The purpose of this study was to describe a) the status of the household sewage systems in the municipality of Nordmaling, b) to suggest areas in which a higher level of protection would be required and c) to investigate which type of technological choice was appropriate for which type of soil. A survey was used to investigate the status of the household sewage systems. The status was judged mainly on the age and treatment of water. Protected areas, the ecological status and data for phosphorus and nitrogen were used to locate areas in need of a higher protection. Map data from the Geological Survey of Sweden was used to identify common soil types in Nordmaling. Subsequently, the map was complemented and verified with a field investigation. In a next step, characteristics of the soil types were compared to the requirements of four different sewage treatment technologies; infiltration, constructed infiltration, incinerator toilets and household sewage plants. The study shows that the household sewage systems in Nordmaling are in general not in a good condition. Almost 70 % of the sewage systems are older than 20 years and their function is likely not sufficient. The study suggests that the following areas should be included in the list of objects with high protection: Lögde- and Öre river, Kronören, Järnäs peninsula, waters with an ecological status below “good” and the protected water resources. Except for infiltration, all sewage treatment technologies were assumed to give appropriate results for all soil types.

Water is essential for our daily life. Despite this, much of our water has become polluted and nutrient-enriched. One main factor contributing to the problem are private sewers. In total, there are nearly 1 million private sewers in Sweden, which represent one of the largest point sources of nitrogen and phosphorus. A survey was carried out to investigate the status of private sewers at Källsjön, Sollefteå municipality. In addition, four municipalities around Sollefteå have been interviewed about the implementation of legislation concerning private sewers. The study shows that sewers around Källsjön are seemingly in relatively good condition. However, 36% of the polled property owners have drains that are over 20 years old, and the function of these drains can be questioned. Interestingly, many of the surveyed property owners do not even know how old their drains are and what type of facility they have. Three of four interviewed municipalities are currently not performing any active control of private sewers. All municipalities provided information to property owners regarding current legislation. The study suggests that municipalities should act proactively to establish comprehensive inventories, a first step towards raising the standard of the individual sewers.

Made available in DSpace on 2015-05-14T12:09:28Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3492986 bytes, checksum: cb918a3cba1ca29e84bfc06dbb5b6d70 (MD5) Previous issue date: 2014-03-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The efficiency of removal of the biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids (TSS) and volatile suspended solid (SSV) were studied in two anaerobic reactors which received semi-settled effluent (flow limited around 3.2 times the average flow) of a septic tank, one being adhered growth (R1, with bed of gravel Nº. 4) and the other dispersed growth (R3 without support material for microbial growth). This system was installed in the University Residence at UFPB in João Pessoa-PB. The treated sewage came from two bathrooms that catered to a theoretical population of 4 inhabitants. Eleven samples of the effluent from the septic tank and the effluent from the reactors 1 and 3 were performed in the period between 28/02/2013 and 10/12/2013. The temperature and pH of the reactors were presented in the range 24.5 to 28.1 ° C and 7.3 to 8.1, respectively. Those values are from the anaerobic treatment of household sewage. The BOD5 removal efficiencies (32.8 and 27.1% in R1 and R3, respectively), COD (43.4 and 33.0% in R1 and R3, respectively), SST (56.2 and 48.0% in R1 and R3, respectively) and VSS (54.7 and 46.2% in R1 and R3, respectively) were high. It demonstrates a good applicability of these low-cost housing units which are devoid of collective sewage system in the reduction of pollution load released in water bodies systems. An analysis of variance showed no significant difference of 5% between the average of the corresponding parameters of the two reactors, suggesting that reactor that receives discharges from the attenuation peaks, there is no need of support means, which may represent a reduction in costs involved. / Estudou-se a eficiência de remoção de demanda bioquímica de oxigênio (DBO5), demanda química de oxigênio (DQO), sólidos suspensos totais (SST) e sólidos suspensos voláteis (SSV) em dois reatores anaeróbios que recebiam efluentes semi-regularizados (vazão limitada a algo em torno de 3,2 vezes a vazão média) de um tanque séptico, sendo um deles de crescimento aderido (R1, com leito de brita n°4) e o outro de crescimento disperso (R3, sem material suporte para crescimento microbiano). Este sistema foi instalado na Residência Universitária da UFPB, em João Pessoa-PB. O esgoto a ser tratado era proveniente de dois banheiros que atendiam a uma população teórica de 4 habitantes. Foram realizadas 11 coletas do efluente do tanque séptico e dos efluentes dos reatores 1 e 3, no período compreendido entre 28/02/2013 e 10/12/2013. A temperatura e o pH nos reatores se apresentaram na faixa 24,5 - 28,1 °C e 7,3 - 8,1, respectivamente, valores estes, propícios ao tratamento anaeróbio de esgotos domiciliares. As eficiências de remoção de DBO5 (32,8 e 27,1%, em R1 e R3, respectivamente), DQO (43,4 e 33,0%, em R1 e R3, respectivamente), SST (56,2 e 48,0%, em R1 e R3, respectivamente) e SSV (54,7 e 46,2%, em R1 e R3, respectivamente) foram elevadas. Isto demonstra a aplicabilidade desses sistemas de baixo custo a unidades habitacionais desprovidas de sistema coletivo de esgotamento sanitário, na redução da carga poluidora lançada em corpos aquáticos. Um teste de análise de variância demonstrou não haver diferenças significativas ao nível de 5% entre as médias dos parâmetros correspondentes nos dois reatores, sugerindo que, para reatores que recebam vazões com atenuação dos picos, não há necessidade do meio suporte, podendo representar diminuição nos custos envolvidos.