Environmental issues are a priority at Swedavia, and Stockholm Arlanda Airport works continuously in a number of different areas to reduce its environmental impact.
Our zero vision
In 2020, Swedavia achieved the company’s goal of no fossil carbon dioxide emissions from airport operations run under our own management.
Extensive work underpins our success in achieving zero fossil carbon dioxide emissions. We purchase green electricity for all our operations, the back-up power supply runs on hydrotreated vegetable oil (HVO), our vehicle fleet runs on HVO, fossil-free gas or green electricity, and we purchase liquefied petroleum gas (biogasol) and biogas.
Read more about our zero vision work, what else we do and what you can do to contribute to the transition to net-zero aviation.
Expanded climate work
All of Swedavia’s airports are accredited at the ACA 3+ level in accordance with Airport Council International (ACI) Europe’s standards for the climate work of airports. That means our airports continuously reduce fossil carbon dioxide emissions from their own operations, offset the emissions that have not yet been reduced and help other businesses operating at the airports to reduce their emissions. At the end of 2020, we achieved our fossil carbon dioxide emissions goal for airport operations run under our own management.
The next goal is to have all the airports accredited at the ACA 4+ level, which means that compounds to de-ice runways/aircraft and coolants are to be included in the measurements. We shall also work to a greater extent to engage and work together with other companies and organisations that have significant carbon dioxide emissions at the airports in order to continue reducing emissions together. Over time, all the operations at our airports will switch to renewable energy sources. This work is in line with the International Panel on Climate Change’s goal not to exceed a 1.5 C degree rise in global warming as well as Swedavia’s strategy and goals for proactive climate change adaptation.
You can read more about the programme here.
The world’s largest energy storage unit – the Arlanda aquifer
In the summer of 2009, Arlanda inaugurated the world’s largest energy storage unit, an aquifer located in the Brunkeberg Ridge at the airport. The aquifer is a natural underground groundwater reservoir that helps cool/warm the airport depending on the time of year. Thanks to the aquifer, we can save energy equivalent to the amount needed to heat and cool 2,000 single-family homes.
Air, ground and water
Many rare plant and animal species, even from a European perspective, can be found in the area around the airport. This area is also an interesting cultural landscape, with 18th century buildings, rune stones and Iron Age burial grounds.
Pastureland in the hamlet of Lejden, east of the airport, is one example of an area with natural conservation value. Animals have grazed in Lejden’s meadows since the Iron Age, and the flora there today include a number of species on the EU Red List of threatened species. Field gentian (Gentianella campestris ssp. fennica) and eyebright (Euphrasia rostkoviana var. campestris ) are two plants under great threat that are found in Lejden.
Lejden is a nature conservation area, created in 2009 by Swedavia in partnership with its tenant, the Municipality of Sigtuna, the County Administrative Board and the World Wildlife Fund.
(Reports in Swedish)
Biologisk mångfald på Arlanda 2013 - PDF, 2 MB
Inventeringsrapport Lejden 2012 – PDF, 2 MB
Naturinventering – PDF, 92 KB
Inventering Finnögontröst – PDF, 3 MB
Vad flyger på Arlanda? – PDF, 99 KB
Svampinventering Åsbarrskogar – PDF, 75 KB
Concentrations of air pollutants at Arlanda correspond to levels found in a mid-sized Swedish metropolitan area.
Measurements of air pollutants have been taken at Arlanda since 1994, and the results show, among other things, that:
- amounts of sulphur and nitrogen in precipitation (which contribute to acidification) per area unit at Arlanda are not higher than the average for Stockholm County.
- firs and pines at Arlanda lose needles to roughly the same extent as the average for trees in Stockholm County.
- concentrations of pollutants are greatest at the terminals and on the roads with the heaviest volume of vehicular traffic.
How air pollutants are spread depends in part on wind direction, wind speed and temperature. It is thus difficult to give an answer for what percentage of emissions affects the different areas.
Emissions from air traffic
Aircraft engines produce the same kinds of emissions generated in the combustion of all fossil fuels: carbon dioxide, nitrogen oxides, hydrocarbons, soot, particulate matter, carbon monoxide and sulphur dioxide.
Sometimes the air at the airport may smell strongly of jet kerosene. What makes it smell like kerosene is sulphur compounds, known as mercaptans, which have a penetrating, intense and characteristic smell in very small concentrations.
Sulphur compounds belong to the same group of substances that create odour problems in conjunction with paper pulp production (using the sulphate process). Mercaptans are not toxic in the low concentrations found at Arlanda.
One way to reduce atmospheric emissions is by encouraging airlines to use modern aircraft, which are better for the environment – take-off charges are lower the cleaner an aircraft’s engines are. The aim is to get airlines with older planes or older aircraft engines to switch to more environmentally-friendly alternatives.
The aircraft’s whirlwinds are not fuel dumping
All aircraft leave whirlwinds in their wake. When the weather is humid, the whirlwinds are visible since condensation is formed from water steam in the air. It may sometimes look like the aircraft is releasing fuel as it lands. 'Vortex is another term for the whirlwinds trailing the aircraft.
Aircraft very rarely dump fuel and only in an emergency, when a fully fuelled plane needs to make an emergency landing. Only the largest aircraft have the ability to dump fuel. If fuel needs to be dumped, this should take place over water and at an altitude high enough to enable the fuel to be converted into steam before it reaches the earth.
De-icing of aircraft and runways
Aircraft are de-iced with propylene glycol, and runways are treated with potassium formate to prevent skidding. Potassium formate is a kind of salt and is used instead of urea today since its nitrogen concentration is much lower.
Propylene glycol and potassium formate as such have low toxicity levels and break down easily in nature. But this breakdown requires a great deal of oxygen, so the compounds can cause oxygen depletion in waterways and groundwater if large quantities are released. In order to have as small an impact on the water around Arlanda as possible, a number of measures are carried out.
Glycol fluid is recycled after the aircraft’s de-icing
De-icing is only allowed in areas with a special glycol recovery system. As much glycol fluid as possible still on the ground once an aircraft has been de-iced is suctioned up by glycol recovery vehicles.
Given its relatively high concentration of glycol, the fluid is recycled. The fluid collected is treated and concentrated into new, pure glycol at the Vilokan facility at Arlanda.
Fluid with a relatively low glycol concentration not suctioned up runs into the glycol recovery system and is then soon pumped to the Käppala treatment facility.
Most chemical breakdown takes place in the airport’s treatment facility
Formate from runway anti-skid treatment and glycol that drips off taxiing aircraft end up in the surface water from the runways and aprons. Most of this is conveyed to surface water treatment facilities, where the chemicals are broken down using biological processes. This is done largely in the airport’s treatment facilities before the water is released into waterways.
Samples show improvements in the Märsta river
The water quality of the Märsta river has improved recently, in part as a result of Arlanda’s measures to reduce the impact on this waterway. The catchment area for the Märsta river includes the town of Märsta, a number of companies, farms and the airport, all of which have an impact on the waterway.
The water quality of the Märsta river has improved over the last few decades, and in the latest assessment the river was classified as having “moderate ecological status” and “does not achieve good chemical surface water status” based on the assessment criteria of the EU Water Framework Directive.
200,000 square metres of membrane protect the groundwater around Runway 3
Runway 3 extends in part over a ridge of stratified sand and gravel that holds groundwater, so it is especially important that glycol and salt residues do not reach it. This was also a high priority when the runway was built. Runway water therefore runs down into drains along the runway and is then conveyed to a retention basin, where it is treated if necessary.
A 1.5 millimetre thick water-impermeable membrane has been laid at a depth of 1–2 metres in the area around the ridge. This allows the water along the runway to be conveyed to the runway’s treatment system. A total of 200,000 square metres of membrane have been laid out around Runway 3, which is equivalent to the area covered by 28 football pitches.
Swedavia’s goal is to work so that the noise load around Arlanda is considered acceptable relative to the social benefits of aviation and the airport. We make regular noise assessments and measurements to ensure that we are within the scope of our environmental permit.
Swedavia’s work to reduce the impact of noise from Arlanda entails, among other measures, insulating homes close to the airport to reduce noise and giving preferred treatment to airlines that use aircraft which produce less noise.
To the extent possible, Swedavia tries to ensure that flight paths are routed around densely populated areas. To reduce noise and atmospheric emissions, Swedavia also works to increase the number of curved approaches at Arlanda.
Using a curved approach, aircraft can avoid flying over densely populated areas in their approach. Trials using curved approaches are being conducted at a number of Swedavia’s airports. To carry out curved approaches, approval is needed from the Swedish Transport Agency for the airline, the individual aircraft and its crew.
Swedavia also works with green approaches – read more here.
Open dialogue and increased environmental awareness
Along with steps to limit noise, measurements are taken and test flights are performed, and there is also a programme for air traffic controllers and pilots to further raise environmental awareness. An open dialogue with Arlanda’s neighbours is also an important part of the work, and the airport strives to plan departure and approach routes so that the noise disrupts as little as possible and is as low as possible. Homes subjected to the most noise have been sound-insulated.
The environmental conditions specify, among other things, that the approaches to Runway 3 from the south in heavy traffic which were then in effect could also continue after January 1, 2018.
However, approach procedures that avoid the densely populated area of Upplands Väsby must be used when this is possible, as long as it does not affect the airport’s capacity and takes into consideration regulations, air traffic control management, aviation safety and weather conditions.
Read more here (in Swedish):
Ansökan i kort version – PDF, 661 KB
Miljökonsekvensbeskrivning, sammanfattning – PDF, 352 KB
Populärversion – Arlandas framtid påverkar Stockholms och Sveriges utveckling - PDF, 6 MB
Populärversion – Handlingsplan för att minska flygbullret över Upplands Väsby – PDF, 153 KB
Presentationer från huvudförhandlingen
Mark- och överdomstolens dom 21 november 2014 – PDF, 2,8 MB
Mark- och miljödomstolgens dom 17 maj 2017
Environmental report (in Swedish)
For information about aircraft movements, Swedavia currently suggests that those interested use public tools such as Flightradar24.com.
The Webtrak tool that we previously made available here on our website is being reviewed, and we are exploring the possibilities of using other data sources. This is in order to once again enable people living in the vicinity of our airports to track air traffic movements and link this information to aviation noise measurements where available.