På Luleå Flygplats används urea som halkbekämpningsmedel eftersom det löser upp isbeläggningar genom att sänka vattnets fryspunkt. Urea finns naturligt i vattendrag och jordar som ett resultat av exkretion och nedbrytning i form av nukleinsyror och proteiner. Halterna är vanligtvis låga i det naturliga kretsloppet. Stora mängder urea tillförs i och med halkbekämpningen (145 ton säsongen 2009/2010). Urea består av 46 % kväve som förekommer som ammonium vars utsläpp kan leda till övergödning och kan vara giftig för organismer i höga halter.

Wastewater handling of private sewage systems has become an all increasing matter. In Stockholm region the 90 000 private sewage systems contribute with larger phosphorus flows to the Baltic Sea than the two biggest sewage plants in the area, Henriksdal and Käppala, contribute together, even though these two plants purify wastewater from more than one million inhabitants. When summer house areas turn into areas for permanent living ? transition areas ? the load on the existing systems increases, systems that already often are unsatisfying. In those areas it is not clear what the best system choice is; On-site systems for single households; Local collective systems or Connection to central systems.

The access to good sanitary facilities is an important factor that elevates the experienced living standard as it improves hygiene and reduces the transmission of deseases. The ratification of the millennium goals by 189 countries demonstrates that this is an important international issue. Together the countries have taken upon themselves that the proportion of the population that lacked access to sustainable safe drinking water and sanitary facilities in the year 2000 will have been reduced by half by the year 2015. In Peru, the construction of sewage pipe networks to transport the sewage out of the direct human environment is progressing. The safety and sustainability of these systems can be questioned, since in Peru the sewage seldom receive any treatment before being emitted to a Recipient. This is taking place in Picota and sorrunding villages as well. In the last 25 years several systems implementing small-scale onsite treatment have been introduced throughout Latin America in an attempt to give more people access to sustainable and safe sanitary facilities, reducing water consumption and taking advantage of the agricultural values of the sewage fractions while protecting the environment from its negative impact. In this study three different sanitary systems and the effects of different population growths were compared.

Stormwater is surface runoff water that originates from precipitation or snowmelt and that on hardened surfaces prevents to infiltrate the ground. In city areas stormwater can consists of major amounts pollutants and when reaching a lake or watercourse it can cause damages on vegetation and animals. Therefore it is important to treat polluted stormwater before it reaches the Recipient. The municipality of Örebro have since the 90ies an extensive work with treatment of stormwater in sedimentation ponds. A new stormwater treatment project is planned in an industrial estate in Skebäck, Örebro.

Ala Lombolo i centrala Kiruna har under ett drygt sekel påverkats av mänsklig aktivitet, vilket har resulterat i att sjön idag är kraftigt förorenad. Huvuddelen av föroreningarna återfinns fastlagda i bottensedimenten och läckaget från sjön är relativt litet i jämförelse med de lagrade metallkvantiteterna. Förändringar av rådande förhållanden i sjön kan medföra att föroreningarna mobiliseras och sprids, bl.a. till Torneälven. Syftet med detta examensarbete är att identifiera kvalitativa förändringar och efterföljande konsekvenser som kan beröra Ala Lombolo i framtiden.