Table of contents Glossary Abbreviations 1. Introduction: Purpose and scope of the Evaluation 2. Background to the intervention 2.1. Description of the intervention and its objectives 2.2. Baseline and point of comparison 3. State of play 4. Method 4.1. Literature review 4.2. Stakeholder consultation 4.3. Modelling 4.4. Limitations and robustness of findings 5. Analysis 5.1. Effectiveness 5.2. Efficiency 5.3. Coherence 5.4. Relevance 5.5. EU added value

6. Conclusions Annex 1: Procedural information Annex 2: Stakeholder consultation Key issue interviews Public consultation Thematic expert workshops Stakeholder conference Written consultation Annex 3: Methods and analytical models 1. Science for Policy – the effects of the UWWTD 2. Cost and benefits Approach to modelling costs Approach to modelling benefits Annex 4: Supporting evidence Overview: Mapping of replies to Evaluation questions Implementation Effectiveness Efficiency Coherence Relevance

Annex 5: References Glossary Term Explanation Agglomeration According to the UWWTD: ‘Agglomeration’ means an area where the population and/or economic activities are sufficiently concentrated for urban waste water to be collected and conducted to an urban waste water treatment plant or to a final discharge point. (Article 2(4)). An agglomeration can be a city or municipality, but it can also be a number of smaller cities or towns clustered together. Biochemical oxygen demand According to the UWWTD: In the waste water discharge, biochemical oxygen demand (BOD) needs to be reduced to 25mg/l O2 or a minimum reduction of 70-90% needs to be achieved. (Annex I). BOD is ‘the amount of dissolved oxygen used by micro-organisms in the biological process of metabolising organic matter in water. The more organic matter there is (e.g. in sewage and polluted bodies of water), the greater the BOD; and the greater the BOD, the lower the amount of dissolved oxygen available for higher animals such as fishes. The BOD is therefore a reliable gauge of the organic pollution of a body of water. One of the main reasons for treating waste water prior to its discharge into a water resource is to lower its BOD—i.e., reduce its need of oxygen and thereby lessen its demand from the streams, lakes, rivers, or estuaries into which it is released.’ Britannica (2019a). BOD is most commonly expressed as milligrams of oxygen consumed per litre of samples over 5 days of incubation at 20°C – this is called BOD5 (Sawyer et al., 2003). In this text “BOD” means “BOD5”. Chemical oxygen demand The UWWTD states that chemical oxygen demand (COD) in the waste water discharge needs to be reduced to 125mg/l O2. Alternatively, a minimum reduction of 75% needs to be achieved. (Annex I). COD ‘is a second method of estimating how much oxygen would be depleted from a body of receiving water as a result of bacterial action. While the BOD test is performed by using a population of bacteria and other microorganisms to attempt to duplicate what would happen in a natural stream over a period of five days, the COD test uses a strong chemical oxidising agent (potassium dichromate or potassium permanganate) to chemically oxidise the organic material in the sample of waste water under conditions of heat and strong acid.’ (Woodard & Curran, 2006). Collection system The UWWTD defines this as a system of conduits which collects and conducts urban waste water. (Article 2(5)). Combined sewers In the UWWTD: The UWWTD allows for the use of combined and separate sewers. Combined sewers: ‘Systems that carry a mixture of both domestic sewage and storm sewage are called combined sewers. Combined sewers typically consist of large-diameter pipes or tunnels, because of the large volumes of storm water that must be carried during wet-weather periods. They are very common in older cities but are no longer designed and built as part of new sewerage facilities.’ (Britannica, 2019b). Contaminants of emerging concern In the UWWTD: The UWWTD does not include a reference to contaminants of emerging concern. According to the Organisation for Economic Co-operation and Development (OECD) “Contaminants of emerging concern (CECs) comprise a vast array of contaminants that have only recently appeared in water, or that are of recent concern because they have been detected at concentrations significantly higher than expected, or their risk to human and environmental health may not be fully understood. Examples include pharmaceuticals, industrial and household chemicals, personal care products, pesticides, manufactured nanomaterials, and their transformation products’ (OECD, 2018). The Environmental Quality Standards D irective explains pollutants of emerging concern. Recital 26 states that ‘emerging pollutants … can be defined as pollutants currently not included in routine monitoring programmes at Union level but which could pose a significant risk requiring regulation, depending upon their potential ecotoxicological and toxicological effects and on their levels in the aquatic environment.’ Diffuse sources The E-PRTR Regulation (EC) No 166/2006 gives the following definition of diffuse sources: ‘“diffuse sources” means the many smaller or scattered sources from which pollutants may be released to land, air or water, whose combined impact on those media may be significant and for which it is impractical to collect reports from each individual source’. Diffuse sources include agricultural activities, some urban-related emissions, atmospheric deposition, and rural dwellings. Typically, they are more variable in space and time than point sources. (EC, 2012a). Eutrophication UWWTD definition: The enrichment of water by nutrients, especially compounds of nitrogen and/or phosphorus, causing an accelerated growth of algae and higher forms of plant life to produce an undesirable disturbance to the balance of organisms present in the water and to the quality of the water concerned. (Article 2(11)). Individual or other appropriate systems The UWWTD states that ‘where the establishment of a collecting system is not justified either because it would produce no environmental benefit or because it would involve excessive cost, individual systems or other appropriate systems which achieve the same level of environmental protection shall be used.’ (Article 3(1)). Microplastics According to the European Chemicals Agency (ECHA), ‘the term “microplastic” is not consistently defined, but is typically considered to refer to small, usually microscopic, solid particles made of a synthetic polymer. They are associated with long-term persistence in the environment, if released, as they are very resistant to (bio)degradation.’ (ECHA, 2019). More stringent treatment More stringent treatment or tertiary treatment is the third stage of treatment and can consist of nutrient removal, chemical or physical disinfection (by lagoons or microfiltration). In the UWWTD, table 2 in Annex I lays down the thresholds for nutrient reduction. Point sources According to Common Implementation Strategy Technical Report No. 28: ‘A point source is a single localised point of discharge of waste water containing one or more pollutant(s). The most important ones are industrial facilities, waste water treatment plants (although strictly speaking the plant itself is not the source), untreated sewage, waste disposal systems and mining sites.’ (EC, 2016). Population equivalent UWWTD definition: ‘1 p.e. (population equivalent)’ means the organic biodegradable load having a five-day biochemical oxygen demand (BOD5) of 60 g of oxygen per day.’ This means: 1 p.e. broadly corresponds to the average pollution release of one person in one day and describes the pollution load contained in waste water. Primary treatment UWWTD definition: ‘Primary treatment’ means treatment of urban waste water by a physical and/or chemical process involving settlement of suspended solids, or other processes in which the BOD of the incoming waste water is reduced by at least 20% before discharge and the total suspended solids of the incoming waste water are reduced by at least 50%. (Article 2(7)). Secondary treatment UWWTD definition: ‘Secondary treatment’ means treatment of urban waste water by a process generally involving biological treatment with a secondary settlement or other processes in which the requirements established in Table 1 of Annex I are respected. (Article 2(8)). Separate sewers The UWWTD allows for the use of combined and separate sewers. Separate systems: “New waste water collection facilities are designed as separate systems, carrying either domestic sewage or storm sewage but not both. Storm sewers usually carry surface runoff to a point of disposal in a stream or river. Small detention basins may be built as part of the system, storing storm water temporarily and reducing the magnitude of the peak flow rate. Sanitary sewers, on the other hand, carry domestic waste water to a sewage treatment plant. Pretreated industrial waste water may be allowed into municipal sanitary sewerage systems, but storm water is excluded.” (Britannica, 2019c). Storm Water Overflows A footnote in Annex I to the UWWTD contains states ‘…during situations such as unusually heavy rainfall, Member States shall decide on measures to limit pollution from storm water overflows. Such measures could be based on dilution rates or capacity in relation to dry weather flow or could specify a certain acceptable number of overflows per year.’ As mentioned under combined sewers, these systems carry waste water and storm water. According to Britannica, ‘because wastewater treatment plants cannot handle large volumes of storm water, sewage must bypass the treatment plants during wet weather and be discharged directly into the receiving water. These combined sewer overflows, containing untreated domestic sewage, cause recurring water pollution problems and are very troublesome sources of pollution.’ (Britannica, 2019b). Surface water Water Framework Directive definition: Inland waters, except groundwater; transitional waters and coastal waters, except in respect of chemical status for which it shall also include territorial waters. (Article 2(1)). (Total) nitrogen UWWTD definition: Total nitrogen means: the sum of total Kjedahl nitrogen (organic and ammoniacal nitrogen), nitrate-nitrogen and nitrite-nitrogen. The UWWTD requires a reduction of total nitrogen in waste water discharges to concentrations of 15 mg/1 N (10 000 - 100 000 p.e.) and 10 mg/1 N (more than 100 000 p.e.). (Annex I). Why nitrogen: Nitrogen is, together with phosphorus, one of the main nutrients in waste water. Nitrogen becomes ammonia/ammonium, creating an additional oxygen demand. This can lead to excessive plant and algae growth, which can then prevent other organisms from living and growing. (Total) phosphorus In the UWWTD: The UWWTD requires a reduction of total phosphorus in waste water discharges to concentrations of 2 mg/1 P (10 000 - 100 000 p. e.) and 1 mg/1 P (more than 100 000 p.e.). (Annex I). Why phosphorus: Together with nitrogen, phosphorus is one of the main nutrients in waste water. Phosphorus becomes ortho-phosphate, creating an additional oxygen demand. This can lead to excessive plant and algae growth, which can then prevent other organisms from living and growing. Urban waste water The UWWTD defines ‘urban waste water’ as domestic waste water on its own or domestic waste water mixed with industrial waste water and/or runoff rain water. (Article 2(1)). Abbreviations Term or abbreviations Meaning or definition AMR Anti-microbial resistance BWD Bathing Water Directive BOD Biochemical oxygen demand COD Chemical oxygen demand DWD Drinking Water Directive CJEU Court of Justice of the European Union CSO Combined sewer overflow EC European Commission ECA European Court of Auditors ECHA European Chemicals Agency EEA European Environment Agency E-PRTR European Pollutants Release and Transfer Register EQS Environmental quality standards GHG Greenhouse gas GWh Gigawatt hours IAS Individual or other appropriate system IED Industrial Emissions Directive IPCC Intergovernmental Panel on Climate Change JRC European Commission Joint Research Centre MSFD Marine Strategy Framework Directive N Nitrogen ND Nitrates Directive NVZ Nitrates vulnerable zones O&M Operation and maintenance costs OECD Organisation for Economic Cooperation and Development P Phosphorus p.e. Population equivalent PIE strategic approach Strategic approach to pharmaceuticals in the environment RBMP River basin management plan REACH Registration, evaluation, authorisation and restriction of chemicals RTC Real time control SIIF Structured implementation and information framework SSD Sewage Sludge Directive SVHC Substance of very high concern SWO Storm water overflow TSS Total suspended solids UWWTD Urban Waste Water Treatment Directive UWWTD EG Urban Waste Water Treatment Directive Expert Group WFD Water Framework Directive WIND What if no Directive scenario Water Fitness Check Fitness Check of the Water Framework Directive, the Groundwater Directive, the Environmental Quality Standards Directive, and the Floods Directive WTP Willingness to Pay WSS Water Supply and Sanitation WWTP Waste Water Treatment Plant 1.Introduction: Purpose and scope of the Evaluation The Urban Waste Water Treatment Directive (UWWTD) was adopted in 1991. Although the Directive does not include a requirement for its own review, developments over the past three decades call for its Evaluation. The Directive was partially subject to evaluation in the Water Blueprint of 2012 (EC, 2012a; EC, 2012b), which concluded that rates of compliance with the UWWTD needed to be improved through better investment and implementation plans. Thanks to the independent Evaluation presented here, the extent to which the Directive is working effectively has been analysed in depth. As part of the Regulatory Fitness and Performance programme (REFIT), it assesses whether the Directive is fit for purpose. As set out in the Evaluation’s Roadmap (EC, 2017), the Evaluation considers the entire Directive, the full period of its implementation, and all EU Member States. The Evaluation is closely coordinated with the Water Fitness Check . It also takes into account the Strategic approach to pharmaceuticals in the environment (EC, 2019) and the Plastics strategy (EC, 2018), which require certain aspects of the UWWTD to be evaluated. 2.Background to the intervention 2.1.Description of the intervention and its objectives Contextualisation: water pollution affecting the quality of water bodies Humans and all other living organisms need clean water to survive. Humans need clean water for drinking and sanitary purposes, as well as for economic activities such as energy production, manufacturing, transport, tourism and fishing. Water is central to most natural ecosystems, and polluted water bodies can lead to damaged aquatic and terrestrial environments no longer able to provide the ecosystem services that society depends on. Water quality can be affected by point and diffuse pollution sources, such as industry, agriculture, transport (including shipping), households in urban and rural settings, and atmospheric deposition (Figure 2). In the EU, the main point source of water pollution is the discharge of untreated or inadequately treated urban and/or industrial waste water. Point sources are the main source of oxygen-consuming substances, hazardous chemicals and nutrients. The main diffuse source of water pollution is agriculture, which is responsible for the release of pollutants such as nutrients, pesticides, and faecal microbes (EEA, 2018a). Diffuse pollution from agriculture and forestry enters water bodies through the infiltration of the soil or runoff from land. To ensure that urban waste water does not harm the environment, in the EU it is typically collected from households and some industries and treated in urban waste water treatment plants (WWTPs). Some agglomerations may, for technical and/or economic reasons, have a partial collecting (or even treatment) system. Under the UWWTD, such systems are called individual or other adequate systems (IAS), which either collect waste water onsite (to be transported to a WWTP) or treat it locally before it is discharged. Figure 2: Sources and pathways. Fuchs et al. (2010). (MWWTP=WWTP in this text). In EU countries, use is made both of collecting systems designed to collect both urban waste water and rainwater (combined sewers) and of separate systems that collect waste water and storm water separately. Urban runoff can enter a combined collecting system where it mixes with urban waste water, and can subsequently be treated at a WWTP, before the treated effluent is discharged directly into the receiving water bodies. After heavy rainfall, these systems typically do not convey the entire flow of runoff and waste water to the WWTP. For these instances, there are built-in overflows that allow the system to discharge the untreated, diluted rain/urban waste water mix into water bodies. Urban runoff can contain a wide variety of pollutants, including metals, urban pesticides and abrasions from tyres. Water bodies in the EU are seriously affected by pollution from diffuse and point sources (Figure 3). According to Member State reporting, only 40% of surface water (i.e. water in rivers, lakes and coastal water bodies) is in good ecological status, while only 38% is in good chemical status. Across the EU, 38% of surface water bodies fall short of good ecological status because of diffuse sources of pollution, of which agriculture is reported to be the most significant one. Atmospheric deposition affects 38% of surface water bodies, with mercury being the main pollutant responsible for failure to achieve good chemical status. Point sources affect 18% of surface water bodies. Urban waste water is the most significant of these, directly followed by emissions from industry (EEA, 2018b).

Figure 3 Proportion of water bodies affected by a) main pressures, b) detailed point source, c) diffuse source and d) hydromorphological pressures. EEA (2018b). Agriculture and livestock account for roughly a third of the organic matter (BOD) loads entering EU water bodies: other sources include industry and forestry (Figure 4). The relative significance of the sources varies considerably across Member States: in those countries where urban waste water is still not dealt with adequately, it plays a relatively more significant role than in those that treat it appropriately. As regards nutrients, fertiliser use accounts for about one third to a half of all nitrogen (N) loads entering European regional seas (Figure 5). Nitrogen loads via waste water are the main sources of nitrogen only for the Greater North Sea and the Celtic Seas, whereas in all other cases other sources predominate. For phosphorus (P) the situation is slightly different from N. Waste water is still one of the main sources, and agriculture is comparatively less significant (see Pistocchi et al., 2019). UWWTD as intervention Adopted in 1991, the UWWTD has as the objective protecting the environment from the adverse effects of urban waste water discharges (Art. 1). Its intervention logic is shown in Figure 6. Back in 2002, the Court of Justice of the European Union ruled that the objective does not only refer to the protection of the aquatic environment but also includes the wider environment and human health (Case C-280/02 ). The Directive addresses Member States and sets out EU-wide rules for the establishment of waste water infrastructure, minimum treatment standards and requirements on monitoring, reporting and information provision. The main actions required by Member States are the collection of waste water in urban agglomerations of at least 2 000 population equivalents (p.e.) (Art. 3) and the application of secondary treatment to reduce oxygen consuming substances which are measured by biochemical oxygen demand (BOD) and chemical oxygen demand (COD) parameters (Art. 4). Member States are also required to designate sensitive areas (Art. 5). These areas can be designated according to three criteria: (a) areas that are eutrophic or at risk of becoming eutrophic; (b) surface waters that serve as catchment areas for drinking water; and, (c) areas where further treatment is needed to ensure that the objectives of other Directives are met. When discharging treated waste water in these sensitive areas or their catchments, Member States are required to apply more stringent treatment in agglomerations above 10 000 p.e. If these sensitive areas are designated under criterion (a), Member States are expected to reduce N and/or P loads (Art. 5). The reduction levels for sensitive areas designated under criteria (b) and (c) are to be derived from other water legislation, e.g. the Drinking Water Directive or the Water Framework Directive. Member States can also designate less sensitive areas in marine water bodies. They are required to review the identification of sensitive areas at least once every four years. Member States are also required to ensure that WWTPs are properly designed, constructed, operated and maintained, so as to ensure that they perform properly. They must also be able to operate under all normal weather conditions, taking seasonal loads into account (Art. 10). Furthermore, the UWWTD states that certain industrial food processing sectors producing biodegradable industrial waste water, similar in composition to urban waste water, are to be dealt with under this Directive (Art. 13). The Directive also contains an obligation to establish measures to limit pollution from storm water overflows under extreme situations, such as unusually heavy rain (Art. 3(2)). It further requires the monitoring of sewage sludge disposal (Art. 14). In terms of reporting and information provision, the UWWTD requires Member States to submit information stemming from the monitoring provisions under Art. 15 within six months upon request. The Commission subsequently publishes an implementation report based on this data (Art. 17). Member States also need to inform the public of how they deal with urban waste water (Art. 16). The UWWTD sets out clear deadlines on the implementation of the different provisions. For Member States which joined after 2004, these deadlines were negotiated as part of the Accession Treaties (see implementation deadlines). Based on the data submitted by Member States, the Commission publishes an implementation report at two-yearly intervals, which covers one year of results. The 9th implementation report , published in 2017, is based on 2014 data from Member States. Publication of the 10th report, based on 2016 data, is scheduled for early 2020. The UWWTD in the context of other EU (water) legislation EU water legislation has been in place since the 1970s, when legislation such as the original Bathing Water and the Drinking Water Directive was adopted. In the 1990s, pollution-focused Directives such as the UWWTD and the Nitrates Directive (dealing with water pollution from nitrates used for agricultural purposes) were adopted. Since then, EU water policy has been further expanded through the adoption of the Water Framework Directive (WFD) and its daughter Directives (the Groundwater Directive (GWD) and the Environment Quality Standards Directive (EQSD)). The WFD establishes a holistic approach to water management and environmental protection, with a focus on river basin planning. It states that Member States need to protect good ecological and chemical status in their water bodies (or achieve such status), and preserve their water bodies against deterioration. Complementing the WFD, the Marine Strategy Framework Directive (MSFD) establishes a common approach and objectives to protect the marine environment against damaging human activities. Water policy has also been further developed through the revision of the Bathing Water Directive (BWD) and the recent Drinking Water Directive recast proposal (DWD) (2018). This EU water acquis was developed to deliver a comprehensive approach to the various sources of known water pollutants that were of concern at the time (Figure 7). Figure 7 EU water legislation The UWWTD plays an important role in the EU water acquis and lays down the minimum requirements for urban waste water collection and treatment. Annex I to the UWWTD states that ‘more stringent requirements …shall be applied where required to ensure that the receiving waters satisfy any other relevant Directives’. It further specifies that Member States need to designate sensitive areas that are subject to eutrophication or at risk thereof, that are drinking water catchment areas, or that are ‘areas where further treatment …is necessary to fulfil Council Directives’ (Annex II). Furthermore, the UWWTD is a basic measure under the WFD and MSFD. Both these framework directives state that if measures taken under the UWWTD are not sufficient to achieve the objectives of the WFD and the MSFD, Member States need to take other appropriate measures, such as adapting treatment levels or the way in which they deal with storm water overflows. The implementation of the UWWTD is also crucial to achieving the BWD’s and DWD’s objectives, as inadequately treated waste water discharges can pollute bathing water sites and drinking water sources. The UWWTD is also important for the implementation of the Sewage Sludge Directive (SSD), which deals with the reuse of sludge for agricultural purposes. As the SSD uses one of the outputs of the UWWTD, it is very dependent on this output being appropriate for its own purposes.

More recently, the Commission adopted the European strategy for plastics in a circular economy (‘Plastics Strategy’) and the Strategic approach to pharmaceuticals in the environment (‘PIE Strategic Approach’). These strategies highlight the potential role of the UWWTD (and waste water treatment more generally) as a means to tackle end-of-pipe contaminants of emerging concern, such as microplastics and pharmaceuticals. Furthermore, the EU has taken action on a number of other issues relating to urban waste water discharges, in the context of its strategy to boost a circular economy . The need for sufficient water quantities is reflected in the recently adopted EU Energy Strategy and Energy Union . 2.2.Baseline and point of comparison At the time when the UWWTD was drawn up and adopted, there was no impact assessment requirement. For this Evaluation, it was therefore necessary to develop a retrospective baseline for 1990, based on Eurostat and OECD data (Annex 4, Baseline by Member State. Following assessment, this is considered to be the best available data for the 1990 baseline. The 9th implementation report (2014 data) can be used to demonstrate the achievements resulting from the adoption and implementation of the UWWTD. When the Directive was adopted, the levels and extent of Member States’ waste water infrastructure varied widely; for example, some capital cities were not yet connected to treatment facilities. Levels of population with treatment varied between 11% and 94% (Figure 8). Figure 8 Population with treatment, blue = 1990s, orange = 2014 In the early 1990s, EU-level estimates for the loads of BOD in discharged urban waste water were about 3.7 million tonnes/year, N loads from urban waste water releases were about 1.0 million tonnes/year and P stood at about 0.2 million tonnes/year. These releases of pollution into EU water bodies were causing intolerable conditions and thus reducing the amenity value of rivers, lakes, estuaries and coasts. This was the background against which the UWWTD was adopted. Other EU legislation on water quality sets other standards for certain parameters, depending on the protection goals (Table 1), which may differ from those of the UWWTD. Assessing the UWWTD’s impact on the extent to which the protection goals of other directives are met provides a measure of the Directive’s success. Protection goal Parameter Aquatic Ecosystems (WFD) Drinking Water (DWD) Bathing Waters (BWD) N X X P X BOD X Microbiological X X X Chemicals X X In terms of the water quality situation in the early 1990s, BOD concentrations in rivers averaged almost 4 mg/l across the Member States, N concentrations were 2.5 mg/l or more, and P concentrations in rivers stood at about 0.12 mg/l, according to monitoring data provided by Member States (EEA, 2019a). As regards bathing water sites, only about 52% of inland waters and about 80% of coastal bathing waters met the required standards in the 1990s (EEA, 2015). Since data from the 10th reporting (reported data for 2016) were not available during the Evaluation’s analysis stage, the analysis is based on 2014 data. The state of play section, however, reflects some data from 2016. Baseline population figures connected to treatment (Figure 8) and levels of BOD, N and P have provided the basis for an assessment of whether the Directive’s general objectives (load reductions and improving water quality in relation to waste water) have been achieved since the UWWTD’s adoption. Thus, indicators for success are reduction of loads and achievements in terms of protecting or improving water quality. Furthermore, two hypothetical ‘What if no Directive’ (WIND) scenarios were developed. The WIND scenarios represent the state in which waste water treatment in the EU would hypothetically have remained had there been no UWWTD. This involves making some assumptions about how much progress the Member States would have made with national approaches to collecting and treating waste water if there had been no Directive. For these scenarios, it is assumed that some Member States would have reached similar levels of collection and treatment as under the UWWTD, whereas others would be in an intermediate situation between the 1990s baseline and current implementation levels, depending on their specific capacity to plan, invest in, and manage WWTPs. Analysis considers the following four scenarios: 1991 baseline, 2014 reported progress and the two WIND scenarios. 3.State of play According to the forthcoming 10th implementation report, based on 2016 data, there are about 23 600 ‘agglomerations’ in the EU as defined under the UWWTD for 2 000 p.e. and above. These agglomerations generated a total load of 612 million p.e., mostly corresponding to urban waste water and runoff, but also to some from industrial sources. To assess compliance with the Directive, the assessment currently focuses on meeting the requirements of three Articles (Articles 3-5 inclusive) at agglomeration level. Compliance with Articles 4 and 5 (treatment stages) is not possible if compliance with Article 3 (collection system) is not ensured. The same applies to Articles 4 and 5; compliance with Article 5 is not attainable unless Article 4 is implemented. Overall compliance with the UWWTD is now well advanced on average across the EU, with compliance rates for these three articles ranging from 80% to 100%. However, exceptions remain with lower values that need improvement, such as compliance results at EU13 level for Articles 3-5, and for Article 5 at EU28 level (Table 2). Compliance rates Article 3 (collection) Article 4 (secondary treatment) Article 5 (more stringent treatment) EU15 99 % 91 % 91 % EU13 76 % 73 % 66 % EU28 95 % 88 % 86 % Figure 9 displays overall compliance rates by Member State, showing the diversity of compliance rates that is not apparent from the EU average. Clearly, many countries have implemented the Directive well by now, whereas a few others are lagging behind.

Figure 9 Compliance rates per Member States (2016). The situation is slightly different when ‘distance to target’ is considered, which shows good (low) rates in general (10% or below), except for more stringent treatment (Table 3). Distance to target Collection Secondary treatment More stringent treatment EU15 0 % 6 % 5 % EU13 6 % 10 % 15 % EU28 1 % 6 % 7 % The EU compliance rate with Article 3 (collection of waste water) is high, averaging 95.1%. The rates are very high in 21 Member States (95%-100%), while three still have low rates below 70% (RO, BG and SI). Some countries (SK, EL and HU) make extensive use (above 10% of total load) of IAS. Overall, 6.2 million p.e. are not properly collected (1.2% of total EU load) and therefore not properly treated either. 88% of EU waste waters are considered to comply fully with Article 4 (secondary treatment). Twelve Member States have compliance rates between 95% and 100%, while five (IE, MT, RO, BG and SI) still have to make significant efforts to reach compliance, with rates below 70%. Some 46.2 million p.e. do not meet the performance requirements of secondary treatment (9.4% of the total EU collected load that requires this treatment). More stringent treatment (in terms of the rate of compliance with Article 5) is applied to waste water discharged in areas covering more than three quarters of EU territory. Fifteen Member States apply it throughout their territory, whereas the other 13 have identified parts of their national territory as “sensitive”. The compliance rate for more stringent treatment (applicable to agglomerations discharging into “sensitive” areas with more than 10 000 p.e.) is about 76%. Overall, there is still a large difference between Member States, with rates ranging from below 70% to full compliance, and only five countries between 95% and 100%. Significant efforts are still needed in several countries with rates below 70% (BG, CZ, ES, IE, IT, MT, RO and SI). This equals about 17.6 million p.e. not meeting the performance requirements of more stringent treatment (17.3% of the total EU collected load that requires this treatment). The Commission has taken legal action with a view to ensuring correct and timely implementation of the UWWTD. Infringement proceedings have been taken against nearly all EU15 countries, with over 40 CJEU rulings. More than 30 horizontal cases are pending, some of which involve the EU13 countries that joined after 2004. The most frequent issue is Member States’ failure to meet the requirements of Articles 3-5 by the required deadlines. 4.Method The Evaluation, which follows the Better Regulation guidelines, assessed all impacts associated with the Directive quantitatively and/or qualitatively, to the extent possible. The approach used was based on five criteria: effectiveness, efficiency, coherence, relevance and EU-added value. Analysis was based on a list of 27 Evaluation questions (see Annex 4, Overview: mapping of evaluation questions), which were outlined in the Evaluation Roadmap . The roadmap was subject to a feedback mechanism. On the basis of feedback on the roadmap and the Commission’s experience of implementing this Directive, European Court of Auditors (ECA) reports, and previous Commission studies on aspects of the UWWTD, 12 key issues were identified that enabled the assessment of the five evaluation criteria to be substantiated. These key issues were discussed in the early stages of the Evaluation with a number of major stakeholders and validated in this process. The findings on the key issues are included in the report where most appropriate (see Annex 4, Overview: mapping of Evaluation questions). To avoid losing any valuable information, cross-referencing is used throughout the document. An external contractor supported the Evaluation by developing key issue studies and an Evaluative support study. Unless otherwise stated, all data used in this report come from these studies. Modelling results are taken from the Joint Research Centre’s Science for Policy report (see Annex 3, JRC modelling) (Figure 10). 4.1.Literature review An extensive literature review was conducted, encompassing scientific studies, ECA reports, ongoing and past Commission studies (e.g. Blue2 (EC, 2018a), the joint OECD study on investment needs in the EU water sector), the work and databases of the European Environment Agency (EEA), the JRC’s work, and national studies where available. These findings were triangulated with results from modelling approaches and stakeholder consultations. The EEA and water quality information The EEA provides extensive information and analysis on water and the marine environment, covering topics such as industrial emissions into water, chemicals in water, and bathing water. The Agency also provides access to vast amounts of information through its data and map viewers. The data viewers compile information provided by Member States reporting under the various water directives and information provided voluntarily under agreements among countries. The EEA’s analyses and data portals provide Europe-wide overviews of water quality development over time, plus analysis on pollution sources and underlying factors for improvement. OECD study on investment needs in the EU water sector In 2017 DG ENV launched a cooperation project with the OECD to assess investment needs associated with UWWTD, DWD and the Floods Directive in the EU Member States. This analysis provides a comparative overview of investment needs and assesses possible financing sources (i.e. tariffs, taxes, transfers). Following the analysis, joint OECD-Commission workshops were held in 9 Member States. These workshops hosted discussions among all relevant stakeholders in efforts to find solutions for the future. The analysis and the workshops have provided a wealth of information on financial needs associated with the UWWTD and on practical implementation problems. The cooperation project is due to finish in February 2020. Some preliminary findings have already fed into the Evaluation.

4.2.Stakeholder consultation The Commission set out a joint Consultation strategy for this Evaluation and the Water Fitness Check (Water FC) (EC, 2018b). The main stakeholders identified were consulted by different means (see Annex 2, Stakeholder consultation). Public consultation A 14-week online public consultation was held between July and October 2018. Comprising one general section and another specifically for experts, it was available in all 23 official EU languages. There were 608 replies, half of them from citizens. The two largest stakeholder groups responding were associations and WWTP operators. Replies came from 24 of the 28 Member States, with stakeholders in Germany and Spain accounting for the lion’s share. Targeted consultation In March 2018 individual interviews were held with nine stakeholders representing major stakeholder groups, to discuss and check the key issues. Four expert workshops were held. They focused on selected topics identified as particularly relevant and difficult to assess through a review of the literature: ·Pollutants of emerging concern ·Storm water overflows (SWOs) and IAS ·Costs and benefits of the UWWTD ·Technical modelling workshop on the combined sewer overflow (CSO) model. These workshops fed into the Evaluation as they served to identify further information, to check the correctness and relevance of the identified evidence, and to validate preliminary findings. On 16 November 2018, a stakeholder conference was held on the premises of the Committee of the Regions to share the preliminary findings of the support study and some initial results from the public consultation. The conference validated the findings and some further information emerged which was incorporated during the finalisation of the Evaluation. Participants in all stakeholder activities included Member State authorities, other institutions (e.g. World Bank, OECD), NGOs, industry associations and the scientific community. As part of the OECD study on investment needs in the water sector, nine Member State visits were organised to discuss findings on investment needs and future financing options. In addition to the technical workshops, the Member States were consulted in writing on some specific aspects of the modelling (management measures in place for storm water overflows (SWO) and information on IAS) for which limited data were available. Member States also received the preliminary results of the cost and benefit assessments. They were asked to provide feedback on findings for their country or to add to the identified information. 4.3.Modelling Science for policy – the effects of the UWWTD The JRC’s modelling of the effects of the UWWTD for this Evaluation, described in the Science for Policy report ‘Water quality in Europe: effects of the Urban Waste Water Treatment Directive’, enabled the reduction of pollutant loads (BOD, N and P) in treated waste water over time to be assessed. The modelling results show the effects of the UWWTD only and filter out the impact of other legislation. The modelling also estimated subsequent improvements in water quality associated with the UWWTD’s effectiveness, against different water quality standards based on various other water directives that benefit from the UWWTD’s existence (e.g. WFD, DWD, BWD). The JRC used the Geospatial Regression Equation for European Nutrient losses model (GREEN+ model), which was developed to estimate annual N and P loads and performed source apportionment at pan-European level. The JRC extended the model to include BOD, chemicals and coliform bacteria. This model includes both point sources (WWTPs, industries, and paved areas) and diffuse sources (fertilisers, atmospheric deposition, and scattered dwellings). A 1990 baseline for waste water treatment for each Member State was established and used as a point of comparison the present levels of waste water treatment based on data from the 9th implementation report. The following scenarios were also modelled: full implementation, impact of individual and other appropriate systems, impact of CSO. There were also two scenarios looking at what would have happened without the Directive (‘What-if-no-Directive’ (WIND)).

To establish the WIND scenarios, two different sets of weights were used (WIND1 and WIND2, see Annex 3, WIND). These scenarios are quantified in a simplified way as a weighted average of the two scenarios (baseline and pre-directive), as is usual in statistical data fusion. Details of the modelling exercise are set out in Annex 3, Science for Policy, and in the Science for Policy report on the subject. Costs-benefit assessment Benefit modelling: At the time of the Evaluation, there was no single established methodology to assess the benefits associated with the UWWTD and waste water treatment in general. However, stakeholder consultations and research findings show that urban waste water treatment helps provide many environmental, social and economic benefits. For both, costs and benefits, the estimates developed for this study should not be interpreted as economic reality. Rather, they provide indicative ranges of the order of magnitude of the costs and benefits associated with the UWWTD. Further efforts should be made in future to establish a thorough benefit methodology. Only three benefits were quantified and monetised at EU level: benefits of nitrogen reduction as a proxy for water quality and health, the reduction of micro-biological pollutants as a proxy for bathing water quality, and the cost savings of moving from individual to central collection systems. It was not possible to monetise the reduction of BOD, COD or P or the removal of non-targeted chemicals across all Member States. For the first two benefits, a damage cost approach based on a benefits transfer from willingness to pay studies was used. For the move to more collection through centralised collection systems, the costs saved by not having to maintain individual or other appropriate systems were assessed. To assess the costs associated with implementing the Directive, two separate and established cost functions were used, one for collection systems and one for the different treatment levels, derived from the FEASIBLE model. The cost functions were adjusted to Member States’ price levels in 2014. Costs were annualised with a discount rate of 4%, as suggested in the Better Regulation guidelines. A lifetime of 25 years is assumed for WWTPs and a lifetime of 50 years for collection systems. Costs were broken down into capital (CAPEX) and operation and maintenance (OPEX) costs. Cost correction factors were used to ensure that only costs and benefits attributable to the UWWTD and its influence on how Member States deal with urban waste were taken into account. Results were produced for the 2014 implementation levels and for full implementation. In response to the written consultation, Member States that have a national cost assessment and that responded to the consultation reported that the overall order of magnitude is correct, but also stressed that cost assessments are challenging even at national level. For details of the methodology, see Annex 3, costs and benefits and the key issue report. 4.4.Limitations and robustness of findings Water quality is very complex, as it can be characterised in different ways and is subject to many external factors (e.g. geology, catchment type). There are many sources of water pollution. Waste water discharges are only one kind, along with pollution from industry, agriculture, and atmospheric deposition. The impact of pollutant releases varies according to the type of water body receiving the pollution, but also depends on the ecosystems affected and the use to which the water may be put downstream (bathing sites, drinking water production, etc.) This made it difficult to assess all environmental and health benefits in quantitative and monetary terms. There is a lack of published sound methodologies linking improvement in water quality to quantitative effects on health and ecosystems. Although treating waste water brings health benefits (see benefits), these are indirect (improvement of raw water used for drinking water production, improvement of water quality for bathers). Moreover, they can hardly be attributed solely to the UWWTD, given the existence of other related legislation (BWD and DWD). It was also not possible to assess benefits relates to tourism and the impact on the economy. Although the Directive has been in place for 28 years, long enough for a good evidence base to have been gathered, there is a lack of EU-wide comparable data on certain topics. Comparably sound data were found on connection rates and treatment levels. Data of limited comparability were found on IAS and SWOs, a shortcoming addressed by conducting an additional written consultation of the Member States. Extrapolations and/or assumptions, based on expert judgement, were used to complement the available evidence base. It was necessary to make a few different assumptions about the impact of the Directive compared to the baseline to model water quality and assess costs and benefits. Such differences are not thought to alter the conclusions drawn from the assessment. Any assumptions and identified uncertainties are highlighted in this document and its annexes, and in the Science for Policy report, the Evaluative support study and the related key issue studies. Since all information and results from modelling exercises were triangulated against each other as far as possible, the overall robustness of the findings can be confirmed. 5.Analysis 5.1.Effectiveness Evaluation question: To what extent has the UWWTD reached its objectives and what factors impact on its effectiveness? Evidence shows that, as expected, the Directive has led to reductions of BOD, N and P loads released from urban waste water point sources into the environment. Modelling results show that, between the adoption of the Directive and 2014, BOD, N and P loads in treated waste water fell by 61%, 32% and 44%, respectively. Further reductions can be expected once the Directive is fully implemented. The reductions achieved so far, especially of BOD and P content in water bodies, have had the expected positive effects on the aquatic environment. Rivers, seas, lakes, coastal zones and designated bathing sites have seen substantial improvement and a big part of this can be linked to the UWWTD. Furthermore, although the treatment required by the UWWTD does not directly target chemicals (other than N and P), including contaminants of emerging concern, it has substantial impact on their reduction as well. Nevertheless, point source pollution from untreated or inadequately treated urban waste water is still one of the main reasons for why EU waters fail to achieve good ecological status. According to data reported under the 2nd round of river basin management plans (RBMPs), urban waste water is a significant pressure on 12% of surface water bodies, leading them to fail to achieve good ecological status under the WFD. The main factors that impact the effectiveness of the UWWTD are related to both the text of the UWWTD itself and to a lack of implementation in several Member States. These factors will be discussed in more detail below. 1.Non-compliant agglomerations produce a high proportion of avoidable loads and put pressure on EU water bodies. In the last decade, UWWTD implementation levels have increased across the EU on average, but some Member States took a long time to become compliant and some are still not fully compliant. The initial deadlines set in the Directive and those negotiated in Accession Treaties seem to have been overambitious. Clearly, implementing the Directive is challenging for some Member States in terms of required funding, as well as institutional and administrative capacity. However, evidence shows that some Member States have managed to implement the Directive in a rather short time (i.e. EE and LT). To advance implementation, the Commission provides support through compliance promotion activities and drives it through infringement procedures, whenever appropriate. It also supports it through funding, as implementation of the UWWTD requires substantial and continuous investments in infrastructure. Member States use a mix of public budget, taxes and water tariffs to finance implementation. Many relied, and some still heavily rely, on EU funding to build up the initial infrastructure. Only a few Member States have moved towards full cost recovery through water tariffs. Most Member States use water tariffs to have households and some industries partly pay for (waste) water services, and so the polluter pays principle is being respected to some extent. According to the analysis, the general affordability of water services is not at risk in any country, though in some countries, such as Romania and Bulgaria, the burden borne by lower income households is slightly higher than in other Member States. A number of financing and management problems were noted in some Member States, e.g. lack of effective use of funding and issues with national procurement rules. The analysis also considered whether unclear terminology reduced the effectiveness of the UWWTD. Overall, the UWWTD is effective largely due to its clarity – including as regards implementation deadlines - and its enforceability. Discussions with stakeholders and other research revealed only a few terms and obligations that need further clarification. 2.The UWWTD provisions give Member States the flexibility to use IAS if the cost of a collection system would be disproportionate and as long as the individual system used achieves the same level of environmental protection as a collection system would. IAS can be a way of adapting to geographical circumstances. The UWWTD is not clear on how costs and benefits need to be assessed in order to ascertain whether IAS could be used, what ‘sufficiently concentrated’ means in the context of agglomerations or how Member States need to monitor the effectiveness of IAS use. Some Member States report high IAS use, also in larger agglomerations where a collecting system is in place. Badly designed, monitored and maintained IAS can lead to ineffectively collected waste water and can cause releases of untreated waste water affecting the environment. This is an issue of implementation, as well as of clear provisions under the UWWTD itself. 3.The UWWTD covers agglomerations below 2 000 p.e. only to a limited extent. Information from the 2nd round of RBMPs shows that small agglomerations and non-connected dwellings can be a factor in not reaching good status under the WFD. The impact of small agglomerations and non-connected dwellings and their discharges depends on local conditions such as the discharge point and the type and size of the receiving water body. It is expected that in many small agglomerations substantial use of IAS is made. 4.The UWWTD addresses SWOs only to a limited extent. Case-law has helped clarify the UWWTD’s only reference to this (in a footnote), but the Court pointed out a need to develop related guidance. SWOs are mostly a problem at local level, but EEA and JRC findings show that they can have a significant environmental impact. This pollution source is becoming more relevant with increasingly heavy rainfall and higher levels of UWWTD implementation. Related to SWOs is urban runoff, a component of combined sewage. The pressure created by runoff is partly covered by the UWWTD (when the runoff enters the combined sewer system) and partly by the WFD (when the runoff discharges directly to receiving waters through separate storm sewers, where Member States identify it as a pressure to meeting environmental objectives). With increasingly heavy rainfall induced by climate change and increasing imperviousness of urban surfaces, urban runoff may have an increasingly negative impact on water quality. 5.Although the UWWTD requires the designation of sensitive areas under criterion A, for those areas that are eutrophic or at risk of eutrophication, it is not very specific on how to assess eutrophication. The Court set out four criteria to assess eutrophication. Evidence shows that neighbouring Member States do not always apply the concept in the same way, however. This may lead to less improvement than what can potentially be achieved. Also designation under criteria B and C is not clear. Note that waste water pollution needs to be seen in the context of pollution from other sources: in a number of cases other diffuse and point sources, such as agriculture and industry, are the dominant pollution sources. The relative significance of these sources is expected to increase under full UWWTD implementation. The effectiveness of the UWWTD’s provisions on monitoring, reporting and disseminating information has also been assessed, and is discussed below: 1.Overall, the monitoring requirements are effective in supporting the Commission’s compliance assessments and the data provided under these requirements have been used for infringement cases. To address local conditions, a number of Member States have set stricter threshold levels for BOD, N and P, demonstrating that it is possible to achieve more than what is expected under the UWWTD. Monitoring provides only a partial picture of what is entering the environment via WWTPs, as few samples are required and monitoring is only required for a limited number of parameters. Further evidence is needed to understand the impact of this. Monitoring provisions are not directly required to adapt to changing external factors or new technologies. The Directive does not contain (clear) monitoring requirements for SWOs and IAS. 2.The reported data, which are based on the monitoring results, were essential to ensuring effective enforcement. However, the process of assessing reported data is still time-consuming and the information is not made available quickly enough. Moreover, the legal text as well as some of the parameters are not yet fully aligned with other related (more recent) legislation. Furthermore, Member States do not always provide all information in a comparable way, such as information on investments, nor do they always comply with agreed formats and data management processes, e.g. those set by the INSPIRE Directive . 3.The Directive requires that Member States provide situation reports as information to the public. This has led to diverse practices across the EU and it is not clear whether the information that the public is interested in is made available to them. Practices in Member States are very diverse and there is significant potential for improvement. At EU level, the Structured Information and Implementation Framework (SIIF) is a step forward in modernising the ways in which information is provided. Generally, the public is interested in information on waste water, especially on aspects that affect their daily lives, such as where treated waste water is discharged and associated costs. People are also interested in information on what they pay for in terms of water services. The Directive does not ensure that this kind of information is made available. The effectiveness analysis considers how successful the UWWTD has been in achieving or progressing towards its objectives. Where the objectives have not been achieved, the assessment considers the extent to which progress has fallen short. The underlying reasons are discussed in the section on factors influencing the UWWTD’s effectiveness. Achievement of the Directive’s objectives As regards pollutant loads in treated waste water, modelling shows that the UWWTD has had a significant impact. At EU level, organic matter in treated waste water, assessed based on BOD levels, has decreased from 3.7 million tonnes per year before adoption of the UWWTD to 1.4 million tonnes per year, from 1 to 0.7 million tonnes for N and from 0.2 to 0.1 million tonnes for P ( Table 4). Further reductions are expected once the UWWTD is fully implemented. This decline in BOD and phosphorus concentrations due to the enforcement of the UWWTD and investment in urban waste water treatment has also been noted in the recent state of the environment publication by the European Environment Agency (EEA, 2019c). Modelled loads from urban waste water sources (tonnes/year) Parameters 1990 2014 Reduction 1990 to 2014 Residual load under full implementation BOD 3,703,875 1,451,561 61% 887,022 N 1,007,511 689,626 32% 572,386 P 210,118 118,069 44% 102,123

Stakeholders that replied to the public consultation generally agreed that the UWWTD has been either very effective or somewhat effective (46% and 42%, n =345) in protecting the environment, with only 1% judging that the Directive was very ineffective and 4% judging that it was neither effective nor ineffective. Biochemical oxygen demand The achieved reduction in BOD loads is substantial. In most Member States, loads have halved compared to levels seen in the 1990s (Figure 11). Figure 12 BOD in selected European monitoring stations. EEA (2019a). Evidence from selected European monitoring stations shows that BOD levels have indeed reduced: since 1992, the presence of oxygen-demanding substances (measured based on BOD) have substantially decreased. The decrease is about 2.7% per year (0.08 mg O2/l), with a significant decrease of 64% at monitored river sites (Figure 12) (EEA, 2019a). Models show a clear reduction of BOD loads in water bodies, with about 4% of the river network moving up to ‘good’ status and additional further improvement expected under full compliance (Figure 13). However, the EU average hides the fact that a number of Member States still have to make significant progress (notably RO, IT, ES, BG). Based on WIND results, it can be assumed that some Member States would have 10% less of their river network in good or high status if the Directive was not in place (see Annex 4, WIND results). These findings are confirmed by stakeholder replies to the public consultation: according to 52% and 29% of respondents, respectively, the Directive has been either very effective or somewhat effective in reducing BOD. Only 1% of respondents said that the Directive was very ineffective and 5% replied that it was neither effective nor ineffective (n=343). Nitrogen A reduction in N released through treated waste water is also clearly visible (Figure 14), and was achieved due to the implementation of Article 5. The EEA’s assessment of data from selected European river monitoring stations shows that there was steady decrease in nitrate concentrations since 1992, and links this to improved waste water treatment (and the UWWTD). On average, the nitrate concentration has decreased by 0.02 milligrams/l of nitrogen (0.8%) per year between 1992 and 2015 (Figure 15) (EEA, 2019a) Figure 15 Nitrate in selected European monitoring stations. EEA (2019a). As shown in the state of play section and in Figure 14, some Member States still need to make substantial efforts to increase treatment for N. In spite of this, modelling suggests that, under current implementation levels, the UWWTD has improved the status of about 4% of the river network from below ‘good’ to ‘good’ or ‘high’. Under full compliance, another 0.7% of the river network could achieve ‘good’ or ‘high’ status (Figure 16). Estimates of what would have happened without the UWWTD show that some Member States would not have seen any improvement in about 20% of their river network (Annex 4, WIND results).

Figure 16 EU-28 river network conditions regarding N quality standards under different scenarios Annex II of the UWWTD refers to the requirement for Member States to ensure that surface waters intended for the abstraction of drinking water do not contain nitrate concentrations above those set out in the DWD . Note that improvements appear smaller when considering higher concentration thresholds, such as those of the DWD (Figure 17). Figure 17 EU-28 river network with N limits below those set out in the DWD (11,3 mg/l) and precautionary limits applicable to children (6 mg/l). The most significant source of N is diffuse pollution from agriculture (see the section on contextualisation). Additionally, N has a potentially long residence time in groundwater, which means that the effects of load reduction measures may only be visible after decades in the downstream surface receiving waters (Grizetti et al, 2017). The public consultation results regarding the UWWTD’s effectiveness to reduce N show that stakeholders are slightly less positive on N compared to BOD, with only 38% judging that the UWWTD was very effective and 36% that it was somewhat effective. Only 1% of respondents considered the UWWTD to be very ineffective, and 9% judged that it was neither effective nor ineffective (n=344). Phosphorus Modelling shows that there has been a significant reduction in P released through treated waste water, and that this was achieved through compliance with Article 5 (Figure 18). Monitoring data from rivers and lakes across the EU support this finding and show that concentrations of orthophosphate in rivers have more than halved between 1992 and 2015 (Figure 19). The EEA links this to the implementation of the UWWTD and improvements in the EU’s regulation of P in detergents. According to modelling results, the status of about 10% of the EU river network improved from below ‘good’, to ‘good’ or ‘high’ thanks to UWWTD implementation. An additional improvement of about 1% can be expected with full implementation (Figure 20). Without the Directive, up to 50% of the river network in some Member States would be below ‘good’ status (see Annex 4, WIND results). However, when considering other sources of P in EU water bodies, urban waste water remains one of the main pressures. In the public consultation, 37% of stakeholders held that the UWWTD was very effective in reducing P and 36% held that it was somewhat effective (n=343). Only 1% held that it was very ineffective and 10% considered it neither effective nor ineffective. Impact of the UWWTD on bathing waters and on chemical concentrations in treated waste water The UWWTD’s effectiveness can also be assessed using bathing water quality standards for microbiological pollution. This is related to point (c) of Annex III of the UWWTD, which requires more stringent treatment when this is necessary for the attainment of objectives under other directives – in the case of bathing waters, the BWD. Some Member States have categorised areas as sensitive due to the presence of bathing water sites, and apply disinfection as the more stringent treatment required (see coherence). Removal efficiencies for coliforms of primary and secondary treatment are on average 95%. Results show that the UWWTD has had a substantial effect on improving bathing water sites in the EU (Figure 21 and Figure 22), in accordance with the BWD’s thresholds for inland and coastal bathing sites. Without the impact of the UWWTD, it is estimated that, on average in the EU, more than 25% of improvements would not have been achieved.

In 2017, 96% of the EU’s designated bathing sites reached the minimum quality requirements of the BWD, with 85% rated ‘excellent’. This compares to 80% compliance for coastal waters and 52% for inland waters in the 1990s . According to the EEA, in the past the release of untreated waste water into the environment was a primary source of pollution. Bathing water quality improved partly due to heavy investment in waste water collection and treatment (EEA, 2018c, EEA, 2019c). Furthermore, through secondary and more stringent treatment, some chemicals (other than N and P), including pharmaceuticals, are partially or entirely removed depending on their behaviour in the process (Figure 23) , whereas other chemicals are effectively not removed from the influent to the WWTP. A preliminary modelling of chemical removal during the different waste water treatment stages shows that, before adoption of the Directive: ·around 30% of the length of the EU river network was below concentration thresholds that may be assumed to correspond to good conditions in terms of chemical pollution, and ·more than 50% was below a threshold assumed to represent good conditions. In a scenario where the Directive is fully implemented, these increase to more than 50% and 80%, respectively. Although chemicals have different behaviours and outcomes in WWTPs, this pattern can be observed for most. Thus, the UWWTD has also been effective in removing non-target chemicals. For some chemicals, however, being removed through treatment means that they are transferred to and concentrated in the sludge (for details, see Pistocchi et al, 2019). Factors influencing the effectiveness of the UWWTD The Evaluation results have shown that, in general, the UWWTD is achieving its objectives to help protect the quality of EU water bodies. By doing so it also supports the attainment of the objectives of other EU legislation related to water. Member State reporting under the WFD, however, shows that urban waste water still results in 12% of surface water bodies failing to achieve good ecological status. In addition, modelling shows that full compliance with the UWWTD could help avoid around 490 000 t/year of BOD loads being discharged from non-compliant agglomerations. Additionally, 110 000 t/year of BOD loads from IAS and 210 000 t/year from SWOs could also be avoided. Though not directly covered by the Directive, the requirement to ensure the same treatment levels for loads from small agglomerations and non-connected dwellings would lead to about 230 000 t/year less BOD being discharged. Lastly, 690,000 t/year BOD could be avoided by fully dealing with urban runoff (Figure 24). Thus, although the Directive is generally effective in reducing loads and improving water quality, a number of factors reduce its effectiveness. These factors either (i) relate to late or incomplete implementation, (ii) stem directly from the Directive’s text, or (iii) arise from issues that are not (directly) in the scope of the Directive. Late implementation: reasons behind late or incomplete compliance One of the factors that negatively influence the UWWTD’s effectiveness in terms of reducing loads and protecting water quality is that several Member States have not yet fully implemented the Directive. According to Figure 24, a high proportion of remaining loads comes from non-compliant agglomerations. This is in line with the findings discussed in the state of play section. In the early 1990s, the levels of infrastructure in place for waste water collection and treatment varied across the EU-15. When the UWWTD entered into force, it set out standard deadlines by which all Member States had to meet its requirements. Even though over time many Member States reached good implementation levels, some EU-15 and EU-13 Member States still have not fully complied with requirements. The high number of infringement cases that were opened against Member States, especially based on Articles 3-5, demonstrates the scale of the issue. In total, there were 29 infringement cases related to Articles 3-5 with a final ruling at the time of the Evaluation. Overall, it seems that the deadlines initially accepted by the 12 countries that were EU Member States when the UWWTD was adopted and were later included in the successive Accession Treaties were overambitious for several Member States. However, some Member States that joined the EU after 2004 managed to increase compliance very quickly, e.g. EE increased compliance with Article 3 from 30% in 2010 to 94% in 2014, thanks to good use of funding and strong political will. A major underlying factor for delays is financing and this is discussed separately in the section on financing UWWTD implementation.

Challenges for UWWTD implementation in Italy Italy has a complex institutional set-up for implementing the UWWTD. Although administrative arrangements and relationships are set in the national legislation, communication and coordination between national and regional or local authorities can be slow. This is crucial, because the Italian regions are responsible for monitoring, managing and protecting water bodies, as well as planning infrastructure and enforcing law. The authorities responsible for water supply and sanitation services in Italy are the AATOs (‘Autorità di Ambito Territoriale Ottimale’), which were specifically created to manage integrated water services. AATOs plan the investments necessary and then delegate the management of the integrated water services to a joint-stock company. In principle, the public authorities maintain ownership of the infrastructure, while the integrated water services may be handed over to either publicly-owned operators or privately-owned operators under contract. In some Member States, there also seems to be a lack of institutional ability and administrative and technical capacity to implement correctly the Directive, as well as an inability to use funds effectively at local or regional level and to undertake large-scale projects. Furthermore, there are difficulties with planning the implementation of the UWWTD at national, regional and local level across the EU (see box on IT). Problems with public procurement also persist. In addition, some cases indicate that the population forecasting needed to implement the UWWTD correctly (e.g. urbanisation, changing demographics, fluctuations due to tourism) can be difficult and may delay implementation. For instance, in RO and SK there are cases of incorrect sizing of WWTPs, where the infrastructure was undersized relative to the generated load of the agglomeration (ECA, 2015). There are also cases where the efforts and time needed for implementation were underestimated, or where there was a lack of political will to prioritise UWWTD implementation and channel the needed resources into implementation activities. These sorts of situations can lead to a lack of resources at local level, which is where implementation projects are typically run and where infrastructure is managed. A lack of clarity as to responsibilities between governance levels can lead to sub-optimal or delayed implementation as well. There is also evidence that overall governance difficulties impact the implementation, for instance, BE pleaded in Case C-236/99 where BE pleaded that political and administrative difficulties were emerging from the process of institutional reform which it had to carry out to preserve the unity of the State. Due to these difficulties, the implementation of the Directive was delayed. Another difficulty for implementation at all levels can arise if there is opposition from the public. In EL, for instance, the public was opposed to having the necessary infrastructure installed in Eastern Attica, which led to delays in implementing the Directive in this area. In RO, as well as in a few other Member States such as SK and EL, there are cases where people do not want to connect to existing collection systems as they already have individual systems in place and a connection to the collection system is perceived as a very expensive both one-off and recurrent cost. In the public consultation, stakeholders confirmed these findings across all categories, identifying similar barriers — lack of funding and lack of political will — as major issues. Almost half of the respondents held that the Directive has not been implemented effectively (one third of these being citizens), with 37% arguing that it was and 21% stating that they do not know (n=341). When considering only WWTP operators and Member State competent authorities, 42% stated that the UWWTD has been implemented correctly. Stakeholders raised concerns about different levels of ambition across regions, varying levels of industry compliance with minimum standards for effluents, unequal application of IAS requirements and the need to address SWOs more consistently. Overall, these findings are aligned with the overall findings of the 7th Environment Action Programme Evaluation, which identified a lack of implementation, investment, information and integration as the main challenges for EU environment policy (EC, 2019b). In parallel to these underlying factors that hinder or delay implementation, a number of EU-level drivers support Member States in implementing the Directive, especially EU funding which helps Member States cover the costs of implementing the UWWTD. EU funding has also led to more integrated regional development, as it required the adoption of WFD RBMPs as a precondition (ex ante conditionality) of receiving funding ( Regulation No 1303/2013 ). Over the three financing periods since 2000, a total of EUR 38.8 billion of cohesion policy funding was allocated to the EU waste water sector (see financing the UWWTD implementation) (Cowi et al., 2019, p. 62). Acknowledging the scale of expenditure required to implement the UWWTD successfully, in parallel to the Evaluation the Commission launched a joint study with the OECD on investment needs and financing options in the EU water sector. This includes comparative assessments of Member States’ investment needs and targeted Member State workshops to discuss future financing options. Aside from this study, the Commission also carries out a number of other compliance promotion activities. It has set up a UWWTD expert group, which typically meets at least once every two years to discuss the results of the latest reporting exercise, as well as findings from other relevant studies. It also participates in meetings with candidate/accession countries to prepare for UWWTD implementation. Additionally, the Commission carries out UWWTD-related studies to investigate specific issues (e.g. the COD requirement and the use of IAS), publishes guidance (EC, 2001) and supports research in the waste water area through its cohesion policy funds, the LIFE programme and the Horizon 2020 financing mechanism. Other compliance promotion programmes include technical assistance through JASPERS and the TAEIX REGIO Peer 2 Peer and TAIEX EIR Peer 2 Peer programmes. These programmes are demand-based and give Member States an opportunity to exchange experiences and learn from each other. In addition, the Commission can provide structural assistance through the Structural Reform Support Service . For instance, in 2018 the Scottish Water Industry Commission worked with the Romanian regulator through this service to analyse inefficiencies in the water sector and develop ideas for improvement. Aside from funding, infringement procedures were also identified as an effective way to increase implementation levels. Active legal enforcement is a tool that the Commission uses to foster compliance with the UWWTD. Overall, more than 40 CJEU rulings were issued by June 2018 (Table 5) and this does not include infringement cases that were closed before reaching the Court. Infringements can lead to penalties, which in the past have ranged between EUR 2 million and EUR 25 million for lump sum fines and between EUR 2 800 and EUR 8 000 for each day of delay. Infringement procedures are generally rather slow, but they do drive Member States to gradually become fully compliant. Member States Infringement cases per time period with final ruling 1991 - 2000 2000 - 2005 2005 - 2010 2010 - 2015 2015 - 2018 Total: 1991 - 2018 EL 1 2 1 1 0 5 ES 1 4 0 0 0 5 IT 2 1 2 0 0 5 PT 0 2 2 0 0 4 FR 1 2 1 0 0 4 UK 1 2 0 1 0 4 BE 2 0 1 0 0 3 LU 0 1 0 0 0 1 IE 0 1 0 0 0 1 FI 0 1 0 0 0 1 SE 0 1 0 0 0 1 DE 1 0 0 0 0 1 Total number of infringements cases with final ruling 9 17 7 2 0 35 Total number of referred agglomerations in the final judgments of the CJEU 168 129 255 17 0 569 Financing UWWTD implementation The assessment of late implementation indicated that Member States’ difficulties with financing UWWTD implementation were a major cause of implementation delays. The UWWTD does not prescribe how Member States should organise their water supply and waste water sector, and Member States use different models of governance. The management models used most often are public- and delegated private management. In the first case management remains in the hands of the public and, in the latter, the public entity contracts a private company to manage operations. The infrastructure is almost always owned by public authorities (EurEau, 2018). The UWWTD also does not prescribe how Member States should finance infrastructure and the operation and maintenance of collection systems and WWTPs. However, both the TFEU and the WFD do provide indications on how water services should be financed. Article 191(2) TFEU states that ‘environmental damage should as a priority be rectified at source and that the polluter should pay’. Article 9 of the WFD, under which the UWWTD is a ‘basic measure’, requires that Member States ensure that adequate contributions are received from the different water uses. This is meant to recover costs of water services based on economic analyses and by taking into account the ‘polluter pays’ principle. When choosing their approach, Member States should consider possible social, economic and environmental effects. In terms of financing, the OECD’s analysis shows that Member States use a mix of public budget and water tariffs to finance their water supply and waste water sectors (Figure 25). Some Member States manage to almost entirely finance their water supply and waste water sector through revenues from water tariffs (e.g. DK, UK). Others like IE, CY and LU are heavily relying on budget transfers. Figure 25 Sources of funding for water supply and sanitation services per Member State as annual average over the 2011-2015 period . Source: OECD (forthcoming – draft findings) A number of Member States have struggled to meet the investment requirements related to UWWTD implementation. For instance, Case C-293/05 IT pleaded that substantial funds are needed to construct the infrastructure needed and that this was the reason for delayed implementation. The Court rejected this argument. Budgetary constraints were also raised by BE as an argument for delayed implementation. In terms of future investment needs, the OECD assessed the total additional expenditure that each Member States needs to spend to reach compliance. As shown in Figure 26, IT, ES and RO, but also PL, BG, PT, SK and HR need to increase their expenditure to reach compliance. Figure 26 Total additional expenditures to 2030: Business-as-usual (BAU) + Compliance + Efficiency. Source: OECD (forthcoming – draft findings).

At EU aggregate level, to reach full compliance with the UWWTD, a further EUR 253 billion would need to be spent between now and 2030. The additional expenditure needed to comply with the revised DWD (and to provide more access to water and improve system efficiency) and the UWWTD can be broken down by Member State. Figure 27 shows that, apart from DE, all EU Member States need to increase their spending by more than 25% compared to what is currently being spent (baseline level). Some Member States need to spend more than double what they currently spend (e.g. RO). Figure 27 Annual additional expenditure needed by 2030 per Member State, as a percentage compared to the baseline expenditure level. Member States have to not only achieve compliance with the UWWTD, they also have to maintain it. The patchy information on investment in infrastructure renewal shows that Member States are potentially not spending enough to ensure continuous compliance. According to the EU water industry association EurEau, given that collection systems can last for several decades, an annual renewal rate of 1% could be acceptable. However, this level is not met in many countries. In many Member States, water tariffs cover only operational costs and not the amortisation of infrastructure or renewal (EurEau, 2017) . Under WFD reporting, there is no overview of how cost recovery is applied across the water sectors of the 28 EU Member States. In its 2nd RBMP assessment, the Commission noted that Member States have improved their general water pricing policies by fulfilling the precondition for receiving funding for water under the European Structural and Investment Funds for 2014-2020 (EC, 2019c). There is no evidence of different cost recovery strategies having a major effect on the internal market. Generally, in the cost structure of European industries, the cost of water is relatively modest compared to that of raw materials, energy and wages. A mix of tariffs, taxes, and EU funding can be used to meet the investment needs required to achieve UWWTD compliance. This is supported by Article 9 of the WFD, which requires ‘adequate contribution of the different water uses…to the recovery of water services’. The ‘polluter pays’ principle should be respected as regards waste water, and so households and industry, as the primary polluters, are usually charged to a certain extent. The structure of water tariffs applied to households varies between Member States, though often contains one fixed and one volumetric component. The actual price is often set at local level, whereas the tariff structure is often decided at national level (EurEau 2018). Industrial dischargers are usually required to acquire installation permits if they release their waste waters in the urban waste water collection system. These are issued either under the IED for bigger industries or at local level for smaller activities. Permits usually require industrial dischargers to contribute financially to the treatment of their releases in WWTPs. Sometimes they pay based on their own assessment of what is contained in their waste water, which might not reflect the true level of pollution they cause. In other instances, regular sampling reflecting the actual pollution emitted is taken, and is verified by the local competent authorities. The affordability of water supply and waste water services to households in Member States can be assessed by dividing the total costs by the number of households in the individual Member States and comparing this to their disposable income. There is no one generally agreed level of how much a household should be able to spend on water services. The results of the OECD study show that, at current levels of water service charges, only RO’s and BG’s lowest income households deviate from the average (Figure 28) . Affordability issues are usually solved at national/local level, notably by introducing social tariffs, social quotas or other specific support (not covered by the OECD’s work). Increasing water tariffs is often unpopular with the public, which can cause politicians, especially at local level, to keep water prices artificially low, though this is also often done to protect lower income households. In IT, the issue of potentially raising water prices not only led to constant political debates but also to the organisation of a referendum in 2011. The referendum rejected the proposed reforms related to the water sector. The required investment was estimated at EUR 61/capita/year, but the actual investment made was EUR 33/capita/year. In terms of financing the water sector, affordability constraints can keep some Member States from make further progress, especially when expenditure related to waste water and the water supply sector is already a significant part of their GDP (Figure 29). Figure 29 Macroeconomic affordability of water supply and waste water collection and treatment (WSS) in EU Member States. Source: OECD (forthcoming – draft findings). Overall, Member States have flexibility in how to ensure sustainable financing of their water supply and waste water sector. Some rely too heavily on EU funding and need to ensure that their water sector will be financially stable when EU funding decreases. Others use high amounts of public budget transfers (which can include EU funding) and should consider increasing water tariffs, where possible, to ensure that compliance can be maintained over time. Of the 300 replies to the public consultation question on the UWWTD’s impact on the affordability of water services, only 37% indicated that it had a negative impact (with about 16% having no opinion or no answer). These 37% of respondents were mostly members of the public and public- and private WWTP operators. Over 244 replies to this question from members of the public, NGOs and water companies stressed that industry or other main polluters should pay for the needed treatment, referring to the ‘polluter pays’ principle. The costs of implementing the Directive have been met with substantial funding from the EU. Over the past three financing periods, most environmental EU funding has been allocated to the water sector. Cohesion Policy allocations for the water sector added up to EUR 57.7 billion: on EU aggregated level, EUR 20.7 billion in 2000-2006, EUR 21.5 billion in 2007-2013 and EUR 15.5 billion in 2014-2020 were allocated to the water sector (Cowi et al., 2019). In the 2007-2013 period, this contributed to about 7 million people in the EU being newly connected to or having improved waste water services. The decline in allocations is explained by the fact that some Member States (e.g. EE) have now met their basic needs by completing the infrastructure, and by the fact that the Commission considered that in the 2014-2020 period EU funding for basic environmental infrastructure should be focused on less developed regions (ibid.). Over the past three periods, Member States invested the lion’s share into the waste water sector compared to the drinking water sector, with the waste water sector receiving EUR 38.8 billion of the EUR 57.7 billion. Over all periods, Cohesion Policy funded more than 50% of all water sector-related expenditures in EE, LV and HU. EU investments funded more than 35% of all expenditures in LT, BG, MT, RO, PT and SK (ibid.). At the aggregated EU level, Member States covered about 25% of the total expenditure with EU funds. Besides cohesion policy funding for direct investment in the water sector, EU funds (including cohesion policy funds, Horizon 2020 and LIFE funds) also supported research in the EU water sector. Between 2000 and 2017, the EU financed a total of 138 LIFE projects related to waste water treatment (EC, 2019d). To summarise the discussion above, there are a number of financial and management issues when it comes to the economic aspects of implementing the UWWTD. Financial issues related to UWWTD implementation include the following: 1) full cost recovery can in some Member States be constrained by affordability, 2) Member States’ economic situation and their ability to use loans, 3) national co-funding when EU funding is being used, and 4) financing sources are not sufficient for the maintenance of infrastructure. Management and associated issues mainly relate to 1) Member States’ ability to use funds effectively, 2) the lack of financial sustainability of investments in infrastructure, 3) issues with national procurement law, and 4) the possible lack of (technically and financially) competent contractors. Terms and obligations in the UWWTD

The Evaluation also assessed the clarity of the Directive’s terms and obligations. If terms and obligations are unclear, this can lead to delayed implementation or reduce the effectiveness of the Directive. Overall, the Directive was found to be clear and straightforward in its intervention logic and enforceability. It sets out clear actions to be taken by Member States and clear deadlines for when these have to be accomplished. This clarity has supported the Directive’s correct and timely implementation and its effectiveness. Stakeholder respondents to the public consultation confirmed that the Directive is clearly drafted to a large (22%) or to some extent (66%) (n=301). Only 4% of respondents replied that the Directive is not clearly drafted and 8% indicated that they do not know. Nevertheless, a few terms and obligations have been identified as not entirely clear. This has been noted by stakeholders, as well as through cases where the CJEU had to intervene or where further clarification through exchanges between Member States and Commission had to be sought. Such unclear terms include for instance ‘storm water overflows’, ‘unusual situations’ and ‘sufficiently concentrated’ in connection with ‘agglomerations’ (see storm water overflows and IAS, and Annex 4, terminology) and the obligations related to these. Although not mentioned in the UWWTD, the term ‘tertiary treatment’ was also often mentioned by stakeholders as unclear. Aside from these specific terms, the requirements on water reuse and sludge reuse were also found to be unclear, with plenty of room for interpretation of the meaning of ‘whenever appropriate’ as well as lack of clarity on which requirements apply if water and sludge were to be reused and for which purposes they may be reused. The questions related to water reuse have been clarified through the Commission’s proposal for a regulation on water reuse (EC, 2019d). The main terms discussed in the Evaluation to assess impact on the UWWTD’s effectiveness are ‘storm water overflows’, ‘urban runoff’, IAS, ‘scattered dwellings’ and eutrophication. As shown in Figure 24, IAS and SWOs are estimated to be a sizeable contributor to remaining loads that could be avoided. Storm water overflows (SWOs) and urban runoff Next to non-compliant agglomerations, storm water overflows (SWOs) and urban runoff account for a significant proportion of the BOD load. This could be avoided through full control of SWOs (Figure 23). The UWWTD only includes a footnote on SWOs, stating that “…during situations such as unusually heavy rainfall, Member States shall decide on measures to limit pollution from storm water overflows. Such measures could be based on dilution rates or capacity in relation to dry weather flow or could specify a certain acceptable number of overflows per year.” The Directive does not define what constitutes ‘unusually heavy rainfall’ or an ‘acceptable number of overflows per year’. It also does not require the monitoring of overflows. Other Directives, such as the WFD, BWD and MSFD, do not address SWOs directly either, even though their objectives can be affected by SWOs. However, as these Directives set quality standards for water bodies and require water quality monitoring, measures addressing SWOs can be taken under them. In recent cases, the Court held twice that as ‘unusually heavy rainfall’ is not defined in the Directive, “it is legitimate for the Commission… to adopt guidelines” (para. 61) ( Case C-310/10 , see also: Case C-427/17 ). There are discharges from SWOs in cases of heavy rainfall events, when urban runoff enters the combined system and when the downstream collecting system does not have the capacity to convey all flows, domestic waste water and the urban runoff, to treatment. Urban runoff entering the sewer can carry several pollutants, such as heavy metals, hydrocarbons, urban pesticides and litter (including microplastics), from a variety of urban diffuse sources (e.g. pollution in streets and public places). The first flush is often (not always) more contaminated than later parts (Gupta, K & Saul, A., 1996; Barco et al., 2008). These overflows ensure that sensitive environments, public places and property are protected from flooding and that WWTPs are not overloaded during events during which the system’s normal operating system capacity is exceeded. Overloading can lead to their poor functioning and severe environmental risks. According to information reported under the 2nd round of RBMPs, SWOs were the cause of 4% of the EU’s surface water bodies failing to achieve good ecological status (Figure 3) (EEA, 2018b). Modelling demonstrates that a significant proportion of the remaining load, which could be avoided, comes from SWOs, though it assumes that these are not addressed adequately at the moment (Figure 30 above). Modelling results show that, under assumed full compliance with the UWWTD, SWOs can contribute to 50% or more of the remaining load in some Member States where there are no management measures in place. Where SWO management measures are in place, loads can be substantially reduced (Figure 30 below). Still, the aggregated loads from SWOs in one region can be equivalent to those of an entire agglomeration of tens or hundreds of thousand p.e. The pollutants for which SWOs represent a potentially significant share of the total load to the environment are those that are usually well removed in WWTPs (coliforms, BOD, to some extent P and certain chemicals) (see Annex 4, storm water overflows). More frequent heavy rainfall events under a changing climate will further aggravate this issue. These modelled estimates are developed at such a scale that they do not reflect the impact of SWOs at a local level. In its recent report on chemicals in European waters, the EEA identified overflows as the main pressure for a number of chemicals such as nonylphenol, metals, hexachlorocyclohexane and to a lesser extent for some herbicides. However, the EEA acknowledges that an assessment of the different sources and pathways for chemicals is difficult due to a lack of reported data (EEA, 2018f). Member States have taken a number of measures to address SWOs. For instance, in England and Wales ‘event duration monitoring’ is used to determine event frequency and duration. In AT, international design practices such as mass balances are used to simulate the consequences of heavy rainfall events; where results show that WWTPs do not have the capacity to adequately deal with flows, the upstream collecting system is upgraded. ES has determined that SWO discharges need to be limited to 15-20 occurrences or to 10-15% of the yearly runoff volume. In DE, use is made of constructed wetlands that can retain peak flows, reduce suspended solids by filtration and reduce soluble particles through adsorption and biological degradation. At ‘big city’ level, Copenhagen adopted a cost-effective approach to deal with flows that did not focus on upgrading the upstream collecting system. This integrated approach includes rainwater-harvesting systems, urban green spaces that can be infiltrated by storm water, special rooftops and diversion of rainwater into streets that can serve as channels. In Rotterdam, a full-scale water square that can retain up to 2 000 m3 of rainwater was built and can be used for leisure activities in dry weather conditions (Urban Water Atlas, 2018). ‘Urban stormwater is one of the biggest problems facing city infrastructure waterways today. Urban cloudbursts and the resulting rapid stormwaters that overflow along surfaces and in networks are more and more common in cities due to climate change, increasingly impervious surface areas, aging infrastructure and often undersized, centralised stormwater networks.’ Urban Water Atlas (2018), p.26 From a monitoring perspective, new technologies to deal with SWOs include real time control (RTC) of collecting systems to maximise combined sewage retention during rainfall events and minimise discharges going directly to receiving waters, by regulating flows. RTC systems often integrate a high number of data sources such as weather and water gauge measurements, data from surveillance cameras, and detailed hydraulic and water quality models, based on asset information. Stakeholders representing Member States and industry raised the issue of the Directive’s lack of clarity regarding SWOs during the public consultation, the dedicated SWO workshop and the major stakeholder conference. As an example, the lack of an EU-wide definition for ‘spill’ – meaning duration, volume etc. – was frequently mentioned during the workshop. When urban runoff does not enter the sewer, it may directly enter water bodies. According to Figure 24, under full implementation of the UWWTD, urban runoff is the main avoidable source of BOD loads. The WFD does not contain a specific requirement for dealing with urban runoff, but Member States should put in place appropriate measures if they identify it as a pressure. This includes, for example: if runoff contains priority substances at levels that could result in failure to meet the environmental quality standards set for surface waters under the EQSD; if it contains priority hazardous substances whose emission to the aquatic environment should be phased out, or; if it results in the discharge of significant quantities of other pollutants that individual Member States should identify as river basin specific pollutants (EC, 2019f). Urban runoff causes failure of 3% of the surface water bodies in the EU to meet good ecological status according to information reported under the 2nd RBMPs (EEA, 2018). When untreated, the associated loads can be equivalent to or even higher than those of waste water from WWTPs. For instance, total suspended solids (TSS) in urban runoff can correspond to several million p.e. across the EU (Figure 31) (Grizzetti et al, 2017). In the absence of a holistic approach to cover urban water management, these kinds of loads might in the future represent a more substantial problem than waste water, especially in light of increasing numbers of heavy rainfall events in times of climate change and increasingly more impervious surfaces that do not allow the soil to absorb rain water (EEA, 2017). Urban sources as well as agricultural runoff entering sewers were named as important sources of pollution to water bodies by 45% and 74% of the public consultation respondents respectively (n=608). Only 2% and 0.2% respectively believe that these sources are not relevant, and 16% did not provide an answer. Authorities, water industry and NGOs were more likely to state that this is an important source than citizens.

Individual and other appropriate systems (IAS) IAS are considered to be another source of pollution, as shown in Figure 24. To understand whether the Directive leads to effective co