Bättre enskilda avlopp i Sigtuna kommun : möjligheter för bebyggelse i Odensala socken
There are around 855 000 on-site sewage systems in Sweden and some 1 800 of these are located in the municipality of Sigtuna. The Sigtuna local authority has set the goal that all sewage systems with insufficient function should be improved before the end of year 2010. A malfunctioning on-site sewa...
| Autor principal: | |
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| Formato: | L3 |
| Lenguaje: | sueco Inglés |
| Publicado: |
SLU/Dept. of Biometry and Engineering
2005
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| Materias: |
| _version_ | 1855572121118310400 |
|---|---|
| author | Hårsmar, David |
| author_browse | Hårsmar, David |
| author_facet | Hårsmar, David |
| author_sort | Hårsmar, David |
| collection | Epsilon Archive for Student Projects |
| description | There are around 855 000 on-site sewage systems in Sweden and some 1 800 of these are located in the municipality of Sigtuna. The Sigtuna local authority has set the goal that all sewage systems with insufficient function should be improved before the end of year 2010.
A malfunctioning on-site sewage system may cause three main problems: spreading of diseases, discharge of eutrophicating compounds and wastage of resources. The municipality strives to reduce these problems already at the stage of granting permits for installation of on site sanitation systems. The municipality has recently adopted new guidelines, which demands certain minimum reductions for different compounds. The guidelines also state that it is preferred that neighboring house-owners cooperate in jointly built and operated sewage systems and that the system should be able to recycle plant nutrients. Systems with infiltration to groundwater are accepted even though their function is hard to monitor.
This report focus on a specific area within the municipality but the results and discussion are also relevant to other similar areas. There are 54 households in the selected area. These were sorted into four categories according to their circumstances. Around 40 % of the households in the area have a legal sewage system and infiltration to groundwater and filter beds are the most common systems.
In this report package treatment systems and filter beds – combined with either chemical
precipitation or urine separation are evaluated, as well as connection to a large sewage treatment plant. These systems are compared regarding expected reduction, recycling potential and economy.
The systems studied ought to meet the reduction requirements set by the local authority, i.e. reduction of at least 50 % of the nitrogen and 90 % of both the phosphorus and oxygen demanding compounds. However, the reduction reported in different studies varies greatly between them and also between installations in the same study. A system with filter bed combined with chemical precipitation might have some difficulties to achieve the target concerning nitrogen removal while on the other hand urine separation might have problems to meet the target for phosphorus reduction.
To connect to the municipality's sewage treatment works means that theoretically 19 % of the nitrogen and 86 % of the phosphorus can be recycled and both package treatment systems and chemical precipitation in combination with filter bed have similar recycling potentials. Systems with urine separation differ by greater potential to recycle nitrogen but smaller to recycle phosphorus. Achieving recycling of plant nutrients implies a functioning organization including transport, quality control and interested users of the recycled nutrients.
The yearly cost for a single-family treatment system is around 10 000 SEK. The cost is lower when two or more households share a joint system. Connecting to the central treatment plant appears to be the most expensive alternative but also a package treatment system for one household may reach a yearly cost around 13 000 SEK.
Suggestions for a better sewage treatment in the area include upgrading of the existing systems and new systems. This report mainly focuses on the possibility to implement shared treatment facilities and such installations can be applied by at least five groups of households in the area.
The discussion section of this report gives the local authority advice on how to act when in contact with the house-owners and how to work to achieve better sewage treatment. |
| format | L3 |
| id | RepoSLU12734 |
| institution | Swedish University of Agricultural Sciences |
| language | swe Inglés |
| publishDate | 2005 |
| publishDateSort | 2005 |
| publisher | SLU/Dept. of Biometry and Engineering |
| publisherStr | SLU/Dept. of Biometry and Engineering |
| record_format | eprints |
| spelling | RepoSLU127342017-10-19T11:59:16Z Bättre enskilda avlopp i Sigtuna kommun : möjligheter för bebyggelse i Odensala socken Improved on-site sanitation in Sigtuna municipality : possibilities for settlements in Odensala parish Hårsmar, David enskilda avlopp enskilda avlopp There are around 855 000 on-site sewage systems in Sweden and some 1 800 of these are located in the municipality of Sigtuna. The Sigtuna local authority has set the goal that all sewage systems with insufficient function should be improved before the end of year 2010. A malfunctioning on-site sewage system may cause three main problems: spreading of diseases, discharge of eutrophicating compounds and wastage of resources. The municipality strives to reduce these problems already at the stage of granting permits for installation of on site sanitation systems. The municipality has recently adopted new guidelines, which demands certain minimum reductions for different compounds. The guidelines also state that it is preferred that neighboring house-owners cooperate in jointly built and operated sewage systems and that the system should be able to recycle plant nutrients. Systems with infiltration to groundwater are accepted even though their function is hard to monitor. This report focus on a specific area within the municipality but the results and discussion are also relevant to other similar areas. There are 54 households in the selected area. These were sorted into four categories according to their circumstances. Around 40 % of the households in the area have a legal sewage system and infiltration to groundwater and filter beds are the most common systems. In this report package treatment systems and filter beds – combined with either chemical precipitation or urine separation are evaluated, as well as connection to a large sewage treatment plant. These systems are compared regarding expected reduction, recycling potential and economy. The systems studied ought to meet the reduction requirements set by the local authority, i.e. reduction of at least 50 % of the nitrogen and 90 % of both the phosphorus and oxygen demanding compounds. However, the reduction reported in different studies varies greatly between them and also between installations in the same study. A system with filter bed combined with chemical precipitation might have some difficulties to achieve the target concerning nitrogen removal while on the other hand urine separation might have problems to meet the target for phosphorus reduction. To connect to the municipality's sewage treatment works means that theoretically 19 % of the nitrogen and 86 % of the phosphorus can be recycled and both package treatment systems and chemical precipitation in combination with filter bed have similar recycling potentials. Systems with urine separation differ by greater potential to recycle nitrogen but smaller to recycle phosphorus. Achieving recycling of plant nutrients implies a functioning organization including transport, quality control and interested users of the recycled nutrients. The yearly cost for a single-family treatment system is around 10 000 SEK. The cost is lower when two or more households share a joint system. Connecting to the central treatment plant appears to be the most expensive alternative but also a package treatment system for one household may reach a yearly cost around 13 000 SEK. Suggestions for a better sewage treatment in the area include upgrading of the existing systems and new systems. This report mainly focuses on the possibility to implement shared treatment facilities and such installations can be applied by at least five groups of households in the area. The discussion section of this report gives the local authority advice on how to act when in contact with the house-owners and how to work to achieve better sewage treatment. Det finns ca 855 000 enskilda avlopp i Sverige. Cirka 1800 av dessa finns i Sigtuna kommun där kommunfullmäktige har som målsättning att alla enskilda avlopp med dålig reningsfunktion skall vara åtgärdade innan 31 december, 2010. Ett dåligt avloppssystem kan i huvudsak medföra tre problem: smittspridning, utsläpp av övergödande ämnen samt resursförbrukning. Kommunen vill i tillståndsprocessen försäkra sig om att dessa problem begränsas i så stor uträckning som möjligt då fastighetsägare väljer anläggning. Miljöbalken med tillhörande förordning ger kommunen rätt att ställa krav på fastighetsägarna. Sigtuna kommun har våren 2004 antagit nya riktlinjer för enskilda avlopp. Krav ställs på funktion och önskemål finns om samordnade (gemensamma) anläggningar och anläggningar som kan återföra växtnäring, så kallade kretsloppslösningar. Infiltrationsanläggningar godkänns trots att funktionen är svår att kontrollera. Denna rapport riktar in sig på ett specifikt område inom kommunen men resultat och diskussion kan också appliceras på liknande områden. På fastigheterna i det utvalda området finns totalt 54 hushåll som efter en inventering delades in i fyra kategorier utifrån förutsättningarna. Ca 40 % av hushållen i området har idag godkända avlopp och infiltrationsanläggningar och markbäddar är vanligast. I rapporten utvärderas minireningsverk och markbädd med antingen urinsortering eller kemfällning som komplement samt anslutning till kommunalt avlopp. Dessa system jämförs med varandra med avseende på förväntad reduktion, kretsloppspotential och ekonomi. De typlösningar som studerats bör kunna klara de krav på reduktion som Sigtuna kommun ställer, d.v.s. att minst 50 % av kvävet och minst 90 % av fosforn och de syreförbrukande ämnena reduceras. En genomgång av några andra gjorda undersökningar ger dock att variationen med avseende på reduktionsgrad är stor, både mellan olika studier och mellan anläggningar i samma studie. Rening i markbädd med kemfällning som komplement kan ha svårt att klara kravet på kvävereduktion medan markbädd med urinsortering inte helt säkert når upp till kravet på fosforreduktion. Anslutning till det kommunala avloppsnätet innebär att det teoretiskt är möjligt att återföra 19 % av kvävet och 86 % av fosforn. Minireningsverk och markbädd med kemfällning som komplement har båda liknande potential medan systemet med urinsortering skiljer sig genom sämre fosforpotential men klart bättre potential att återföra kväve än övriga system. Återföring av växtnäring förutsätter dock en fungerande organisation inbegripet transporter, kvalitetssäkring och intresserade användare. Den årliga kostnaden för enskilda anläggningar ligger kring 10 000 kr per hushåll. Kostnaden sjunker då flera hushåll delar på en anläggning. Att ansluta området till kommunalt avlopp ser ut att bli dyrast. Också minireningsverk kan dock i vissa fall nå upp till årskostnader kring 13 000 kr per hushåll. De förslag på åtgärder som ges omfattar uppgradering av gamla markbäddar och infiltrationsanläggningar, nya gemensamma anläggningar samt nya enskilda anläggningar. Fokus ligger i denna rapport på möjligheten till gemensamma anläggningar. Rapporten visar på att gemensamma anläggningar är möjliga i åtminstone fem fall. I diskussionen ges förslag på hur kommunen skall agera gentemot fastighetsägare och bedriva arbetet för att åstadkomma väl fungerande avlopp. SLU/Dept. of Biometry and Engineering 2005 L3 swe eng https://stud.epsilon.slu.se/12734/ |
| spellingShingle | enskilda avlopp enskilda avlopp Hårsmar, David Bättre enskilda avlopp i Sigtuna kommun : möjligheter för bebyggelse i Odensala socken |
| title | Bättre enskilda avlopp i Sigtuna kommun : möjligheter för bebyggelse i Odensala socken |
| title_full | Bättre enskilda avlopp i Sigtuna kommun : möjligheter för bebyggelse i Odensala socken |
| title_fullStr | Bättre enskilda avlopp i Sigtuna kommun : möjligheter för bebyggelse i Odensala socken |
| title_full_unstemmed | Bättre enskilda avlopp i Sigtuna kommun : möjligheter för bebyggelse i Odensala socken |
| title_short | Bättre enskilda avlopp i Sigtuna kommun : möjligheter för bebyggelse i Odensala socken |
| title_sort | bättre enskilda avlopp i sigtuna kommun : möjligheter för bebyggelse i odensala socken |
| topic | enskilda avlopp enskilda avlopp |