Sustainable Management of Wastewater in Rural Areas

Transcription

1 Sustainable Management of Wastewater in Rural Areas

2 The Depuranat Project: Sustainable Management of Wastewater in Rural Areas L. Vera 1, G. Martel 1, J.J. Salas 2, N. Sardón 2, R. Nogueira 3, A. G. Brito 3, J. A. Faby 4, A. Ramón 5 1. Water Department R & TD Division. Canary Islands Institute of Technology (ITC). 2. Department of Applied Research, New Water Technologies Centre (CENTA). 3. IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho. 4. National Centre for Water-Related Information and Documentation, International Office for Water (IOWater). 5. Management and Planification of Territory and Environment (GESPLAN). II International Congress SMALLWAT07 Sevilla, November 2007

3 Introduction In the rural areas of Spain, Portugal and France, inside, or in the vicinity of, protected natural reserves, the population settlements are usually scarce and disperse, often lacking in sewage and adequate water treatment plants. The centralized wastewater treatment plants and their associated costs, both in terms of investment and maintenance, are not the only possible solution to the problem in rural areas, where there are also limited financial and management resources.

4 Introduction DEPURANAT was designed to promote the development of decentralised wastewater treatment systems using technologies of natural treatment and low energetic consumption and cost, and which include the re-use, with total guarantees, of the water, the nutrients and the bio-mass generated. DEPURANAT project s global aim was that the designed and operated systems were totally integrated into the environment and involved the direct participation of the local population. This initiative was co-financed by the European programme INTERREG III - B Atlantic Area, and depended upon the close collaboration of entities of diverse nature, local authorities, research centres and technological development, together with private companies and associations.

5 Introduction France. L Office International de l Eau (OIEAU) Portugal: Universidade do Minho (UMINHO) Spain: Centro de Nuevas Tecnologías del Agua (CENTA) Instituto Tecnológico de Canarias (ITC) Gestión y Planeamiento Territorial y Medioambiental, S.A. (GESPLAN)

6 Introduction Portugal: Câmara Municipal de Vila Verde (CMVV) Spain: Cabildo de Tenerife Mancomunidades de Municipios de Medianías y Sureste de Gran Canaria

7 Introduction Natural Reclamation Systems (NRS) have been conceived as a matter of implementing complex systems of social, environmental and economic integration which would allow for a close-knit fit between the activities generating of wastes, the people of the area, the local environment and the valorisation of by-products generated from each wastewater treatment system. The development of this type of systems involved the design and construction of several demonstrative pilot projects to be implemented previously in order to establish successful experiences, methods and sufficient tools to dispel any further uncertainties and generate confidence in the results.

8 Methods Depuranat works were organised over four different scientific and technical programmes: 1. Experimentation and demonstration of the technological, social and environmental aspects of the by-products of the system and the way to which they can be made use advantageously. 2. Market study, economic and environmental feasibility of the NRS. 3. Development of a methodology to study the potential of the application of the NRS in any given territory. Applications, by way of demonstration, in complex island environments. 4. Development of support tools for decision-making.

9 Methods 1. Experimentation and demonstration of the technological, social and environmental aspects of the by-products of the system and the way to which they can be made use advantageously. 4 work packages in this programme: Design of pilot wastewater treatment plants. Construction and adjustment of pilot projects. Evaluation and control of pilot wastewater treatment plants and potential byproducts. Development and evaluation of social and environmental integration.

10 Methods 1. Experimentation and demonstration of the technological, social and environmental aspects of the by-products of the system and the way to which they can be made use advantageously. Establishment of criteria and information for choosing new locations and pre-existent wastewater treatment plants to be included in DEPURANAT project monitoring. Design of NRS and exploitation programme to be implemented in the new building projects. Definition of proposals for re-adjustment of existing plants. Establishment of a shared protocol of monitoring and Development of specific protocols for the agronomical evaluation of the recycled water in each influenced area. Analysis and classification of the wood and vegetable biomass generated in the NRS. Monitoring of the environmental parameters of the NRS. Research, development and application of methods at enhancing the social acceptance of the NRS.

11 Methods 2. Market study, economic and environmental feasibility of the NRS. This programme was focused to define financial indicators for the overall design of the empirical functions of costs, together with a preliminary evaluation of the potential market for these technologies. The environmental evaluation implied: Monitoring in situ the environmental parameters Application of the method Life Cycle Analysis (LCA) of different potentially usable technologies: Constructed Wetlands, Green Filters and Activated Sludge. Included phases in LCA: building, operation, maintenance and dismantling of the systems Different descriptors were used in order to reflect the environmental impact of each system, e.g. global warming.

12 Methods 3. Development of a methodology to study the potential of the application of the NRS in any given territory. Applications, by way of demonstration, in complex island environments Several tools were designed for the drawing up of maps of potential implementation of NRS. Methodology based on GIS, taken into account: peculiarities and specific nature of the rural environments: limiting ecological or geographical factors: climatic conditions, altitude, slopes of the land, types or uses of the land. potential demand for implementation of NRS in rural areas: existence and location of small or medium-sized hamlets which do not have a general sewage system.

13 Methods 4. Development of support tools for decision-making Development of integrating software of the implemented experiences in the project and the knowledge collected from the existing literature. The aim: a software that can help at professionals for taking decisions in all of the cases, tackling all the problems associated to small-scale wastewater treatment.

14 Results and Discussion 1. Experimentation and demonstration 12 pilot projects of wastewater treatment were adapted and submitted to constant monitoring or built, as way of demonstration. 1 green filter in VilaVerde, North of Portugal. 2 parallel functioning green filters in the Planta Experimental de Carrión de Los Céspedes (PECC) in Sevilla (Spain). 2 pilot installations (combination of anaerobic treatment, sub-surface flow constructed wetland refilled of volcanic ashes) located on Tenerife Island (Spain). 3 pilot plants (combination of facultative ponds, channels and gravel filters ) located in Gran Canaria and Tenerife Islands (Spain). 4 pilot installations with various combinations of wetlands (horizontal and/or vertical flow) in the PECC, in Seville, and in Gran Canaria Island.

15 Results and Discussion 1. Experimentation and demonstration Effluents quality: In accordance with the required levels of ED 91/271. Microbiological monitoring: Nematode eggs and other type of parasites: no detected Bacterial indicators and enteric viruses: reductions of 3-4 log 10 Agronomical quality for re-use (USEPA ): Irrigation of crops of indirect human consumption Recreational uses not involving human contact Environmental uses and recovering of natural wetlands

16 Results and Discussion 1. Experimentation and demonstration Social integration of the NRS: Organisation of various technical seminars with public participation. Method of analysis and specific recommendations to improve social integration: To establish optimum parameters of maintenance and management using protocols. Promoting the direct participation of the local people.

17 Results and Discussion 2. The Economic Study Function of costs analysis: Investment costs are similar over the different types of pilot projects. The variation in the cost of investment ( per P.E.) and the operational costs ( per P.E.) tend to diminish as the population increases. Operational costs are lower than for conventional systems. The price of water supply is a decisive factor for the economic feasibility of the NRS Coste anual de operación ( /p.e.) Coste de inversión ( /h.e.) Población servida (h.e.) Población servida (h.e.)

18 Results and Discussion 3. Environmental study and external factors Conclusions of the Life Cycle Analysis (LCA): Manufacture/production of the materials used in the building of the wastewater treatment systems (Activated Sludge and NRS) is the main contributor to their toxic and eco-toxic impact. The stage of dismantlement and final closing cause the least environmental impact. Building and assembly: the greatest impact of the Constructed Wetlands. General absence of nuisances such as unpleasant smells or mosquitoes. Landscape integration is adequate, producing positive visual impact. Higher contribution to the reduction of the global warming.

19 Results and Discussion 4. Market studies and territorial potential Maps of territorial potential application of NRS of Gran Canaria and Tenerife Islands show : More than 225,000 homes without sewage systems, the great majority on Tenerife Island. The wastewaters from cattle installations and agricultural product processing plants are particularly relevant and worrying.

20 Conclusions DEPURANAT project has achieved collaboration and interaction of agents of varying characteristics: users, public authorities, businesses, professionals and researchers. It has been achieved a productive exchange of information, ideas, methodologies and technologies around of natural reclamation processes. There is a great potential of implementation of NRS in the European Atlantic Area. It is foreseeable potential receptiveness of management companies of wastewater systems given the economic advantages and the low environmental impact of these systems.

21 Acknowledgement European programme INTERREG III - B Atlantic Area by the financial support. All partners for their implication in the Project. All collaborators (researching groups, maintenance enterprises, local stakeholders and citizens) for the showed interest in this initiative. Thank you very much for your attention depuranat@itccanarias.org