Blue line to Barkarby Access tunnel Robothöjden-Landningsbanan

CEEQUAL Excellent Sustainability rating (81.4%) – Whole Team Award
Version 5, December 2020 | Stockholm, Sweden

Assessor: Elin Hedlén, Tyréns
Verifier:  Ric Collinson, Atkins
Designers: Tyréns, Ramboll, White Arkitekter
Client: Administration for Extended Metro, Region Stockholm
Constructor: NCC Sverige AB

Project Summary

The contract includes the construction of two access tunnels and consists mainly of sheet piling, soil and rock excavation, rock shaft, rock reinforcement/sealing by grouting in tunnels, rock cutting and vertical shaft. The tunnels will be used as access tunnels for the following main tunnel contractor and as a service tunnel after the project is completed.

Earthworks and water and sewerage work is included as well as concrete work for the superstructure for the vertical shaft, which will be a future shaft for supply air. Fences and gates have been set up around the work areas. Also some temporary installations is included that is to be left behind for following contracts, such as ventilation, electricity and water/sewerage.

An environmental permit which regulates all the critical activities that may interact with the surrounding environment during the construction phase, is the backbone of the environmental protection work in the project.

Achievements

Project Management

The contractor put together a project specific sustainability management plan that gave the strategies and plans for all aspects of sustainability. The plan consisted of an introduction, purpose and application, information about the project, management of sustainability aspects, risks and opportunities, report and follow up, communication, effects on third party among other things.

In the Management of sustainability aspects chapter, each aspect was described, had a goal, listed measures to reach the goal and how to follow up and report them and who was responsible for each part.

The aspects evaluated were:

5.1 Groundwater impact
5.2 Usage of water
5.3 Discharge to water
5.4 Noise and vibrations
5.5 Mass management plan and management of contaminations
5.6 Waste
5.7 Climate impact and energy
5.8 Hazardous substances in chemicals and built in materials
5.9 Vehicles and machinery
5.10 Air pollution
5.11 Nature, cultural history and remains
5.12 Landscape and ecology
5.13 Traffic and transports
5.14 Social responsibility in supply chain

People and Communities

During construction stage there has been several ways for the community to leave comments, such as through customer service, mailbox, open houses (some postponed due to covid), information stands at municipality days/markets.

Every year there has been an attitude survey conducted and newsletters has been sent out.

Before each blast text messages has been sent out and information video for kids has been produced and shared.

There is also a separate project website, a facebook page and linkedin.

Through the legal process there is also an environmental permit that regulates how aspects that can affect nearby residents must be managed and controlled, such as noise and vibration and water management.

Land Use and Landscape

In the project, existing hard surfaces (eg the airfield) have been reused when possible.

Contaminated masses have been handled according to the permit as described in the projects mass management plan.

In the project, storm water, process water and water leaking in the existing tunnel in Robothöjden and new tunnels had to be handled. Contaminants were found, such as residues from explosives, minerals from soil and rock in the form of suspended material, oil leaks from existing contaminants of PAH in asphalt or PFOS from previous military activity in the area. Treated water was led to spillage, recipient or was infiltrated on site.

During production, the treatment system has been gradually expanded both in terms of capacity to handle water volume but also in terms of the type of pollution to meet current guideline values. To lower the pH, Linde Gas was contacted, who assisted with support and equipment regarding pH regulation. Together with Envytech Solutions AB, the treatment systems have been evaluated and expanded to meet the treatment requirements.

For example, PFOS was detected in leaking tunnel water, which has been treated by supplementing with a buffer tank, 2 lamella containers, 2 bag filters, 1 sand filter and 2 filters with activated carbon. Other parameters that needed to be handled were elevated suspended content and hexavalent chromium. For purification of hexavalent chromium, tests have been carried out by client together with the Swedish Transport Administration.

Outgoing water from the runway contained too high levels of suspended material, so flocculants were added to reduce the amount of fine particles in outgoing drainage water. An alternative was centrifugation, but due to a great need for supervision and long delivery times, that alternative was rejected. Different flocculants were also evaluated, and the least pH sensitive agent was selected.

The Water Environment

A control program is in place according to the environmental permit.

Drainage water is checked and measured continuously, and an extensive water treatment plant was put in place.

To prevent any oil spills from reaching watercourses, filling stations have been built with embankments, only double-jacketed tanks were allowed within the workplace area, and absorbents must be present in all machines. During environmental and protection rounds, it is checked that everything is in order. Any deviations are handled in the project portal where measures and the person responsible for the measure are reported.

Collected stormwater and drainage water was reused for watering blasts in the tunnel.

Leaking groundwater from Landningsbanan was collected, treated and diverted to equalization reservoirs to maintain groundwater levels and the water level in Igelbäcken, but it was never needed during the contract.

Physical Resources – Use and Management (Energy, Water, Materials, Waste)

Early in the project a workshop was held.

The workshop evaluated:

  • Water efficiency
  • Energy efficiency
  • Resources
  • Waste
  • Climate impact

The identified measures were listed in a resource plan where they were followed up.

Climate impact was calculated quarterly and project specific EPDs for asphalt, reinforcement, construction cement, concrete and sheet piling were used. The climate impact was reduced by about 1400 tonnes of CO2-eq compared to estimated in design stage.

Two big measures made was the change to HVO fuel and use of recycled sheet piling.

There was a separate mass management plan put together. Products have been environmentally (and health) evaluated through Swedish system ”BVB” where they are also logged with information about the products, such as recycled content and waste management for the products.

Energy from renewable sources has been used in the project and parts of the fuel are from renewable sources with lower carbon dioxide emissions (HVO).

Suppliers are assessed regarding social sustainability (how large amount will be used, whether the material contains risk material and whether the material comes from a risk country).

Locally placed crushing plant has been put in place (agreement between client and municipality). This has been used for excavated masses and to buy back bulk fill.

Leftover facility-specific material such as cement, bolt, beams, drive plates, lighters, cables, etc. are reused in future projects. In Frövi there is a warehouse for the material. For example, black bolt has been delivered from the Norvik project to Barkarby, cables have been picked up from Frövi and sheet piling has been picked up from Veddesta.

Transport

The Sustainability Plan contains an assessment of possible transport alternatives to the project. Transport by boat, train and plane has been briefly described. The products purchased for the project are transported differently depending on where they come from, and boats or trains are most likely used for parts of the route during long transports of heavy material (eg sheet piling). The last part of the transport to the project, however, takes place by truck because there is no other possibility to reach the project site.

The procurement requirements describe which modes of transport that have been procured for the project.

Information about how to best travel to and from the project site have been shared with the workforce.

Challenges

Management of water to meet the requirments in the environmental permit (PFOS, chrome, particles) and reuse of water due to a lot of suspended particles and pH.

Local water treatment plant was put in place to treat the different contaminations and continuous testing of water quality.

The project stored the soil masses on site hoping it could be reused in a project nearby, but due to time plan in the two projects it wasn’t possible to keep the masses for the time needed. So the masses had to be sent to a soil treatment plant 30km away instead of 3km.

What were the drivers and perceived benefits for undertaking a CEEQUAL assessment on this project?

A receipt on doing the right things measured on an international level, concrete way of showing environmental work. Motivation is branding and communication. The client had bonus related to CEEQUAL that gave financial returns.

The client’s drivers was primarily to use Ceequal as a tool to constantly improve the environmental and sustainability work and to increase its sustainability standard between each contract.

How did the use of CEEQUAL influence the outcomes of the project? What was done differently because of the CEEQUAL process?

More discussions in the project group about sustainability which lead to a better understanding and higher knowledge within the project.