Blue line metro extension in Stockholm rated ‘Excellent’

People and communities

In the project the client has from early planning stage throughout the design worked with several activities to involve the community. There have been several public meetings, open houses, digital surveys, attitude surveys etc.

When it comes to design one of the entrance halls has been designed with a meadow roof and the ventilation tower has been designed with integrated bird nests which enhance the recreational value. The platforms have also been designed as a part of the Stockholm Metro art exhibition which also make them feel safer for different groups.

A separate Social Impact Assessment has been conducted as well as studies about child perspective in the construction stage and Traffic Safety Analysis.

Land use and landscape

Prior to choosing the location of the metro a location study was conducted, both for location of stations and location of the tracks. The aspects that were included in the study were:

• Other projects in the area

• Existing structures

• Municipalities’ detailed development plan

• Geological conditions

• Track technical conditions

• Availability/accessibility

• Existing pipes and cables

• Protected areas/national interests

• Environmental conditions 

The project is located partly in an urban area and partly on a field. The western part of the field will be developed to an urban area including the metro’s entrances, while the eastern part of the field, close to the creek, will be preserved as a nature reserve. Since the metro is located below ground with only one separate entrance hall (the rest integrated in buildings to be built) the impact on land use and landscape is relatively small.

During the construction stage, most of the areas used for establishment and temporary works were chosen because they were already paved surfaces.

There were some contaminations that are being removed through the excavation and there are also some kerosene and PAH:s present that are been remediated on site.

Ecology and biodiversity

Two environmental impact assessments and several underlying studies were conducted. A couple of protected species were found nearby the project site:

• Eurasian skylark

• Meadow pipit

• Amphibians

• Hepatica

• Pasqueflower 

Stone loach was also found in a nearby creek. However the species were found much further down the creek and stone loach is not protected, only uncommon.

Since most part of the project is located below ground, it will have very small impact on the ecology and no protective measures was deemed needed in the EIA:s other than measures to minimise the ground water lowering.

To compensate for the small areas that are being built above ground, the roof of the separate entrance hall is a meadow and the ventilation tower is made in wood as a big bird nest.

The water environment

Protective measures were taken to prevent a lowering of the ground water due to the tunnelling. Grouting was done regularly during construction and there was also infiltration equipment prepared to keep the ground water levels stable, both during construction and operation.

During construction stage there were very high demands of waste water treatment and control measures are in place. Both stormwater and water from the process are undergoing treatment before discharge.

During operation there is a permanent water treatment plant in place for the drainage water. Drainage water can be led to infiltration wells and be used as refill groundwater.

Since the project is below ground there are very little hard surfaces that lead to runoff and the only separate building will have a green meadow roof that can delay/retain runoff.

Stations were fitted with water efficient faucets.

Physical resources use and management

Together with the municipality, the project signed a contract saying that if the municipality put a local rock crushing plant in the area, the project had to transport all their rock there and later re-buy from the same crushing plant to minimise transportation. The crushed material can also be used in the extensive exploitation in the local area.

In the project the construction material evaluation system Byggvarubedömningen has been used. The system evaluates specific products in three different levels (avoid, accepted, recommended). The aspects evaluated for each product are among other aspects hazardous chemical components, percentage renewable content, percentage reused material, FSC/PEFC, emissions, percentage renewable energy during manufacturing, packaging method, VOC etc.

The project was been designed with a long lifespan (120 years) to minimise waste during construction. Several energy saving designs has been made, such as placing platforms on a little “hill”, LED-lightning and energy efficient escalators/elevators.

The historic environment

There were some areas of archaeological value identified. The project's location was changed to avoid crossing these. Hence there has been little to no impact in the historic environment from the project where it is located in a tunnel below ground. The ventilation tower has been made rounded in wood to better fit in the landscape.

The entrances will affect the feeling of the historic environment and landscape in the area, however the future development of the Barkarbystaden will affect it more which is outside the project scope.

Transport

The project itself is a transport project made to enable more sustainable transportation’s between Stockholm and Barkarby.

There have been transportation policies in place during design stage and we have followed up on them with a transportation survey with results showing that a lot of meetings were made over Skype and that most project members used bike, bus or metro to travel to their offices and between meetings.

In the design stage there has also been a separate Traffic Safety Analysis made for the construction stage and the local crushing plant reduces the length of the transportation’s.