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Possible Control of EU Priority Substances in Danish Waters 2 Technical analysis and assessment
2.1 IntroductionMuch of the technical description and analysis of the current situation of each of the priority substances presented in this report was made already in the screening project mentioned in Chapter 1, which was conducted in 2004-2005. The results of the screening project are presented in a separate report. However, some updating and further elaboration of the information and data from the screening report was carried out as part of the current project using publicly available literature although the emphasis was on identifying measures to reduce the current discharges, emissions and losses, where necessary, and to assess the economic consequences to society, private enterprises and consumers. Whereas the screening project addressed all 33 priority substances established by Decision no. 2455/2001/EC, this project has focused strictly on the substances for which the screening project found that the current concentrations in discharges into or in the aquatic environment itself most likely exceed the environmental quality objectives (EQS) proposed in the draft Daughter Directive. A brief summary and overview of the main findings and conclusions of the screening project are presented in Section 2.2 below. The subsequent sections of this chapter address the scope and delimitation of the project with respect to the various sub-groups of substances included in the Daughter Directive proposal and present the principles applied to assess the compliance of each of the selected substances with the proposed EQS. As mentioned in Chapter 1, Introduction, work was carried out in two phases; Phase 1 in the autumn of 2005 based on a draft version of the Daughter Directive proposal and Phase 2 in the summer-early autumn of 2006 based on the official proposal. The main changes of the official Daughter Directive proposal (COM(2006) 397 final) compared with the 2005 draft are the following:
2.2 Screening of the 33 priority substancesA national screening level review of consumption, uses, current environmental regulation, pollution sources and occurrence in the aquatic environment was conducted in 2004-2005 for the 33 priority substances established under the Water Framework Directive" (WFD; 2000/60/EC) by the Parliament's and the Council's Decision no. 2455/2001/EC. The aim of the screening was to clarify to what extent further national regulatory measures were likely to be needed in relation to an anticipated WFD Daughter Directive on these substances /1/. At the time of the screening only the unofficial draft proposals for the annual average (AA) and maximum acceptable concentration (MAC) values of the environmental quality standards (AA-EQS and MAC-EQS, respectively) for the 33 substances were known while other possible requirements to be included in the directive were still under consideration by the Commission. Table 2-1 provides an overview of the 33 priority substances together with an assessment of their "relevance", i.e. the possible need for further national regulation in Denmark based on the results of the screening level review. For 10 of the 33 substances it was assessed that it would be relevant for Denmark to evaluate the need for and/or type of further national regulation more thoroughly because there is documentation or strong indications that these substances may occur in the Danish aquatic environment in concentrations above the proposed EQS. A "strong indication" is e.g. if a substance often occurs in wastewater discharges in concentrations significantly higher than the proposed EQS. The substances thus singled out do not necessarily pose a problem in all discharges or in the aquatic environment in general, but on the other hand, they are not limited to just a few special cases. For these substances, it is considered likely that action by Denmark will be required due to the forthcoming Daughter Directive. As for 20 substances, it was assessed that further national regulatory measures would not be relevant as the substances are not produced or used in Denmark and/or because the concentrations in discharges into the aquatic environment are already now significantly below the proposed EQS values. Another 3 substances probably belong to this category as well, but some reservations about the assessment had to be made due to lack of concrete data. It could not be excluded that for a few of these 23 substances, there are specific cases where a discharge would result in a local violation of the EQS. For some of the 10 substances singled out as possible items for further national action, it was found that the possible measures required to comply with the EQS would have to address aquatic pollution of a purely historical character as the necessary regulation of uses (including total bans) of the substances in question was already implemented. Table 2-1 Overview of the 33 priority substances under the Water Framework Directive including an assessment of the needs for further national regulation in Denmark.
2.3 The selected priority substances2.3.1 Priority substancesBased on the outcome of the screening project the following 8 (10) priority substances were selected for further analysis and assessment of the economic consequences of implementing the necessary measures to comply with the EQS and other anticipated requirements of the final Daughter Directive:
In the screening project 10 substances were pointed out for further analysis and assessment. However, two of the selected substances - anthracene and fluoranthene - were not found to require further action as single substances but only in relation to general actions targeted at the PAH group. Chemically, anthracene and fluoranthene belong to the group of polycyclic aromatic hydrocarbons (PAHs) though not formally included in the list of substances representing this group in the Daughter Directive. Therefore, in reality the current study only comprises 8 substances/groups of substances. 2.3.2 Priority hazardous substancesThe final Daughter Directive proposal identifies 13 of the 33 priority substances (PS) as priority hazardous substances (PHS) for which certain, stricter requirements apply, mainly for controls to ensure "the cessation or phasing out of discharges, emissions and losses of priority hazardous substances", irrespective of whether these substances are assessed to comply with the EQS or not (according to the Water Framework Directive). Among the PS identified for possible further national action in Denmark, the following 6 are also defined as PHS:
Thus, among the PS selected for this study only DEHP, fluoranthene, lead and nickel are not PHS. 2.4 The not-selected priority substancesAs mentioned in Section 2.2, the screening project found that 23 out of the 33 priority substances included in the final Daughter Directive proposal would require further national measures/actions in order to comply with the EQS values proposed at that time. A brief, updated assessment of these 23 substances in relation to the Commission's official directive proposal is made in Chapter 12. 2.5 Losses of priority hazardous substances from contaminated sitesAccording to the Water Framework Directive cessation of "losses" of priority hazardous substances to the aquatic environment should eventually be achieved by means of appropriate control measures, where needed. Such "losses" are considered to occur predominantly as a result of seepage or leaching of the substances from contaminated (historical or present) industrial sites or depots located adjacent or close to surface waters or at locations with very permeable sub-surface layers. Presently, almost 20,000 contaminated sites have been registered in Denmark /2/ of which, however, the majority are small sites. Further, most sites and depots are thought to be located at some distance from surface water bodies thus rendering the risk of surface contamination insignificant. A few major sites in the vicinity of streams, lakes or the coast do exist. 11 major sites have been identified at which the cost of remediation is estimated to exceed DKK 30 million. At 7-8 out of the 11 sites, surface water bodies are known to be contaminated already or considered to be at risk. At some of the sites the pollution may comprise one or more of the priority hazardous substances covered by the Daughter Directive e.g. cadmium, mercury and PAH. However, actions to eliminate the pollution from these sites are already planned or even ongoing. The (by far) most common types of contamination are various types of oil, gasoline and various solvents including those used for dry cleaning. Also, heavy metal contamination of soil is frequently reported but rarely in relation to risk to surface waters. Data on other specific contaminants are difficult to extract from published, aggregated reports on the subject, and it will require a more focused, in-depth analysis to determine to what extent PHSs are part of the problem. Overall, it is the impression that the major loads of contaminants into surface waters in Denmark originate from emissions or discharges while only a minor part is the result of seepage/leaching from contaminated sites of which the largest are being addressed already. However, it was decided to verify this assessment through a special study on the issue, which will be reported separately. The study will also include an assessment of extent to which the proposed EQS values for inland or other surface waters are exceeded as a result of impact from contaminated sites. This is not possible to extract from the mentioned report on the state of soil contamination in Denmark /2/. 2.6 Priority hazardous substances in biotaArticle 2.3 of the officially proposed Daughter Directive defines maximum allowable concentrations in biota for three PHSs, i.e. concentrations which must not be exceeded in prey tissue (wet weight; ww) of fish, molluscs, crustaceans and other biota: a. 10 μg/kg ww for hexachlorobenzene (HCB), b. 55 μg/kg ww for hexachlorobutadiene (HCBD), c. 20 μg/kg ww for methyl-mercury. In 2005, the Danish Veterinary and Food Administration (DVFA) published monitoring data for HCB and mercury (but not methyl-mercury) for a significant number of food items, including some fish species /3/. For HCB, all data on whole fish (mainly marine species) show compliance at the 90 % percentile level with the proposed maximum concentration of 10 μg HCB/kg ww. Only the content of HCB in cod liver (in which a lipophile substance such as HCB is concentrated) from certain parts of the Danish marine environment (the Baltic Sea, the Sound and the Belts) exceeds the limit value with up to a factor of 2.3 (90 % percentile, Baltic Sea). The National Environmental Research Institute (NERI) recently presented data on HCB in liver from flatfish caught in different parts of Denmark /4/. The levels range from 0.7 to 1.8 μg HCB/kg ww, i.e. well below the limit value. Overall, the present HCB levels in biota are considered to comply with the limit value. No Danish monitoring data on methyl-mercury in aquatic biota have been identified but according to UNEP's "Global Mercury Assessment" (/5/) "The US EPA states in an updated mercury overview paper that in most adult fish, 90 to 100 percent of the mercury content is methyl mercury". Therefore, the total content of mercury in fish as reported in the "Chemical contaminants" report by the DVFA (/3/) is considered to provide a fully satisfactory picture of the situation. The following concentrations of total mercury (90 % percentile of data) were reported for some of the most common fish species (whole fish): Cod: 94.7 μg/kg ww (30 samples), Herring: 64.5 μg/kg ww (18 samples), and Plaice: 72.4 μg/kg ww (21 samples). As the proposed limit value for methyl mercury is only 20 μg/kg ww, and as also the median concentrations of mercury in the same three species exceeded this value, it is concluded that presently the (methyl) mercury levels in aquatic biota in Denmark cannot presently be considered as compliant with the requirements in the proposed new Daughter Directive. As the contamination appears to be widespread, on-site clean-up will not be possible, and the only way of actively contributing to a reduction of the current mercury levels in biota is then to further control the existing sources. Possible actions to reduce the emissions and discharges of mercury in Denmark are described and assessed in Chapter 7. HCBD has never been monitored in biota in Denmark but the substance has no use in Danish industry, and it was deleted from the national surveillance programme for the aquatic environment and nature (NOVA2003, now NOVANA) because the first rounds of monitoring consistently showed that the concentrations (in water) were below the detection limit. It is therefore considered very unlikely that HCBD should occur in biota at levels equal to or higher than the limit value. 2.7 Other pollutantsThe final Daughter Directive also establishes EQSs for a number of "other pollutants" (Annex I, Part B), i.e. some chemicals that are not priority substances but substances which were previously included in a number of directives that will be repealed by 2013 (Directives 82/176/EEC, 83/513/EEC, 84/456/EEC, 84/491/EEC and 86/280/EEC). The substances included in this group are:
The first five are chlorinated insecticides, which have not been used or permitted for use in Denmark for a considerable number of years, while the three last substances are aliphatic chlorinated solvents of which carbon tetrachloride has only had very restricted use for many years while the two others have been used extensively until rather recently (and are still being used). Among the chlorinated insecticides, isodrin has never been used in Denmark, while aldrin and endrin have not been on the market since 1963 and heptachlor not since 1972. DDT was banned for agricultural uses in 1970 and other uses were completely banned in 1984. Dieldrin was used in certain wood preservation products until 1988 when it was completely banned for use in Denmark. For a number of years, chlorinated insecticides were included in the point source part of the national surveillance programme for the aquatic environment, NOVA 2003, but were left out when the programme was revised in 2002-2003 (to become the present NOVANA programme) because the levels had been under the detection limit of 0.01 μg/L in practically all samples during the preceding period. Trichloroethylene and tetrachloroethylene are both included in the point source part of the NOVA 2003/NOVANA programme while carbon tetrachloride has been omitted due to its insignificant use. The proposed AA_EQS is 10 μg/L for both substances (and 12 for carbon tetrachloride). In the 2003 survey report of the NOVA 2003 programme the 95 % percentile of effluent measurements at 30 wastewater treatment plants was 0.07 μg/L for trichloroethylene and 0.08 μg/L for tetrachloroethylene while the 95 % percentile of the influent concentrations was 0.7 and 0.5 μg/L respectively/7/. As WWTP effluents are considered to be the main source of contamination of the aquatic environment with these substances, none of the substances are believed to exceed the proposed EQS values for surface waters. 2.8 Principles for assessment of EQS complianceThe priority substances must, when they occur in inland, transitional or coastal surface waters, at all times comply with the MAC-EQS established and on the average over a period of one year comply with the AA-EQS. However, often data on the occurrence of the PS defined under the Daughter Directive in aquatic environment are very sparse or completely absent while some data on the concentration of the substances in various discharges and emissions, primarily of sewage effluent and stormwater from separate systems, exist. Hence, in many cases the assessment of EQS compliance must rely on an interpretation of such data rather than being based on monitoring data from surface waters. For this purpose the following principles have been applied:
2.9 References/1/ Kjølholt J, Winther Ringgaard K, Skårup S (2006). Kilder og miljøtilstand for prioriterede stoffer under Vandrammedirektivet. Miljøprojekt nr. XXXX (in press). Danish Environmental Protection Agency. /2/ DEPA: "Redegørelse om jordforurening 2004", Redegørelse Nr. 4 fra Miljøstyrelsen, 2005. /3/ DVFA (2005). Chemical contaminants. Food monitoring, 1998-2003. Part 1. /4/ NERI (2006). Hazardous substances and heavy metals in the aquatic environment. State and trends, 1998-2003. The National Environmental Research Institute, Report no. 585, 2006. /5/ UNEP (2002). Global Mercury Assessment. UNEP Chemicals, Geneva, 2002. /6/ Miljøstyrelsen (2002). Udledning af miljøfarlige stoffer med spildevand. Miljøprojekt nr. 690, Miljøstyrelsen 2002. /7/ Miljøstyrelsen (2004). Punktkilder 2003. Orientering nr. 16, 2004 fra Miljøstyrelsen.
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