norwegian risk assessment model, human health is the only identified receptor. The exposure pathways are the same as in the Swedish model and the software can be parameterized to disregard certain of them Weighing of the recipients generation of final value The final SSGV takes into consideration the guidelines from the individual contaminant pathways and conservation goals. This is done in a different way depending on the structure of the model. 7

16 Fig. 1. Simplified schematic representation of how the final SSGV is generated in the Swedish model. The Individual Guidelines Values from each exposure path and protection goal on the left of the figure are grouped together in intermediate bigger groups and finally give birth to the SSGV on the right. In the Swedish model the final guideline is calculated through three intermediate guidelines as presented in Fig. 1. The first intermediate guideline corresponds to human health risk and is based on the six exposure pathways. Among the six pathways only that with the lowest value applies as it is the only one that fulfills the quality criteria for the rest of the group. (The Individual Guideline Values (IGVs) C is, C du, C id, C iv, C iw and C ig are called envägskoncentration in the Swedish model). The lowest IGV is further reduced to 50%, 20%, or 10% of the initial value and is called afterwards health-based guideline value. The percentage of reduction depends on the nature of the substance and is applied taking into consideration the exposure of the recipients by other pollutant sources that are currently not explicitly examined in the risk assessment and may therefore be unknown. Thus only a fragment of the total daily intake (TDI) should be reached. The health-based guideline value is screened with the guideline value for environment and the guideline value for 8

17 spreading of contaminants. The lowest of those three values becomes the final SSGV and is manually compared with the on-site concentrations (Naturvårdsverket 2009b). In the Norwegian model only the health based guideline value C he is quantified and issued by the software. C he is based on all six exposure pathways in Fig. 1 plus the risk of consumption of fish and is given by the formula: C he = 1 1 Cis + 1 C + 1 du C + 1 id C + 1 iv C + 1 iw C + 1 ig C if (1) where C is is the IGV for soil ingestion, C du for skin contact, C id for inhalation of soil particles, C iv for inhalation of vapors, C iw for consumption of groundwater, C ig for consumption of vegetables and C if for consumption of fish. This means in practice that C he is equal to or smaller than the smallest individual guideline value. Finally, the concentrations in the field are manually compared by the user or inserted into the software for a comparison (Miljøverndepartementet 1999) Danish Risk Assessment After the construction of the CSM, a Danish risk assessment approaches the exposure pathways of soil ingestion, skin contact and consumption of vegetables and fish with GGVs values for soil. The Danish model JAGG 2.0 assesses the risk related to human exposure through inhalation of dust indoors and outdoors and consumption of groundwater complimenting the GGVs. JAGG is a conservative model designed to assess the risk for the most sensitive receptor regardless of land use. That means that all exposure pathways are assessed despite the CSM. Due to the structure of the model, fulfillment of the quality criteria for a certain pathway does not automatically mean that the site satisfies the criteria for the other pathways as well. Thus all the pathways are investigated individually (Miljøstyrelsen 2012). 9

18 The input variables are similar to the Swedish and the Norwegian models although the interface is quite different. The model is consisted of different tabs/ sub-models corresponding to exposure pathways and work independently to each other. Each sub-model gives a result for only the specific pathway. The starting point in the Danish model is to parameterize it to the case study and set in the measured contaminant concentrations from the field. The expected concentrations in the final media close to the recipients are calculated with the model and are compared with inbuilt quality criteria for air and groundwater (Miljøstyrelsen 2013). The final result is if the site complies with the criteria or not. Hence the Danish model does not generate any SSGVs. Regarding the treatment of the chemical compounds in the model, there are two big groups of substances. Oil related substances that treat the substances as a cocktail mixture, and single substances where the contaminants are processed individually as if no other pollutants exist on site. In the oil related substances the interrelation of the substances concentrations results to an increased difficulty for the user to understand how the calculations are run for a specific contaminant. During contaminant transport from the source to the recipient, concentrations of new oil related compounds (meaning, not used as input) are calculated. For example, based on the concentration of TPH C6-C35, benzene and toluene, the concentration of naphthalene, fluoranthene and aromatic hydrocarbons is calculated through the model. 10

19 3. Methods The selection of the countries to compare the risk assessment methodologies was based on the availability of informative material, the experience of the employees in URS Nordic who contributed to the study and the field of interests of the company. The first step of the study was to make a comparison in the structure of the risk assessment methods and models based on the information provided in the Background information to Risk Assessments section. The comparison is made to reveal conceptual differences in risk assessments and models across the countries. The second step was to approach a common contaminated site with the three methodologies in order to investigate how the expected conceptual differences are reflected in the results of a risk assessment. The case study refers to a contaminated petrol station since petrol stations are frequently occurring subjects of risk assessment studies in all three countries. In particular, the module of consumption of groundwater was further compared among the models. The comparison aimed to give an insight of how do the models run the calculations for a common protection goal Case study Site description The case study area is hypothetical and was created and provided by URS Nordic based on typical data from actual investigations in Scandinavia. The case study concerns a petrol station active since 2003, with a surface of 1900 m 2 that is asphalted (Appendix Figure 1). On the SW side there are three buildings next to each 11

20 other with a total surface of 200 m 2. They serve as car wash, workshop and convenience store. The petrol station is located 100 m away from a registered drinking water well. No schools or kindergartens are situated within a 500 m radius from it. The lithology under the station is described by the cores of ten boreholes and is consisted of fill material for the first 3 m, sand 3-5 m and gravel between 5-7 m. No data exist for depths greater than 7 m. The layers are homogeneous and do not differentiate laterally. The groundwater level is at 3 m below the surface and the hydraulic gradient is m/m towards southeast. Lab analysis results that describe the concentration of contaminants in soil (mg of contaminants per kg dry weight of soil) are available at two different depths for each borehole, resulting to 20 samples (Appendix Table 1). The following petroleum related chemical compounds were measured: Aliphatic hydrocarbons C5-C35 Aromatic hydrocarbons C5-C35 Benzene Toluene Ethylbenzene Xylenes (m-, o- and p-xylenes) and Methyl tert-butyl Ether (MtBE). 12

21 CSM and model parameterization Initially a CSM was constructed based on the available information and is presented in Fig. 2. The exposure pathways of consumption of groundwater, vegetables and fish were not taken into consideration and are shown with yellow. No well is situated on site, the petrol station does not constitute cultivated land and there is no lake or other water body hosting fish as a recipient in the vicinity of the site. The processes that are applicable are highlighted with green. Fig. 2. Conceptual Site Model (CSM) for the case study describing the contaminant transport from the source to the recipients. The natural flow is from left to right and includes the primary and the secondary contaminant sources, the spreading mechanisms, the contact media, the exposure pathways and finally the recipients on the far right side. Green boxes stand for applicable processes on our site and are connected with black lines/ arrows while yellow boxes are interrelated with grey lines/ arrows and do not apply to the case study. The current CSM is based on a template from URS Nordic. To have common ground for comparison, the models were parameterized as far as possible with the same values. Unique or non-universal variables among the models were set with reasonable for the site values according to site characteristics. The basic configuration of the models is given in Appendix (Tables 2, 3 and 4). 13

22 Through the investigation of the site with the Swedish model the site was viewed as MKM and the exposure pathways that were excluded in the CSM did not apply. During the simplified risk assessment the GGVs of MKM were used and addressed the concentration of aliphatic and aromatic hydrocarbons, benzene, toluene, xylenes and MtBE. Due to fractionation in the hydrocarbons this resulted to guidelines for 13 substances. In the Norwegian model there was not an option in the software to exclude all the non- applicable exposure pathways shown in the CSM and this was done by setting zero values to certain parameters (e.g. 0% of water or vegetable consumption comes from the studied site). According to the average contamination depth (1.1 m) and the land use of the site that is industrial, the contaminants concentrations had to be in CES 1-4 to be accepted in a simplified risk assessment. The chemical compounds that were used in this classification were aliphatic hydrocarbons, benzene, toluene, ethylbenzene, xylenes and MtBE. Again, the aliphatic hydrocarbons were fractionated leading to SSGVs for 10 substances. In the Danish model all the exposure pathways were assessed including the consumption of groundwater that was disregarded by the other models. This was done since it is the typical risk assessment procedure in Denmark even if it may seem inconsistent with the followed procedure in the other two countries. The measured soil concentrations for the 20 samples were set in the model one at a time and the calculated concentrations in indoor/ outdoor air and groundwater were compared with the quality criteria. Total petroleum hydrocarbons C6-C35, benzene, toluene, ethylbenzene and xylenes were set in the oil related substances and treated 14

23 as cocktail mixtures while MtBE were chosen from the simple substances list and treated individually Influence of each exposure pathway conservation goal on site The most important exposure pathways in the case study were identified through two different procedures: First the pathways/conservation goals that had the largest effect on each SSGV in the Swedish and the Norwegian model were identified. Since there are guidelines values for 13 and 10 substances respectively, the influence of each pathway can be gauged by the number of substances it mostly affects. In the Swedish model the dominating exposure pathway/ conservation goal accompanies the final result as given by the software. In the Norwegian model it was found manually by identifying the lowest guideline value among the exposure pathways for each substance. According to Eqn (1) the lowest guideline value has the biggest effect on the final SSGV. Secondly, see for which exposure pathways the measured concentrations in soil samples lead to calculated concentrations in the other media higher than the quality criteria. From this perspective an exposure pathway that poses a risk in a higher number of boreholes/ samples than another is more important. This approach was followed with the Danish model based on the fact that the model does not issue SSGVs and the previous procedure could not be applied. 15

24 Analysis of the exposure path of consumption of groundwater After gauging the influence of each exposure pathway only consumption of groundwater was further examined considering the time limitations and the complexity of such an analysis. The certain exposure pathway was selected because it was present in all models and appealed more to my personal interests than the other common exposure path (inhalation of vapors). To compare the models results for consumption of groundwater, the Swedish and the Norwegian model were parameterized to include the additional exposure paths. The three models had only three common chemical compounds on-site that could be used as a comparison for the calculations: benzene, toluene and MtBE. The specified concentration for these three compounds is the same in 18/20 samples (see Appendix). SB03/1 was one of them and was selected as a representative sample to be set as input. 4. Results The result section includes a comparison of the methods and the models in the three countries and the results of the models in the case study. In the case study it is first presented if the specified concentrations in soil samples are accepted by each model. Then the most important exposure pathways/ conservation goals are identified and finally a comparison of the module for consumption of groundwater among the models takes place. 16

25 4.1. Method and model comparison Table 1 presents a summary of the main differences and similarities in the methodology and the models across the countries. The information derives from the Background Information section but is given more clearly in a form of a comparison in the table below. The Swedish and the Norwegian model have similarities in the workflow of a risk assessment, on the type of results they give, on the treatment of the substances and on the differentiations on land-use criteria during the simplified risk assessment. Table 1. Comparison of how Sweden, Norway and Denmark approach five common fields in the course of a risk assessment of contaminated land. Nr Compared field Swedish Norwegian Danish 1 Existence and role of land use in the methodology KM and MKM Residential area, offices, industrial area Only the most sensitive land use criteria apply 2 Input variables Similar variables across the models for the same branches. Fractionation is different. 3 Treatment of chemical compounds in the model Substances are treated individually/ no correlation among the contaminants Substances are treated individually/ no correlation among the contaminants 4 Type of results the model produces 5 Workflow in the model Certain substances are treated as a cocktail mixture and others individually SSGVs for soil SSGVs for soil Contaminant concentration in the air and groundwater Starting from the accepted contaminant concentration close to the recipient, SSGVs for soil contamination are calculated by the model Starting from the accepted contaminant concentration close to the recipient, SSGVs for soil contamination are calculated by the model Starting from the measured contaminant concentration in the soil, the model calculates the expected concentration of contaminants in the air and groundwater Table 2 contains information about the models in the three compared countries. It includes the conservation goals and the exposure paths that are assessed in each case, the parts of the model that affect the final result (marked with dashed rectangles) and the model parts that apply in our case study. In the Norwegian model the risk for the 17

26 environment is qualitatively approached but not addressed by the software. If such a risk exists, national, general environmental ambitions by the EPA or local requirements should be met and therefore explicitly investigated (Miljøverndepartementet 1999). Table 2. Recipients and exposure paths identified in all the models. The tick sign means that such a value can be generated by the model while x that it cannot. Green cells represent the active parts of the model in our case study and grey the inactive. The orange rectangles with the dashed outline are the parts of the software that contribute to the final results. In the Swedish model there are three rectangles instead of one to show an intermediate calculating step that is absent in the other models. In the Norwegian and in the Danish model all cells are equally weighed. Protection goals Exposure paths Swedish Norwegian Danish Human Soil ingestion x Skin contact x Inhalation of soil x particles Inhalation of vapors (indoors) (outdoors) Consumption of groundwater Consumption of x vegetables Consumption of x fish Environment x x Groundwater x x Surface water x x Free phase x 4.2. Case study Compliance of the field concentrations with the quality criteria and recognition of most influential paths The field concentrations exceeded the GGVs in both the Swedish and the Norwegian model at boreholes SB03, SB05 and SB10. The following advanced risk assessment generated SSGVs presented in Table 3. For each compound the most influential pathway/ conservation goal accompanies the SSGV and is shown in the same table. Despite the different fractionation it is clear that the Swedish model has much lower SSGVs than the Norwegian model. The Swedish guidelines range from five times 18

27 lower than the Norwegian in the case of aliphatic hydrocarbons >C8-C10 to up to ten thousand times more in MtBE. Table 3. GGVs and SSGVs for the studied petrol station in Sweden and Norway for different chemical compounds. The concentrations are given in mg of contaminants per kg of soil. Sweden Substance SSGV Most influential pathway/ conservation goal SSGV Aliphatic hydrocarbons C5-C6 18 Groundwater 406 Aliphatic hydrocarbons >C6-C8 120 Groundwater 1,498 Aliphatic hydrocarbons >C8-C Inhalation of vapors Aliphatic hydrocarbons >C10-C Environment 2,881 Norway Most influential pathway/ conservation goal Inhalation of vapors Inhalation of vapors Inhalation of vapors Inhalation of vapors Aliphatic hydrocarbons >C12-C Environment - - Aliphatic hydrocarbons >C16-C35 1,000 Environment - - Aliphatic hydrocarbons >C12-C >20,000 Soil ingestion Aromatic hydrocarbons C8-C10 50 Environment - - Aromatic hydrocarbons >C10-C16 15 Environment - - Benzene Groundwater 0.66 Toluene 15 Groundwater 245 Ethylbenzenes 15 Groundwater 906 Xylenes 20 Groundwater 812 MtBE 0.25 Groundwater 2,588 Concerning the most important exposure pathways/ conservation goals in the case study, the guideline for protection of groundwater has the greatest impact on more than half of the substances (7/13) in the Swedish model. Protection of environment comes next by controlling five out of thirteen substances and inhalation of vapors only one. In the Norwegian model the dominating exposure pathways is the inhalation of vapors controlling nine out of ten chemical compounds. Soil ingestion is the most influential pathway in only one substance. The two models coincide in the identification of the most influential pathway only in aliphatic hydrocarbons 530 Inhalation of vapors Inhalation of vapors Inhalation of vapors Inhalation of vapors Inhalation of vapors 19

28 >C8-C10 (inhalation of vapors) and have the minimum difference in the issued guideline. In Table 4a the SSGV of the Swedish model are compared with the on-site concentrations. The four samples coming from boreholes SB03, SB05 (both depths) and SB10 have concentrations of the analyzed parameters in collected soil samples below the SSGV. The compounds that exceed the values are marked with red and are: aliphatic hydrocarbons C5-C6: one sample with double concentration than SSGV, aliphatic hydrocarbons >C8-C10: one sample with 11% higher concentration than SSGV, aliphatic hydrocarbons >C10-C12: one sample with approximately 10% concentration over SSGV, aliphatic hydrocarbons >C12-C16: one sample with higher than double concentration than the SSGV, aliphatic hydrocarbons >C16-C35: one sample exceeding the SSGV by 57%, aromatic hydrocarbons >C10-C16: three samples exceeding the SSGV by 3, 9 and 5 times and benzene: one sample having approximately 7 times higher concentration than the SSGV. In the Norwegian model all analyzed parameters from the collected samples reported below the SSGVs. Table 4b shows which soil samples (marked with orange) required further investigation after the simplified risk assessment but were later on accepted as the risk for human health was acceptable. 20

29 Table 4. (a) Comparison of the concentration of 13 substances (left side) in 20 different samples with the SSGV generated by the Swedish model. Red cells indicate that the samples are over both GGVs and SSGVs while the non-highlighted cells mean that they comply with them. (b) Comparison of the concentration of 10 substances with the GGVs in the Norwegian model. Orange cells are within the fifth CES while the rest concentrations are in lower CES requiring no advanced risk assessment. All the concentrations comply with the SSGVs in the Norwegian model. Sweden Samples Substances SB01/1 SB01/2 SB03/1 SB03/2 SB04/1 SB04/2 SB05/1 SB05/2 SB06/1 SB06/2 SB07/1 SB07/2 SB08/1 SB08/2 SB10/1 SB10/2 SB11/1 SB11/2 SB12/1 SB12/2 Aliphatic hydrocarbons C5-C Aliphatic hydrocarbons >C6-C Aliphatic hydrocarbons >C8-C Aliphatic hydrocarbons >C10-C Aliphatic hydrocarbons >C12-C Aliphatic hydrocarbons >C16-C Aromatic hydrocarbons C8-C Aromatic hydrocarbons >C10-C Benzene Toluene Ethylbenzenes Xylenes MtBE Norway Samples Substances SB01/1 SB01/2 SB03/1 SB03/2 SB04/1 SB04/2 SB05/1 SB05/2 SB06/1 SB06/2 SB07/1 SB07/2 SB08/1 SB08/2 SB10/1 SB10/2 SB11/1 SB11/2 SB12/1 SB12/2 Aliphatic hydrocarbons C5-C Aliphatic hydrocarbons >C6-C Aliphatic hydrocarbons >C8-C Aliphatic hydrocarbons >C10-C Aliphatic hydrocarbons >C12-C Benzene Toluene Ethylbenzenes Xylenes MtBE

30 In the Danish risk assessment all the samples complied with the GGVs for soil. The calculated compounds concentrations in indoors and outdoors air complied with the air quality criteria in all boreholes. On the contrary, the estimated groundwater concentration of the compounds was higher than the drinking norms in every sample. In Table 5 the results from the groundwater module are presented for three randomly selected samples: SB03/1, SB05/1 and SB05/2. The TPH concentration in groundwater is at least 59 times over the limit across the three boreholes, reaching the highest value in SB05/1. SB05/2 has the highest concentration in aromatic hydrocarbons which exceed the groundwater criteria by 200 times and has the highest concentration in toluene. The calculated concentration of MtBE and naphthalene is over the drinking norms for the three samples. Benzene and fluoranthene concentration is within the standards whereas toluene exceeds them only in SB05/2. Table 5. Results of the Danish model for groundwater. The substances presented on the left side are split into two groups depending on if their soil concentrations are input to the model (first four compounds) or if they are calculated by the software. The three columns on the right show the ratio of the calculated groundwater concentration of the substances to the groundwater quality criteria based on the hypothetical observation data from soil samples SB03/1, SB05/1, SB05/2. Danish model - Groundwater Ratio of calculated groundwater concentration to groundwater criteria Substance SB03/1 SB05/1 SB05/2 TPH C6 - C Benzene Toluene MtBE Naphthalene Fluoranthene Aromatic hydrocarbons C9 -C

31 Analysis of the exposure path of consumption of groundwater Table 6 presents the calculated pore water and groundwater concentrations based on the hypothetical observation data from soil sample SB03/1 for benzene, toluene and MtBE. Quality criteria for groundwater are also presented in the last line for each compound and they are related to drinking norms. For the Swedish and the Danish model, the quality criteria have the form of maximum contaminant level (mg/l). The Norwegian model uses TDI criteria (mg/kg of body weight per day) and therefore could not be compared with the other two models. For the Swedish and the Danish model the groundwater concentrations are highlighted with either green or red depending on if the exceed the maximum contaminant level. Table 6. Comparison of calculated pore water concentration and groundwater concentration, groundwater criteria and SSGVs in benzene, toluene and MTBE across the models. The calculations are based on the hypothetical observation data from soil sample SB03/1. The concentrations in soil and in groundwater highlighted with green, fulfill the quality criteria or the guidelines while the red ones do not. Benzene Swedish Norwegian Danish Specified concentration in soil (mg/kg) IGV for groundwater (mg/kg) Calculated pore water concentration (mg/l) Calculated groundwater concentration (mg/l) Groundwater criteria (mg/l) Toluene Swedish Norwegian Danish Specified concentration in soil (mg/kg) IGV for groundwater (mg/kg) Calculated pore water concentration (mg/l) Calculated groundwater concentration (mg/l) Groundwater criteria (mg/l) MtBE Swedish Norwegian Danish Specified concentration in soil (mg/kg) IGV for groundwater (mg/kg) Calculated pore water concentration (mg/l) Calculated groundwater concentration (mg/l) Groundwater criteria (mg/l)

32 Additionally, Table 6 shows the IGV for groundwater in the Swedish and the Norwegian model. When the IGV is higher than the field concentration the sample complies with the guidelines and the concentration is highlighted with green (first line). For the Danish model there are no IGVs and the color of highlight depends only on the groundwater concentration. For all three substances the soil concentrations are below the SSGVs issued by the Swedish and the Norwegian model. In the Danish model, benzene and toluene concentrations are accepted but MtBE has six time higher concentration than the drinking norms (marked with red). In the case of the Swedish model it is clear that a compliance with the IGV does not mean that the water quality criteria/ drinking norms are met; for benzene the calculated groundwater concentration is over the maximum contaminant level but the soil concentration is still within the guidelines. For toluene and MtBE both soil and groundwater concentrations comply with the guidelines and the criteria respectively. A comparison of the groundwater criteria between the Swedish and the Danish model shows similar criteria for benzene but considerable differences in toluene and MtBE. Toluene has 70 times higher acceptable concentration in the Swedish model than in the Danish model while for MtBE it is 7 times higher. When it comes to pore- and groundwater concentrations given by the models all three of them have similar values for MtBE. On the contrary the Danish model gives quite smaller concentrations for benzene and toluene than the other two models. 24

33 5. Discussion The discussion follows the structure of the result section and is consisted of four parts. First the results of the method and the model comparison are analyzed and then the case study is on the focus. A discussion of the importance of the results and their implications on a broader level follows with a brief report to the limitations of the study Method and model comparison The Swedish and the Norwegian risk assessment methods for contaminated land show great similarities. Both countries have a common backbone when they assess the risk for contaminated land, described by a two-phase risk assessment, use of GGVs, consideration of land-use, similar fate and transport analysis of the contaminants and a final generation of SSGVs. These similarities expand to the models that are used for risk assessment and involve comparable equations, interfaces and standards (Miljøverndepartementet 1999) in the calculations. Overall it can be said that the two countries have very close methods and models to assess the risk deriving from contaminated areas. This was an expected conclusion since the Norwegian model is based on an old version of the Swedish one (Naturvårdsverket 2006). The Danish risk assessment methodology is more difficult to be compared with the Swedish and the Norwegian ones for the following reasons. 25

34 The type of the results given by the models (SSGVs and final concentration in the vicinity of the recipient) are not comparable. The inverse calculation path that is followed by the Swedish and Norwegian model compared to the Danish one. The cocktail mixture approach in the Danish model that takes into consideration the interaction between the contaminants while the other models assume only interaction of the contaminants with the environment. The different fractionation of petroleum hydrocarbons both as input to the model and as output. Concerning the fractionation of TPH, there is no protocol in Europe. Pinedo (2012) argues that the fractionation of TPH should be based on their physicochemical behavior and toxicity and not have a character of TPH as it is in the Danish model. Peters et al. (1999) suggest to focus on certain petroleum hydrocarbon fractions that are more dangerous for public health and not use a TPH approach. Park & Park (2000) are also in favor of using fractions of TPH. For the rest of the differences it cannot be said that the followed approach from a country is right or wrong as there are arguments for both sides. Regardless of the encountered difficulties in the comparison, there are three conclusions that can be drawn from the theoretical cross-examination of the methods. 1. The Swedish model has the maximum number of recipients generating guideline values for protection of humans, environment and spreading of the contaminants. 2. The Danish risk assessment is the only one that does not assess ecological risk. This is in line with the Danish Act on Contaminated Soil (Miljøministeriet 2009) 26

35 that specifically lists human safety and drinking water as the primary protective goals from contaminated areas. The Danish EPA has reflected upon the lack of the ecological risk assessment and has analyzed and compared similar models from other countries. The study and the comparison of similar models was done to prepare the ground if the pressure to change the Act on Contaminated Soil increases from the Water Framework Directive (WFD) and the Habitat Directive in EU (Miljøstyrelsen 2007 & 2012). 3. Every recipient and exposure path in the models has the same weight in the calculation of the risk deriving from the contaminated site. For example, the risk for human health is as important as the risk for the environment in the Swedish model and all the exposure paths are equated in the Norwegian and the Danish models. This means that during the use of the models no prioritization according to paths or recipients takes place Case study The results of the Swedish and the Norwegian model on the case study are considerably different. The much lower SSGVs issued by the Swedish model can be explained by the fact that more exposure paths and recipients are involved into the calculations than in the Norwegian model. If only the risk for human health was assessed by the Swedish model, the SSGVs would be higher. This conclusion is supported by the fact that 12/13 compounds in the Swedish model had the biggest influence by the exposure paths of spreading of contaminants, and not by the healthbased guideline. When the two models had the same dominating exposure path for a compound, they had their minimum difference in the SSGVs. 27

36 The lower SSGVs from the Swedish model resulted to considering the contaminant concentrations in three boreholes as potentially dangerous for human and/ or the environment. Thus, further investigation of the site can be considered. While in the case of the Norwegian model, the site complies with the SSGVs and according to the available data there is no need for further investigation. The calculations with the Danish model show a different picture for the contaminated area with all the samples giving groundwater concentrations over the drinking norms. This clear exceedance of water quality standards leads to a higher pressure for further investigation and consideration of remediation than in the case of the Swedish model. The cross-examination of the module of consumption of groundwater across the models showed how complicated such a comparison can be. In the first place it showed that the increased sensitivity of the Danish model cannot be attributed to a constant overestimation of the concentration of contaminants in the pore-water or in the groundwater. It also made clear that the disparity in the results is not related to the drinking norms. The Danish drinking norms for toluene though are remarkably more demanding than in Sweden. The Danish EPA mentions that toluene s reference values are based on the Chemical Abstract Service (Miljøstyrelsen 2014b) while the Swedish EPA uses values from World Health Organization (Naturvårdsverket 2009a). Surprisingly enough, the drinking norm for toluene in groundwater from CAS is 1 mg/l (U.S. EPA 2005) which is far greater than the mg/l that the Danish EPA uses. A possible communication with the Danish EPA could clarify this discrepancy. The overall picture from the comparison of the module of groundwater is that it is much more conservative in Denmark. Even if this exposure pathway was taken into consideration in the other two models, the concentrations of the three examined 28

37 compounds would comply with the groundwater criteria in at least 18 out of 20 samples. Another point that suggests that the Danish model is more conservative than the other two, is that a calculated concentration of contaminants in the groundwater over the quality criteria is not accepted in Denmark whereas in the Swedish model it can still be within the IGV and be accepted (as demonstrated for benzene in SB03/1). The higher tolerance in the Swedish model is supported by the fact that the drinking norms concern parts of the water network that support more than 50 people and lead to consumption of more than 10m 3 / day (Livsmedelseverket 2005). Thus not private use. Moreover, the drinking norms are not legally binding and they serve as a recommendation to help in deciding if the water is appropriate or not (Livsmedelsverket 2006). The increased sensitivity that Denmark shows for groundwater contamination is well known both inside the country (e.g. Miljøministeriet 2009; Miljøstyrelsen 2012 &2014b) and abroad (e.g. Naturvårdsverket 2006). The Danish EPA wants to guard the quality of groundwater as it constitutes the main drinking water resource in the country. The starting point of discussions for protection of groundwater is that after a simple treatment of the water with aeration and sand filtration, it should meet EU- Directive s standards (Miljøstyrelsen 2014b) Importance of the results The demonstrated divergence of the examined risk assessment methods, models and finally of the results and the conclusions that on the case-study shows how complex it is to relate contamination on a site with impact to human health and/ or to ecology. The complexity derives among other reasons from the existence of many direct and indirect exposure paths (e.g. Abrahams 2002; Chen et al. 2003; Labieniec et al. 1997; 29

38 MacLeod et al. 2004; Paustenbach 2000) and effects of multiple contaminants on site (Brouwer et al. 1990; Houk 1992; Park & Park 2010; Powers et al. 2001). Therefore it has to be further examined how updated such models are with the current state of knowledge. In practice, the displayed divergence has major implications. These differences can affect the decision to remedy a contaminated site and to prioritize remedial action among contaminated areas (e.g. Miljøstyrelsen 2011). Therefore they show interest for land-owners, consultants, the countries where the pollution occurs and, last but not least, the inhabitants that are exposed to risks that are regarded as unacceptable by a neighboring country. The land-owners of a polluted site and/ or the countries where the contaminated areas are, are legally responsible to pay for the land decontamination. In Sweden, about 1 billion SEK per year is spent on land remediation and half of it comes from the private sector. In Norway, 170 million SEK per year are allocated for the same cause (Miljøstyrelsen 2012) while in Denmark it was circa 250 million SEK in 2011 (Miljøstyrelsen 2014c). For consultants who carry out risk assessments for contaminated sites, it is obvious that the choice of a used method affects the conclusions of a risk assessment. Companies that are present as a Nordic entity have reflected upon the varying outcomes of risk assessments and the consequences they bear. The companies want to efficiently utilize their funding for land decontamination and maximize risk reduction. Additional implications for the countries from this comparison, involve which protective goals are in threat by a contaminated site as this affects the priority for 30

39 remedial action. Norway and Sweden prioritize equally the ecological and human risk assessment but they allocate more funding in remediation of sites posing risk for humans (Miljøstyrelsen 2012). Since the models may not recognize the same recipients being exposed to danger under a risk assessment, the decision that will be taken may be affected. Furthermore the risk assessments are used to see if the environmental goals set by the EPAs on a national level are met or not. In Sweden for example, the goal to have nontoxic environment (giftfri miljö) will not be met by 2020 (Naturvårdsverket 2014). But if a different risk assessment methodology was followed the results could maybe show another picture. On a European level, the same problems exist when countries report to WFD. As there is no common risk assessment methodology to gauge the environmental status of countries the results/ reports are not comparable. This inconsistency creates an uneven basis for discussions about obligations towards the WFD and will concomitantly impact the need for taken action and the associated legal implications Potential sources of errors and limitations of the results The data and the methods used in the thesis may be prone to errors and therefore pose limitations for the conclusions. The study of the risk assessment methods and models was mostly based on online material provided by the EPAs. The information though was usually fragmented in different documents even when it was issued by the same EPA. Despite the thorough research and comparison of different sources, it is possible that newer directions or guidelines may apply and have partially replaced the ones presented here. 31

40 The case-study was based on fictive data that resembled real case-studies. Thus, the construction of the examined case study by URS includes subjective choices regarding the typical presence of the contaminants and the typical geometry and characteristics of petrol stations. In order to further examine how representative is the case study and the results and the conclusions that were drawn from it, additional contaminated sites could be investigated. The common ground for comparing certain parts of the models was very limited and this investigation was one of the most time consuming elements of this study. This led to comparing only one exposure path, for three compounds, in one soil sample which corresponds to a quite small fragment of the models. Additional examination of other common features could produce more concrete results. 4. Conclusions The Swedish and the Norwegian risk assessment methods and models for contaminated land show great similarities while the Danish one differs on a conceptual level. The present case study showed that the differences between the models affect the results and the conclusions of a risk assessment. The same site can be seen as posing risk to human health in one country (Denmark), while it complies with the quality criteria of another country (Norway). The differences reflect the priorities set by the EPAs when it comes to protection goals. The implications of not having a common method and tool to assess the risk for contaminated land show great interest and mainly affect four groups: Land- 32

41 owners who may be called to cover the decontamination expenses. Consultants and companies who perform risk assessments and land remediation. The countries that have to meet national and international environmental goals and can also share/ or cover the cost for decontamination. The people who are exposed an environment seen as potential harmful by a neighboring country. Although robust conclusions were obtained for the considered case, the fact that realistic but hypothetical input data was used in the case study means that future studies would need to further address questions regarding how frequent and pronounced such diverging results are. 33

42 5. References Abrahams, P.W., 2002, Soils: Their implications to human health, The Science of the Total Environment, vol. 291, issue 1-3, p. 1-32, doi: /S (01) Brouwer, A., Murk, A.J., Koeman, J.H., 1990, Biochemical and physiological approaches in ecotoxicology, Functional Ecology, vol. 4, issue 3, p , doi: / Chen, Z., Huang, G.H., Chakma, A., 2003, Hybrid fuzzy-stochastic modeling approach for assessing environmental risks of contaminated groundwater systems, Journal of Environmental Engineering ASCE, vol. 129, issue 1, p , doi: /(ASCE) (2003)129:1(79). Cushman, D.J., Driver, K.S., Ball, S.D., Risk assessment for environmental contamination: an overview of the fundamentals and application of risk assessment at contaminated sites. Canadian Journal of Civil Engineering 28[1], NRC Research Press. doi: /cjce-28-S European Commission 2012, Guidance on the interpretation of key provisions of Directive 2008/98/EC on waste, Directorate-General Environment. European Commission 2014 Joint Research Centre (JRC), Progress in the management of Contaminated Sites in Europe, Institute for Environment and Sustainability, doi: /4658. Ferguson, C., Darmendrail, D., Freier, K., Jensen, B.K., Jensen, J., Kasamas, H., Urzelai, A. and Vegter, J. 1998, Risk Assessment for Contaminated Sites in Europe. Scientific Basis. Vol. 1. LQM Press, Nottingham. Guyonnet, D., Bourgine, B., Dubois, D., Fargier, H., Côme, B., Chilès, J., 2003, Hybrid Approach for addressing Uncertainty in Risk Assessments, Journal of 34

43 Environmental Engineering-ASCE, vol. 129, issue 1, p , doi: /(ASCE) (2003)129:1(68). Houk, V.S., 1992, The genotoxicity of industrial wastes and effluents, Mutation Research, vol. 277, issue 2, p , doi: / (92)90001-P. Labieniec, P.A., Dzombak, D.A., Siegrist, R.L., 1997, Evaluation of uncertainty in site-specific risk assessment, Journal of Environmental Engineering ASCE, vol. 123, Issue 3, p , doi: /(ASCE) (1997)123:3(234). Li Jianbing, Huang H. Gordon, Zeng Guangming, Maqsood Imran, Huang Yuefei, 2007, An integrated fuzzy-stochastic modeling approach for risk assessment of groundwater contamination, Journal of Environmental Management, vol. 82, issue 2, p , doi: /j.jenvman Linkov, I., Loney, D., Cormier, S., Satterstrom, F.K., Bridges, T., 2009, Weight-ofevidence evaluation in environmental assessment: Review of qualitative and quantitative approaches, Sciences of the Total Environment, vol. 407, issue 19, p , doi: /j.scitotenv Livsmedelsverket Swedish National Food Agency 2006, Vägledning till Livsmedelsverkets föreskrifter om dricksvatten (SLVFS 2001:30) [Guidance for Swedish National Food Agency s regulations for drinking water (SLVFS 2001:30)] (In Swedish), Tillsynsavdelningen, Enheten för inspektion. MacLeod, M., McKone, T.E., Foster, K.L., Maddalena, R.L., Parkerton, T.F., MacKay, D., 2004, Applications of Contaminants and Bioaccumulation Models in Assessing Ecological Risks of Chemicals: A Case Study for Gasoline Hydrocarbons, Environmental Science & Technology. vol 38, p doi: /es Miljøministeriet - Danish Ministry of the Environment 2009, Bekendtgørelse af lov om forurenet jord LBK nr 1427 af 04/12/2009 [Act on Contaminated Soil (No of 2009)] (In Danish). 35

44 Miljøstyrelsen - Danish Environmental Protection Agency 2002, Guidelines on remediation of contaminated sites, Environmental guidelines no 7. Miljøstyrelsen - Danish Environmental Protection Agency 2007, Consolidating Regulation No. 282 on Contaminated Soil, LBKG Miljøstyrelsen - Danish Environmental Protection Agency 2011, Værktøjer til brug for risikovurdering og prioritering af grundvandstruende forureninger [Tool for risk evaluation and prioritization of threat for groundwater pollution] (In Danish), Environmental Project , Teknologiprogrammet for jord- og grundvandsforurening. Miljøstyrelsen - Danish Environmental Protection Agency 2012, Ecological risk assessment of contaminated sites, Environmental project Miljøstyrelsen - Danish Environmental Protection Agency 2013, Manual for program til risikovurdering JAGG 2.0 (in Danish), Environmental project Miljøstyrelsen - Danish Environmental Protection Agency 2014a, Bilag til redegørelse om jordforurening 2011, [Appendix of remediation of contaminated land 2011] (in Danish). Miljøstyrelsen - Danish Environmental Protection Agency 2014b, Liste over kvalitetskriterier i relation til forurenet jord og kvalitetskriterier for drikkevand, [List of quality criteria concerning contaminated soil and quality criteria for drinking water] (in Danish). Miljøstyrelsen - Danish Environmental Protection Agency 2014c, Redegørelse om Jordforurening 2011 [Statement in soil pollution 2011] (In Danish). Miljøverndepartementet Norwegian Environmental Protection Agency 1999, Veiledning om risikovurdering av forurenset grunn [Directions for risk evaluation of polluted wells] (In Norwegian). Norwegian Pollution Control Authority. Guidance 99:01a. 36

45 Miljøverndepartementet Norwegian Environmental Protection Agency 2009, Helsebaserte tilstandsklasser for forurenset grunn [Health based classes of environmental state for polluted wells] (In Norwegian). Norwegian Pollution Control Authority. Guidance TA Naturvårdsverket Swedish Environmental Protection Agency 2002, Methods for inventories of Contaminated Sites. Naturvårdsverket Swedish Environmental Protection Agency 2006, Fördjupade riskbedömningar. Erfarenheter av riktvärdesberäkningar och användning av ny kunskap [Advanced risk assessments. Experiences from generation of guideline values and use of gained knowledge] (In Swedish). Report Naturvårdsverket Swedish Environmental Protection Agency 2009a, Riktvärden för förorenad mark [Guideline values for contaminated soil] (In Swedish). Report Naturvårdsverket Swedish Environmental Protection Agency 2009b, Riskbedömning av förorenade områden [Risk assessment for contaminated sites] (In Swedish). Report Naturvårdsverket Swedish Environmental Protection Agency 2014, Miljömålen Årlig uppföljning av Sveriges miljökvalitetsmål och etappmål 2014 [Environmental goals Annual follow-up of Swedish environmental quality and interim goals] (in Swedish). Report NICOLE, Network for Industrially Contaminated Land in Europe, 2004, Risk Assessment Comparison Study, NICOLE Project, Appendix F Part 1. Park, In-Sun, Park, Jae-Woo, 2000, A novel total petroleum hydrocarbon fractionation strategy for human health risk assessment for petroleum hydrocarboncontaminated site management, Journal of Hazardous Materials, vol. 179, issue 1-3, p , doi: /j.jhazmat

46 Paustenbach, D.J., 2000, The practice of exposure assessment: A state-of-the-art review, Journal of Toxicology and Environmental Health, Part B: Critical Reviews, 3:3, p , doi: / Peters, C.A., Knightes, C.D., Brown, D.G., 1999, Long-Term Composition Dynamics of PAH-Containing NAPLs and Implications for Risk Assessment, Environmental Science & Technology, vol. 33, issue 24, p , doi: /es981203e. Powers, S.E., Hunt, C.S., Heermann, S.E., Corseuil, H.X., Rice, D., Alvarez, P.J.J., 2001, The Transport and Fate of Ethanol and BTEX in Groundwater Contaminated by Gasohol, Critical Reviews in Environmental Science and Technology, Vol. 31, Issue 1, p Doi: / Pinedo, J., Ibanez, R. Prima, O. and Irabien Gulias, A., 2012, Hydrocarbons Analysis for Risk Assessment in Polluted Soils, Chemical Engineering Transactions, The Italian Association of Chemical Engineering, Vol. 28, p doi: /CET Suter II, G.W., 2006, Ecological Risk Assessment. CRC Press, Boca Raton, USA. Thompson, K.M., Burmaster, D.E., Crouch, E.A.C., 1992, Monte Carlo Techniques for Quantitative Uncertainty Analysis in Public Health Risk Assessments, Risk Analysis, vol. 12, issue 1, p , doi: /j tb01307.x. Troldborg, M., 2010, Risk assessment models and uncertainty estimation of groundwater contamination from point sources, PhD thesis, Technical University of Denmark. U.S. EPA - United States Environmental Protection Agency, 2005, Toxicological review of toluene. CAS No Van Straalen, N.M., 2002, Assessment of soil contamination, Biodegradation, vol. 13, issue 1, p , doi: /A:

47 6. Appendix Fig. 1. Map of the hypothetical petrol station. The location of the boreholes is designated with black circles accompanied by the code of the bore sample. The outline of the buildings is marked with grey. 39

48 Table 1. Chemical analysis from the soil samples at the petrol station. The lab results refer to the concentration of 72 compounds in soil (left side) at ten boreholes (SB01-SB12). Each borehole has two samples at different depths e.g. SB01/1 and SB01/2 for borehole SB01. Concentrations are given in mg/kg dry weight soil. Substance Sample SB01/01 SB01/02 SB03/01 SB03/02 SB04/01 SB04/02 SB05/01 SB05/02 SB06/01 SB06/02 SB07/01 SB07/02 SB08/01 SB08/02 SB10/01 SB10/02 SB11/01 SB11/02 SB12/01 SB12/02 Limit of Depth (m) detection (mg/kg) Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aliphatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C

49 Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Aromatic hydrocarbons C Bensen Toluene Etylbensen m-xylen o-xylen p-xylen Xylener MtBE

50 Table 2. Configuration and report of the Swedish model Konceptuell förorenings- och spridningsmodell Naturvårdsverket, version 1.00 I detta blad kan en konceptuell förorenings- och spridningsmodell utarbetas för ett objekt. Vägledning för hur denna tas fram finns i Naturvårdsverkets rapport Riskbedömning av förorenade områden (rapport 5977), se Avsikten är att initialt göra en kvalitativ bedömning av vilka föroreningskällor, frigörelsemekanismer, spridningsvägar, möjliga exponeringsvägar och skyddsobjekt som är aktuella och behöver beaktas i projektet. En del av exponeringsvägarna kan beräkningsprogrammet hantera (röd text nedan). Risker kopplade till andra exponeringsvägar måste hanteras utanför programmet. Den konceptuella modellen kan användas som underlag vid diskussioner mellan olika parter i projektet. Återställ formulär Eget scenario: Generellt scenario: MKM Gas station MKM Frigörelse-/ Föroreningskällor spridningsmekanismer Exponeringsvägar Skyddsobjekt Ytlig mark- Utlakning till Hudkontakt Människor Miljö Naturresurser förorening grundvatten och jord ytvatten Djupt liggande Intag av jord markförorening Spridning via Boende på platsen: Mark- Grundvatten grundvatten -Vuxna ekosystem Inandning -Barn Markförorening damm under grund- Spridning via vattenyta ytvatten Regelbundet verk- Inandning av samma på platsen: ånga från jord -Vuxna Förorening Förångning -Barn Ytvatten- Ytvatten i grundvatten ekosystem Intag av dricks- Vinderosion vatten Besökande: Förorening -Vuxna i sediment -Barn Vattenerosion, Intag av frukt, ras och skred bär, svamp, Förorening rot- & grönsaker Närboende: som fri fas -Vuxna Sediment- Övrigt Frifasspridning -Barn ekosystem Intag av fisk Förorening finns i/omkring: Upptag i växter Övrigt -Lagringstankar Bevattning -Rörledningar -Avfall/deponi Övrigt -Ledningsgravar Intag av mjölk, -Övrigt kött och ägg Övrigt Pågående verksamhet Hudkontakt med sediment Övrigt Övrigt 42

51 Indata för beräkning av riktvärden Naturvårdsverket, version 1.00 Val av generellt scenario (gulbruna celler) Beskrivning av scenariot Scenariots namn: MKM Gas station Hämta generellt scenario: Beskrivning: Standardscenario för mindre känslig markanvändning, enligt Naturvårdsverkets generella riktvärden för förorenad mark. Val av eget scenario (data till vita inmatningsceller) Hämta eget scenario: Val av ämnen Ämne 1: Ämne 2: Ämne 3: Ämne 4: Ämne 5: Ämne 6: Ämne 7: Ämne 8: Ämne 9: Ämne 10: Ämne 11: Ämne 12: Ämne 13: Ämne 14: Ämne 15: Ämne 16: Ämne 17: Ämne 18: Ämne 19: Ämne 20: Ämne 21: Ämne 22: Ämne 23: Ämne 24: Val av exponeringsvägar Intag av jord Hudkontakt med jord/damm Inandning av damm Inandning av ånga Intag av dricksvatten Intag av växter Uppskattning av halt i fisk Scenariospecifika modellparametrar Använd KM-värden i modellen Använd MKM-värden i modellen Exponeringsparametrar Intag av förorenad jord MKM Exponeringstid barn dag/år Exponeringstid vuxna dag/år Hudkontakt med jord/damm Exponeringstid barn dag/år Exponeringstid vuxna dag/år Inandning av damm Exponeringstid barn dag/år MKM Exponeringstid vuxna dag/år Andel inomhusvistelse Inandning av ånga Exponeringstid barn dag/år Exponeringstid vuxna dag/år Andel inomhusvistelse Intag av växter Konsumtion, barn 0 0 kg/dag Konsumtion, vuxna 0 0 kg/dag Andel från odling på plats Jord- och grundvattenparametrar MKM Förorenat område Halt löst/mobilt organiskt kol kg/dm 3 MKM Torrdensitet kg/dm 3 Områdets längd m Halt organiskt kol kg/kg Områdets bredd m Vattenhalt dm 3 /dm 3 Riktvärdet avser endast jord under Andel porluft dm 3 /dm 3 grundvattenytan Total porositet 0.4 dm 3 /dm 3 Mäktighet under gv-ytan 1 m 43