Blue line to Barkarby Access tunnel Veddesta

CEEQUAL Excellent (81.9%) – 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: SBT Sverige AB

Project Summary

The contract is mainly soil excavation, rock excavation, rock reinforcement and sealing by grouting for tunnels as well as earthwork and water /sewerage work:

  • Execution of one tunnel in rock
  • Rock tunnel will be used as a working tunnel for 4713 Main tunnel contractor and as a service tunnel after the project is completed
  • Open cut is about 120m long
  • Rock tunnel about 235 m long
  • Cross tunnel of about 30 m long is also included

Fence and gates must also be set up around the work area.

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 and report and follow up.

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:
4.1 Groundwater impact
4.2 Noise
4.3 Vibration
4.4 Discharge to water
4.5 Chemical products
4.6 Built in products
4.7 Resources and climate impact
4.8 Waste management
4.9 Socially sustainable product chains
4.10 Air pollution
4.11 Dust and clean work site
4.12 Nature, historic environment and remains

The contractor was also certified according to ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018

People and Communities

During construction stage there has been several ways for the community to leave comments, such as through costumer 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

The construction site and the tunnel starts at a previous industrial site.

All openings can withstand 100-year rain with a climate factor of 1.2 without damaging the facility.

Delay reservoir must be 12 m3 to withstand a 100-year rain. The reservoir is now 30 m3 and thus, with margin, large enough to cope with surface water runoff.

Environmental permit regulates how contaminated soil is to be handled, which is strictly followed in the project.

The Water Environment

A water budget has been drawn up, calculating how much water that is assumed to be used in different processes.

A control program is in place according to environmental permit and drainage water is checked and measured continuously.

The project is not adding any hard surfaces that lead to more runoff and rainwater water has been reused for blasting/dust management.

Water treatment plant was also put in place (see red square).

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

Early in the project a workshop was held.

The workshop evaluated:

Water efficiency

  • Water in materials
  • Water during construction
  • Water during operation

Energy efficiency

  • From transports
  • From construction
  • From operation

Resources

  • Optimization
  • Material choice
  • Reuse

Waste

  • Reuse/recycle
  • Reduce through construction process
  • Operation

Climate impact

  • Material choice
  • Construction process
  • Operation

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

Climate impact was reduced by about 200 tonnes of CO2-eq compared to design.

Changed recipe for grout was the biggest measure made.

More tunnel was excavated than was decided in design so reduction % is actually bigger than it shows.

With the client’s formula for calculation % the reduction was about 16%.

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.

100% wind power through green contracts and 100% HVO (Hydrogenated vegetable oil).

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.

Supplier of concrete, gravel, wood and asphalt have been chosen based on distance to project place. Steel from Swedish suppliers.

0% waste was sent to landfill.

Transport

Supplier of concrete, gravel, wood and asphalt have been chosen based on distance to project place. Steel from Swedish suppliers.

Unloading has taken place at night to reduce the environmental impact, especially with regard to traffic congestion on the local streets.

100% HVO and environmental requirements on the fleet.

Train and boat transports are not possible to the project due to the location of the project. Therefore, the project makes the best of the situation and tries to use the trucks as resource efficiently as possible. For example, both explosives and grouting cement are delivered on delivery rounds where the supplier collects several deliveries within the same area and coordinates these.

Challenges

The neighbours (industries) were affected during first part of work when a lot was made above ground. -> contractor had an open dialogue with them about how long the project was going to take and they were invited to a site visit to better understand the project.

A lot of transports of masses through residential areas -> Night transports to limit the amount of traffic during rush hours. Local crushing plant to reduce transport route.

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 and the client´s bonus.

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

What elements of this project highlight best practice and innovation?

Manual ventilation in tunnel so it could be changed after needs to reduce energy use.