[10/21/2005]
Project given Sweden’s most rigorous environmental examination
Seven months after construction started, the Citytunnel has made its mark on Malmö city, both in the city itself and in the southern suburbs. The tunnel, which it is estimated will cost SEK 9.45 billion, is the single largest construction project ever carried out in Malmö. The Citytunnel is also the most extensive environmental case ever handled by the Environmental Court in Växjö.
In December last year, the Environmental Court gave the go-ahead for the majority of the project. The extensive judgement involved hundreds of specific restrictions and requirements, affecting, eg, groundwater treatment, water purification, air pollution, noise, and vibration.
Press conference
On Friday, the Citytunnel project held a press conference covering the environmental aspects of the construction sites at Malmö Central Station, the existing rock cavern station at Triangeln, and at Holma where the tunnel comes to the surface and a station will be constructed near the abutment of the Öresund Bridge.
The press conference was attended by Project Manager Örjan Larsson, Environmental Function Manager Wollmar Hintze, Environmental Co-ordinator Åsa Berger Hallbergson, and the three Sub-Project Leaders, Rolf Dahl, Patrik Magnusson and Michael Myhré.
Most extensive inspection ever
Great efforts have already been made to minimise the environmental effects of the tunnel.
One of the major concerns of the inhabitants of Malmö before the project was that lowering the water table and vibrations from tunnel boring would cause subsidence and cracking in the old buildings of the city centre. This became subject to the extensive consultations that preceded environmental testing.
‘To minimise risks and keep checks, more than 1,200 settling studs were set up around central Malmö, forming measurement points that will be checked regularly during and after the construction period. This is the most extensive inspection of its type ever carried out in Sweden and probably in the whole world’, claims Wollmar Hintze.
Harbour converted to purification plant
Water treatment includes a number of different processes. For example, the innermost part of the Inner Harbour at Skeppsbron, where the main Citytunnel station will be built 20 m below ground, will be converted to a purification plant where concrete residues and other contaminants are removed from waste water before it is allowed to pass into the Öresund. Separation is an important measure to protect fish and other marine life.
In southern Hyllie, near the town of Vintrie, special filter and compensation basins will be built as permanent dams. In the area around the tunnel mouth, it is necessary to lower the groundwater level. Some 90% of the water pumped away via 35 drains (300 m3 per hour) will be re-injected into limestone via another 45 drains further from the track area. This is to ensure that lowering the groundwater table will not affect the surrounding landscape.
Similar re-injection of groundwater will take place around Triangeln Station. Also, the older trees around St Johannes Church will be saved through a number of different protective measures, including soil backfilling and irrigation.
Exhaust-gas cleaning
Several of the environmental protection measures are unique among Swedish construction projects. They apply, for example, to the special exhaust-gas cleaning equipment with which all excavation and other petrol or diesel powered vehicles and machinery working in the harbour area have been fitted. Continuous air-quality measurements show that emissions are now well within the limits set by the Environmental Court.
Clean vehicles for clean roads
Considerable amounts of waste material have to be removed from excavations and drilling. This has to be carried on heavy trucks through central Malmö, mainly for tipping in the lagoon at Malmö port. Excavated material therefore contributes to the ongoing extension of the port.
To avoid heavy-vehicle traffic polluting the urban environment, every worksite is provided with automatic vehicle cleaning stations that wash the vehicle’s wheels and underside.
Of course, some disturbance cannot be avoided in such an extensive construction project being carried out right in the heart of the city.
Project Leader Rolf Dahl believes that the centuries-old infrastructure around both Malmö Central Station and Triangeln involves a literal ‘can of worms’ in terms of cables and conduits. Often, these are wrongly indicated on municipal maps, and it is not infrequently the case that landowners are not even aware of their existence.
Some electricity, gas, and water mains have therefore been accidentally dug up. Obviously, it is necessary that all underground leads are cleared away and new ones laid before excavation work can begin in earnest.
Ongoing dialogue with Malmö citizens
The years of planning and design of the Citytunnel have taken place in close collaboration with the citizens of Malmö and especially with those living nearby. This consultation has continued while the work is in progress. Project Leader Michael Myhré explains that information meetings are held with the residents in the Triangeln area, as well as with neighbouring schools and churches. ‘So far, these contacts have been characterised by very great understanding about the disturbance which began in the form of traffic restrictions and noise’, says Michael Myhre.
Currently, tunnelling work employs some 500 people, a figure that may eventually rise to around 1,200. When the rail tunnel between Malmö C and the Öresund Bridge is complete in 2011, it is expected that Triangeln will be Sweden’s third largest railway station after Stockholm and Gothenburg in terms of numbers of travellers, estimated at around 40,000 per day.
Increased rail travel will also mean significant environmental gains for the whole Malmö and Öresund region.