Good practices in the management of septic tanks Francisco Mira e Maria José Franco 9.º Congresso Mundial da Água Lisboa, 21-26 de setembro de 2014

1. Problem issues:
•High number of septic tanks uncontrolled, poorly sized and constructed with diffuse discharges, contaminating soil and water;
•Septic tanks without additional treatment, discharging directly on soil;
•Lack of knowledge from municipal authority regarding the location of a great number of septic tanks; these systems are installed and largely forgotten;
•Collection and transport of sludge from septic tanks by non-controlled operators and its discharge in inappropriate places. Adopted Measures
•Recommendation formulated by ERSAR;
•Establishment of the legal regime for the municipal services of public water supply, wastewater and urban waste management;
•The ERSAR requested information to the managing entity of the number of septic tanks which are controlled by municipality. .
CURRENT SITUATION
GOAL TO ACHIEVE
INTRODUCTION
Good practices in the management of septic tanks
Francisco Mira, Maria José Franco
ERSAR - Entidade Reguladora dos Serviços de Águas e Resíduos (The Water and Waste Services Regulation Authority), Portugal, www.ersar.pt; geral@ersar.pt
Phone: +351 210 052 200; Fax: +351 210 052 259
Over the past few decades, the use of septic tanks has been widely disseminated across Portugal, both as an individual and collective treatment solution. The management of septic tanks have become of significant importance to the operators due to increased environmental awareness of the populations and legal requirements. Users are responsible for the maintenance of individual septic tanks. The old age of many of these facilities and the fact that many are not licensed, mean that most of them are not registered and the operators have no information regarding their location, capacity or conservation condition. Currently, the use of this treatment solution should only occur when there is no public network available. However in order to promote compliance with this obligation, a good coordination between the operator and the licensor is deemed essential. ERSAR, aware of the importance that the management of septic tanks has to the operators, formulated a recommendation that aims to assist operators in the adoption of procedures, namely regarding the design, sizing, construction and maintenance of septic tanks and the collection and transport of sludge from septic tanks to their final destination. Another instrument that helped clarify this matter has been the legal regime for the municipal services of public water supply, wastewater and urban waste management, since it allows to clarify the responsibility over the collection, transportation and final destination of sludge from septic tanks, which befalls on the municipal services of urban wastewater sanitation. Nevertheless, the implementation of the current legal regime is still undergoing some difficulties.
Figure 2 – Relationship between existing housing without effective service by type
AVAILABLE DATA
The implementation of good practices in the management of septic tanks may improve the following aspects:
•Elimination/reduction of illegal discharges – the municipality ensures that the sludge from the septic-tank cleanups are taken to their final adequate destination;
•Register update – the municipality, as the sole provider of this service, has all the information available, hence able to know the location, the number and the capacity of the septic tanks (individual and collective), as well as their conservation condition;
• The information collected can influence the investment plans;
•Cost reduction – taking into account the specific needs, the operator may reduce costs by resizing and optimizing the equipment and human resources.
CONCLUSIONS
inspiring change
Figure 1 – Evolution of the number of collective septic tanks reported
With respect to the individual solutions, the extent of the problem is presented in the following table. Rural areas are those with a greater number of households with no connection to the public network. Although it is not possible to ensure the availability of public accommodations for all, situations persist in which the network is now available, showing a lack of incentives to promote the binding of these accommodations.
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References: [1] Recomendação IRAR n.º 01/2007 – Gestão de fossas sépticas no Âmbito de soluções particulares de disposição de águas residuais. ERSAR/LNEC (2012), [2]Guia de avaliação da qualidade dos serviços de águas e resíduos prestados aos utilizadores, 2ª geração do sistema de indicadores. Portugal. http://www.ersar.pt ERSAR (2013), [3]Relatório anual do setor de águas e resíduos em Portugal, Entidade Reguladora dos Serviços de Águas e Resíduos, 2011. Morais, M. (2013), [4]A aplicabilidade do decreto-lei n. º194/2009, na gestão das fossas sépticas. Otimização na Gestão de Fossas Sépticas, Santarém, 2013. Freixial, P. Andrade, I. (2013), [5]Boas práticas de gestão de fossas séticas, Otimização na Gestão de Fossas Sépticas, Santarém, 2013.
www.iwahq.org
As far as the collective septic tanks are concerned, these solutions were adopted to address the lack of treatment infrastructures in isolated places, where the connection to another public treatment system was not possible. Its maintenance must be carried out by the operators and, according to the information reported in the quality assessment of the service, the trend in the period between 2011 and 2013, presents a reduction of the number of collective septic tanks, as shown in the following figure, reflecting an increase in the availability of public sanitation system.
•Implement the law regarding the legal regime: the municipal authority verify the design, sizing and construction of the new septic tanks, is responsible by supervision of its maintenance and by the collection, transportation and final destination of sludge from septic tanks:
•Adoption of appropriate practices to the management of septic tanks as recommended by ERSAR:
•Registration of all septic tanks by the municipal authority:
•Registration of all cleaning operations performed.