<p>The private sewage systems in Sweden releases around 600 tons of phosphorus per year, compared to about 350 tons from municipal sewage treatment plants, and they account for approximately 21% of the total anthropogenic discharge of phosphorus into Swedish waters. About 40% of Sweden's nearly 1 million private sewage systems are inferior with respect to emissions to surface and groundwater.</p><p> </p><p>The technology of small sewage plants is under development and knowledge of treatment effects for different solutions is poorly consolidated. Municipal authorities lack resources to keep up with the technologic development and assess the reliability of the treatment performances that suppliers report for their products. The thesis aims to conduct a market review and evaluation of wholly or partially prefabricated small sewage plants, to make it easier for municipalities and property owners to assess different technical solutions. The goal is a compilation of the products on the market, evaluated on the basis of the reliability of specified degrees of reduction.</p><p>Information on sampling procedures and test results were collected through a questionnaire to all active suppliers and the responses were then used to classify the products. The results suggest that most products have been extensively tested and shown a good cleaning ability. Those test results should be readily available to property owners and state authorities so that they do not have to make their own inquiries to verify the functionality of each product. Tests should also be entered in the central gauge database that is being constructed on behalf of the Swedish Environmental Protection Agency.</p><p>A case study was conducted in five municipalities in order to investigate how the handling of private sewage plants can be improved. The current work situation, what improvements that are demanded and what the administrators think of various suggestions for action was identified through interviews. According to the results, all administrators use the Environmental Protection Agency's general recommendations in their work though most of them experience difficulties to interpret the recommendations, and demand clearer rules and guidance. Almost all administrators want to increase the use of digital data and collaborate more across municipal boundaries. Another interesting finding is that the strategies to define the levels of environmental protection differ widely both between the five municipalities and between administrators within the municipalities. Better coordination is needed to enhance legal certainty and predictability for property owners and contractors.</p> / Kunskapscentrum Små Avlopp

The private sewage systems in Sweden releases around 600 tons of phosphorus per year, compared to about 350 tons from municipal sewage treatment plants, and they account for approximately 21% of the total anthropogenic discharge of phosphorus into Swedish waters. About 40% of Sweden's nearly 1 million private sewage systems are inferior with respect to emissions to surface and groundwater.   The technology of small sewage plants is under development and knowledge of treatment effects for different solutions is poorly consolidated. Municipal authorities lack resources to keep up with the technologic development and assess the reliability of the treatment performances that suppliers report for their products. The thesis aims to conduct a market review and evaluation of wholly or partially prefabricated small sewage plants, to make it easier for municipalities and property owners to assess different technical solutions. The goal is a compilation of the products on the market, evaluated on the basis of the reliability of specified degrees of reduction. Information on sampling procedures and test results were collected through a questionnaire to all active suppliers and the responses were then used to classify the products. The results suggest that most products have been extensively tested and shown a good cleaning ability. Those test results should be readily available to property owners and state authorities so that they do not have to make their own inquiries to verify the functionality of each product. Tests should also be entered in the central gauge database that is being constructed on behalf of the Swedish Environmental Protection Agency. A case study was conducted in five municipalities in order to investigate how the handling of private sewage plants can be improved. The current work situation, what improvements that are demanded and what the administrators think of various suggestions for action was identified through interviews. According to the results, all administrators use the Environmental Protection Agency's general recommendations in their work though most of them experience difficulties to interpret the recommendations, and demand clearer rules and guidance. Almost all administrators want to increase the use of digital data and collaborate more across municipal boundaries. Another interesting finding is that the strategies to define the levels of environmental protection differ widely both between the five municipalities and between administrators within the municipalities. Better coordination is needed to enhance legal certainty and predictability for property owners and contractors. / Kunskapscentrum Små Avlopp