In connection with the admittance of the EC-directive (99/31/EC) in Swedish politic, through the constitution of waste depositing (2001:512) at year 2001, the rules about management the landfills and leachates tightened. At the landfill Vissberga in the municipality of Hallsberg, a leachate treatment plant was constructed just a year thereafter. This treatment plant consisted of an aerated pond with a following land treatment and a willow cultivation to replace the land treatment during the summer. In this case the parameters, which were estimated as the most important to reduce, were iron and nitrogen. The iron would react with the oxygen-rich water in the aerated pond and precipitate to ferric-hydroxide and than settle in a calm zone of the pond. The rest of it would be reduced by filtration in the land treatment. The elimination of nitrogen would happened by two biological processes. The first one was intended to be in the aerated pond, where ammonium ions would oxidise to nitrate by the process called nitrification. The established nitrate would then be transformed to nitrogen gas by a denitrification in the land treatment and be emitted to the air. Unfortunately the reduction has not been desirable, why the main objective of this thesis is to quantify the problem and identify the limitations of the plant by describing the processes involved and find out which factors that affects them, in particular the impact of the temperature. This was executed by a literature study about the processes and by studying results from analysis that were obtained both from earlier samples and from samples which were done during this thesis. At the end it appears that the plant was overloaded and that this probably depends on incorrect estimates of the leachate water flow, done during the dimensioning of the plant. Due to the high flow the ferric-hydroxide can’t be settled and the nitrifyers don’t have enough time to reduce the nitrate. One part of the objective was to found out in which degradation phase the landfill are for the moment, to see what changes is to expect in the combination of the leachate water in the future. However, it was difficult to say with certainty, due to the circumstances that the landfill currently is in the methane phase and the knowledge of the next phase, the humic phase, is very limited because very few landfills has now days reached this phase. The phase determination was made by comparisons between composition of the leachate water of Vissberga and leachate water from the literature. An interview study was also done during this thesis, where people from the Counties Agency in the county of Örebro and Västmanland, the municipality of Uppsala and the Environmental Protection Agency were attended. The question was: Which new requirements that might be claimed at leachate water treatment in a foreseeable future?

”Rätt avlopp på rätt plats” – Livscykelanalys av tre enskilda avloppsanläggningar Problemen med övergödning i Östersjön och i Sveriges insjöar är stort och enskildaavlopp pekas ut som en central aktör, framförallt beträffande fosforutsläppen. I Sverigefinns det ungefär en miljon enskilda avloppssystem och nästan hälften av dessa har enså pass bristande vattenrening att de inte uppfyller gällande lagstiftning. Utvecklingenav nya tekniker för rening av avloppsvatten har länge strävat efter att minska utsläppenav övergödande ämnen, detta ibland på bekostnad av andra utsläpp, så somväxthusgaser och försurande ämnen.Det här examensarbetet har därför med hjälp av metodik från livscykelanalys (LCA)utvärderat tre enskilda avloppssystem med tanke på deras utsläpp av växthusgaser,försurande gaser samt övergödande ämnen. Då misstanke också fanns att de lokalaplatsegenskaperna påverkar de enskilda avloppssystemens totala miljöpåverkan,utfördes även en intervjustudie med ett antal av landets kommuner. I intervjustudiengjordes ett försök att identifiera de platsegenskaper som påverkar valet ochutformningen av de enskilda avloppssystemen. De tre avloppssystemen som ingick istudien är markbädd samt kompaktfilter i kombination med antingen ett reaktivt filtermed Polonite®, eller i kombination med kemfällning.Resultatet av studien visade att markbädden hade lägst utsläpp av både växthusgaseroch försurande gaser, men högst utsläpp av övergödande ämnen. De tvåfosforreducerande systemen uppvisade betydlig bättre potential för att reduceraövergödande ämnen, men detta på bekostnad av större utsläpp av växthusgaser ochförsurande gaser, speciellt i fallet med det reaktiva filtersystemet. Lokalaplatsegenskaper, så som näringsretention, visade sig spela en central roll för deundersökta avloppssystemens totala miljöpåverkan. I områden med hög fosforretentionunder vattnets väg till havet skulle avloppssystem med höga utsläpp av fosfor (så somdet markbaserade systemet) kunna vara försvarbara. På de platser i landet därövergödningen är problematisk finns det dock motiv för att använda fosforreducerandesystem. / "Right sewage system in the right place" - Life cycle assessment of three on-sitewastewater treatment options The problem with eutrophication in the Baltic Sea and in Swedish lakes is serious andon-site wastewater treatment systems are considered important, especially forphosphorus emissions. There exist about one million on-site wastewater treatmentsystems in Sweden and almost half of them do not meet current legislation.Development of new technologies for on-site wastewater treatment systems has for along time been focused on reducing emissions of eutrophying substances. However,there is a risk that this reduction could be achieved at the expense of other emissions,such as greenhouse gases and acidifying substances.This master thesis has therefore by use of life cycle assessment (LCA) evaluated threeon-site wastewater treatment systems considering their total emission of greenhousegases, acidifying gases and eutrophying substances. Because local site characteristicswere thought to affect the sewage systems overall environmental impact, an interviewstudy were also carried out with a number of municipal officials. The interview studywas designed to identify the local site characteristics that influence the selection anddesign of the on-site wastewater treatment systems. The three sewage systems includedin the study were a soil treatment system with surface water discharge and a compactbiological filter in combination with either a reactive filter module with Polonite®, or incombination with chemical precipitation.The results of the study reveal that the soil treatment system had the lowest emissions ofboth greenhouse gases and acidifying gases, but the largest emissions of eutrophyingsubstances. The two phosphorus reducing systems showed significantly greaterpotential to reduce the emissions of eutrophying substances, but at the expense of largeremissions of greenhouse gases and acidifying gases, especially in the case of thereactive filter system. Local site characteristics such as the retention of nutrients, provedto play a vital role in the investigated sewage systems overall environmental impact. Inareas with high retention of phosphorus sewage systems with high emissions ofphosphorus (such as the soil treatment system) where favored. However, in areas whereeutrophication is problematic, it is justified to use phosphorus reducing systems.