C. Wastewater Treatment

73. Wastewater treatment coverage shows significant improvement over the last 15 years (particularly in EU member countries), but still remains the least developed aspect of water service provision. At the beginning of the EU expansion process in the region, wastewater treatment was significantly less developed than other aspects of water services provision, with about 35 percent of the total population in the region connected to any level of treatment in 2000 (Figure 32). The situation has been gradually improving following EU expansion in the region and large investments that have followed in EU member countries, but the region is still significantly behind other parts of Europe in the area of wastewater treatment.

74. There are large differences in level of wastewater treatment provision in the region, and while progress is being made, the region as a whole is still behind other parts of Europe. At present, 45 percent of the total population in the region is connected to wastewater treatment plants, but there are major differences in the percentage of population in individual countries connected to wastewater treatment, ranging from 97 percent in Austria to 2 percent in Kosovo (Figure 31). The share of population with wastewater treatment has been steadily increasing in all countries of the region over the last decade. However, there is a noticeable difference in coverage increase among EU member countries, and non-EU member countries (Figure 32), which indicates a major impact of EU structural fund investments in wastewater treatment infrastructure. At the same time, data also show only limited progress has been made in the Balkan countries that have not yet started the accession process (Bosnia and Herzegovina, FYR Macedonia, Kosovo, and Serbia). The relatively high initial level of wastewater treatment in non-EU countries (Moldova and Ukraine) can be explained by the higher level of attention to treatment of wastewater in the Former Soviet Union compared to Former Yugoslavia.

Nutrient removal requirement
in the Danube basin

If receiving waters are particularly sensitive waters, such as those already suffering from eutrophication, stronger reduction of nutrients (phosphorus and nitrogen) from wastewater effluent is required (so-called tertiary wastewater treatment). Due to the need to protect the Danube delta and the coastal waters of the Black Sea from eutrophication, a significant part of the Danube River basin population is required to have tertiary-level treatment. Deadlines for compliance with the UWWT Directive vary, and for the EU15 (the original EU Member States) it was December 31, 2005. For the new Member States in Central and Eastern Europe, staged transitional periods have been set within the individual Accession Treaties. In principle, however, these transitional periods do not exceed 2015 (except in Romania, where agglomerations with less than 10,000 p.e. must comply with the directive by the end of 2018; and Croatia, which as a recent EU member, has deadlines between 2018 and 2023).

75. With all the progress made, the Danube basin region is still substantially behind other parts of the EU, particularly in relation to tertiary treatment. Almost 20 years after the adoption of the UWWT Directive, wastewater treatment is high in the EU15, with 97 percent of the population in Central European countries and 84 percent of the population in Northern European countries connected to a wastewater treatment plant compared to only 67 percent of the population in the EU countries of Eastern Europe. Due to much focus on nutrient removal from wastewater, tertiary treatment of wastewater has seen a very significant increase over the last decade throughout the EU. Currently, about 50 percent of the population in the new Eastern European member countries has tertiary level of treatment, which is still much lower than the EU average but which represents a 30 percent increase compared to 10 years ago. There are major differences in tertiary treatment in the region, with about 90 percent of the population in Austria, 60 percent in the Czech Republic, and 20 percent in Slovakia (SoS Data collection and EEA 2015) connected to tertiary treatment, while tertiary treatment remains nonexistent in the southern part of the region (including Bosnia and Herzegovina, Kosovo, FYR Macedonia, Montenegro, and Serbia)

76. EU countries have committed themselves to comply with wastewater collection targets, and face different deadlines to reach full compliance. EU directives, as mentioned, require wastewater collection for all settlements with population above 2,000, although sewage treatment requirements vary by settlement size and sensitivity of the area. Among the EU countries in the Danube watershed, Bulgaria’s and Slovenia’s compliance rates with respect to wastewater collection are only 15 and 32 percent, respectively, while Romania is still “in transition” and will need to make significant efforts to meet future compliance deadlines (EC 2013, 2, Annex). Both Bulgaria and Slovenia are expected to meet compliance with wastewater collection in settlements with populations above 2,000 by 2015 (SoS data collection). Croatia still has a grace period, but needs to start working on closing the gap, since only 44 percent of its residents are connected to a public sewer system.

Technical standards in the Danube region
Technical requirements for design and construction of water supply and sanitation structures in all countries of the region are defined by national legislation (usually consisting of construction law and associated secondary legislation), and existing national technical standards, while those that are EU members are in compliance with EU design and construction requirements. Several countries in the region have traditionally relied on German DIN (Deutsches Institut für Normung) standards (Croatia, Slovenia), or the Former Yugoslavia JUS (Jugoslovenski Standard) standards (Bosnia and Herzegovina, Serbia), while some still use their nationally developed technical standards with the tendency to gradually adopt them to those used in EU countries. Former Soviet-era technical and construction standards (that are solid on technical grounds but often not concerned with economy of operation) still apply in countries that were part of the Former Soviet Union (Moldova and Ukraine). In newly created countries like Kosovo, development of technical standards and water supply and wastewater norms is an ongoing process, but the objective is development of standards based on EU requirements, while in the transitional phase, they are mainly using DIN standards as ready-made and widely respected technical norms.

Service standards and cost-effective solutions under EU directives
Neither the Drinking Water Directive (DWD) nor the Urban Waste Water Treatment Directive (UWWTD) includes specific service standards or requirements at the household level. However, throughout Europe, piped water and flush toilets on the premises, which go beyond the JMP definition of improved services, represent the most commonly accepted service level. Both the DWD and the UWWTD impose quality standards, however, and in the case of UWWTD, collection standards if water and wastewater are produced, which evokes the question of how to address in a cost-effective way those requirements, in particular in cases where there is no public infrastructure in place.
The UWWTD establishes the conventional wastewater collection and treatment systems as standard for agglomerations above 2,000 population equivalent, but also provides the option of individual or other appropriate systems, where a centralized system would produce no environmental benefit or because it would involve excessive costs. However, in such cases, those systems must achieve the same level of environmental protection, which in court cases (Case C-119/2002 Commission v. Greece) has been confirmed to mean discharges to the soil must be treated to the same level as discharges to water bodies, thus limiting the use of this clause. Recent Commission guidance generally limits the use of such systems to 2 percent of a given agglomeration.
Furthermore, in smaller settlements, centralized low-cost systems such as wastewater ponds and constructed wetland systems are extensive wastewater treatment options that are simple to operate, have a low energy demand, and can meet the requirements of the EU Urban Waste Water Treatment Directive for settlements below 10,000 population equivalent, even for sensitive areas. In addition, increasing attention has recently been given to modern onsite, decentralized, or semi-centralized wastewater management concepts that are already applied in several of the most advanced European countries (Germany, Holland, Sweden), particularly in rural and semi-urban areas. These concepts comprise collection, treatment, and disposal or reuse of wastewater from small communities (from individual homes to portions of existing communities) using many small sanitation/wastewater treatment facilities designed and built locally, that are more flexible, sustainable, and cost-effective (WECF 2010).