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Decentralised wastewater treatment in Europe

The following text is an excerpt from a document which can be downloaded on the SPIN website under Industry Sectors - "Decentralized Wastewater Treatment for SMEs - background paper". Here you will also find the references in full length.

Outline of the Current Technical Potential of Waste water and Rain Water Treatment/Characterisation of the Field of Technology, especially relating to SMEs

Considering the demographic change, climate change and the scarcity of resources in many countries of the world, the necessity to think about existing settlement structures and infrastructures increases.
Thereby closing the loop on water plays a major role.
The decentralised waste water and rain water treatment will be of particular interest in Europe. Individual concepts can be realised with isolated solutions, consisting of smaller treatment units for several houses or smaller settlements.
Water reuse systems as well as storm water management to protect the resource water are key elements of a sustainable water management. The goal is not only to recycle used water to the point that it can be fed back safely to the environment, but to treat it to a level for reuse. With the decentralisation, the existing demand for water supply and waste water disposal can be covered efficiently. This is a chance for SME (Small and Medium Enterprises), since an adapted water management leads to the reduction of investment and operation costs /UBA 2007/.

In addition to the conventional decentralised waste water treatment with small waste water treatment systems and small sewage treatment plants, sustainable sanitation concepts can be applied. Sanitation concepts concerning the collection and direct treatment of separated waste water streams such as rain water, grey water, faeces and urine to produce process water or fertilisers, contribute to the reduction of resource consumption and have been moved into the focus of attention in the past few years. The application areas of treated water such as grey water and rain water are versatile. They can be used as process water in the household, on sports facilities, on camping sites or even in hotels. Furthermore, treated water is suitable for the irrigation of lawns, golf courses or parks as well. Treated water can be used in the industrial, commercial and public domain. The most important condition for the reuse of treated water is good water quality and the prevention of health risks. /DWA 2008, Londong 2008/ Defrain u. Moosdorf 2009/. (…)

The fast and complete rain water disposal, as it is still nowadays mainly realised in settlement areas, must be replaced by more sustainable concepts such as rain water management. The performance of decentralised systems often surpasses conventional systems in regard to the reduction of peak discharges. Furthermore, decentralised systems lead to the protection of the water balance, since the discharge amounts can be kept low. A very good treatment efficiency of rain water is ensured by soil percolation. Decentralised systems are qualified particularly for development areas and areas not yet connected to a drainage system. /UBA 2009/

In the domain of decentralised waste water and rain water treatment, there are many more business areas than the production and distribution of decentralised treatment units for small and medium-sized enterprises (SME). The planning and consulting for individually adjusted concepts for waste water disposal or rain water management as well as the monitoring and maintenance of the plants require a professional and competent support. A cost management will be necessary for new sanitation concepts to distribute the expenses amongst the individual users. The treatment of waste resulting from the operation of decentralised waste water and water plants is also from particular importance with regard to the recycling economy.

For small and medium-sized enterprises who want to establish themselves in the outskirts of cities or rural areas without the complete infrastructure for public water supply and waste water disposal, decentralised concepts offer an economical and financial possibility for its realisation. An in-house water recirculation system, process water production with grey water and rain water treatment are conducive to the reduction of water costs and make the company more independent from water supply and waste water management companies. These new systems provide a considerable contribution to environmental.

Characterisation of the Legal Framework

Waste water and rain water treatment plants are subjected to the water law. For the construction, operation and use of the plants, further technical requirements and standards are relevant. Decentralised waste water plants are usually construction products and so they are subjected, in addition to the water law, also to the construction legislation. For rain water utilisation and water preparation plants there are additional legal and technical regulations and standards concerning the reuse of the water. Since the percolation of rain water can also carry pollutants into the soil legal requirements for soil protection must be taken into account. /UBA 2005/

The water framework directive, the directive on urban waste water treatment as well as the construction products directive form a significant framework legislation for Europe in this area. Every member state is obliged to implement and substantiate the guidelines from these directives in their national legislation.

2000/60/ EC Water Framework Directive
Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 Establishing a Framework for Community Action in the Field of Water Policy (WFD) /8/

With the Water Framework Directive (WDF) “Directive 2000/60/EC of the European Parliament and of the council of 23 October 2000” , the commission of the European Union (EU commission) has realigned the water protection policy. The directive which came into effect in December of 2000 pursues a new approach to water resources management. The goal of this directive is the establishment of a framework for community action for the protection of inland surface waters, transitional waters, coastal waters and groundwater for the purpose of:
  • Prevention of the deterioration of the waters,
  • Protection and improvement of water quality,
  • Promotion of sustainable water use,
  • Long-term protection of the existing resources,
  • Reduction and gradual phasing-out of discharges and emissions,
  • Reduction and prevention of the pollution of ground water,
  • Reduction of the effects of floods and droughts.

Every Member State is obliged to account for their river basins and put up management plans which should be sent to the EU commission by March 2010. The goals “good ecological status” and “restoration of the ecological function of the waters” are planned to be achieved by the year 2015.

91/271/EEC Urban Waste Water Treatment
Council Directive 91/271/EEC of 21 May 1991 Concerning Urban Waste Water Treatment /9/

The purpose of this directive is to protect the environment from harmful effects caused by waste water. This directive comprises the collection, treatment and discharge of urban waste water and the treatment and discharge of waste water of certain branches of industry.
In this directive, urban waste water is defined as domestic waste water or a mixture of domestic and industrial waste water and/or rain water.
The member states are obliged to equip all communities with more than 2000 PE with a sewer system. Furthermore, it must be ensured that communal waste water discharged into sewer systems receives a secondary treatment or an equivalent treatment before being discharged into waters. In order to discharge industrial waste water into the sewer system and into communal waste water treatment plants, regulations need to be set and/or a permit has to be issued by the competent authority.
If the establishment of a sewer system is not justified, because it would not involve a benefit for the environment or would be associated with excessive costs, individual systems or other suitable measures which ensure the same level of environment protection are necessary. A permit for the discharge of communal waste water from waste water treatment plants from municipal areas with less than 2000 PE may only be issued, if a process and/or disposal system ensures that the receiving water bodies comply with the relevant quality objectives of the provisions given by every relevant guideline of the community.
According to article 12, purified waste water should, if possible, be reused. Contamination of the environment is to be kept to a minimum.
Requirements for communal waste water are defined in annex I. Annex II shows criteria for the designation of sensitive and less sensitive areas.