One of Citytunneln’s objectives is for the finished connection to contribute to an environmentally harmonised transport system and a long-term sustainable society. This will be achieved primarily by giving a greater number of people the opportunity to use public transport instead of using the car.
The surroundings and the environment will of course be affected during the construction period in a number of ways. The Citytunnel project has been sanctioned according to the Environmental Code, legislation on the building of railways and planning and building l legislation. A new Environmental Code was passed in Sweden in 1999 which, in many respects, is much stricter environmental legislation than previously.
Voluntary testing
The consequences of the construction have been tested in the Environmental Court. This has been done partly through obligatory testing of lowering the ground water and building in water and through voluntary testing of environmentally hazardous activities and health protection. Citytunneln is the first major infrastructure project that has been fully tested according to the Environmental Code which makes it unique in an environmental context. Citytunneln’s application to the Environmental Court was submitted on 1 March 2002.
The main negotiation concerning that part of Citytunneln with connecting tracks at Hyllie-Vintrie was held during 2003 and 2004. The judgement on this was delivered in December 2004. The judgement covering around 220 pages determines in detail the environmental c conditions for the project both during the construction stage and the operating stage. Negotiations on the last part for the connecting tracks in Lockarp were held in January 2005 and judgement was delivered in November the same year.
Detailed condition for the work
Environmental testing has meant that the Environmental Court has set detailed conditions for how much noise that those who live near to the workplaces shall be subjected to during the construction period. The Court has also decided in detail the maximum amount of ground water that may be pumped away from the construction workplaces.
The decisions by the Environmental Court have, in turn, formed the basis for how agreements with contractors shall be formulated. This has resulted in consequences for the choice of working methods as well as which materials and chemical products may be used.
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A well for lowering of the ground water. |
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Water is pumped up from the ground via extraction wells near the work area and pumped back via infiltration wells some distance away. |
Impact on ground water
The work on Citytunneln means that the water level must be temporarily lowered along parts of the stretch and primarily at Malmö C, Triangeln station and at Holma. Extensive prior examinations, test drilling and test pumping have been conducted to assess the limestone rock’s properties and ground water flows. This has been done according to obligatory testing as stated in Chapter 11 of the Environmental Code.
Lowering the water level has been limited to practical influence areas where buildings, watercourses, surface water and plant life could be affected.
Water pumped back
Water is pumped back to the ground water magazine to limit the extent of the influence areas as much as possible. Water is pumped up from the ground via extraction wells near the work area and pumped back via infiltration wells some distance away. This maintains the water levels in the area around the workplaces. The water levels are monitored via a number of measurement points.
In central Malmö there are buildings on foundations that cannot tolerate a lowering of the water levels. The water levels are also monitored continuously for this reason. South of the tunnel exit there is permanent lowering at certain parts of the stretch. The consequences are limited as much as possible through water being reinfiltrated.
The trees in central Malmö are not affected since their roots do not reach down to the tunnel. It is however necessary to remove a number of trees at the sites where the open shafts are excavated.
No affect on the water level
Since the tunnels are covered with a lining as the tunnel boring machines advance below ground, the boring operation will not require the water level to be lowered. Neither will the water level be affected in the future.
Noise and air pollution
Noise and vibration will be the most significant inconveniences during the construction period. Structure-borne sound that is propagated through the rock up into buildings above ground may occur. Air pollution will arise primarily from the machines that transport material and excavation material.
The Environmental Court has determined levels for both noise and air pollution. The greatest noise nuisance during the construction period arises from excavation of the construction pits, the construction of support walls and transport. The majority of people live, work and move around the workplaces at Malmö C and Triangeln.
Methods with positive effects
Construction noise and vibrations are limited primarily by the choice of working method. Where support walls are constructed in the excavated areas, noise and vibrations are considerably reduced by the choice of one building method in preference to another. During the construction phase, housing, schools and other activities can be subjected to vibration levels that may be noticeable.
A number of machines are electrically driven to reduce air pollution levels. Other machines are equipped with special diesel engines and cleaning equipment. The use of catalysts reduces carbon dioxide emissions by no less that 75 per cent. Several of these diesels are Euro III- classed which means that they produce significantly lower emissions of nitrous oxide per unit of energy consumed than standard engines.
Structure-borne sound
When the tunnel boring machines advance below Malmö, the buildings above can be subjected to noticeable structure-borne sound. The low-frequency sound that is generated when boring machines are in operation can cause disruptions over short periods. Measures will be implemented to reduce the structure-borne sound that is generated as a consequence of
rail traffic in the tunnels during the operating stage.
Protection measures
Screens and embankments are used to reduce the noise. With the protection measures in place, the noise from rail traffic during the operating stage will be within the Swedish National Rail Administration’s and the National Swedish Environment Protection Board’s guidelines for good environmental quality.
Cleaning waste water
The wastewater from the building sites can contain earth and limestone particles. There can also be low levels of oil from engines, form oil and concrete residues, tensides and polymers from tunnel boring as well as injection material residues. Water management comprises a number of measures.
The innermost part of Inre hamnen at Skeppsbron has been converted into a treatment plant where wastewater can be cleaned to remove concrete dust and other pollutants before being released into Öresund. The separation is an important measure for compliance with the conditions for release into the sea.
As a result of different cleaning measures and flow regulation, the contents are so small that the wastewater can be led out into Öresund without having any negative impact on the environment. The Citytunnel project’s schedule of activities are compiled in accordance with the requirements of ISO 9001 (quality management system) and ISO 14001 (environmental management system).
Clean excavation mass from the building of Malmö C and Triangeln station plus boring mass are transported to Norra hamnen as infill. |
To avoid trucks contaminating the streets, each workplace is equipped with automatic washing sites which flush the trucks’ wheels and undersides clean. |
Waste and excavation mass
Solid waste is generated in the form of “normal” building waste, demolition waste and household waste from staff facilities. Only a small proportion of the construction and demolition waste requires special treatment. Oil waste and chemical residues are treated as hazardous waste. Household waste is treated as such.
Clean excavation mass from the building of Malmö C and Triangeln station plus boring mass are transported to Norra hamnen as infill. The excavation mass therefore contributes to the continued development of the harbour. To avoid trucks contaminating the streets, each workplace is equipped with automatic washing sites which flush the trucks’ wheels and undersides clean.
Clean excavation mass from the construction of Hyllie station, the connecting tracks south of Annetorpsvägen and in the Lockarp area that is not used as noise embankments is used primarily for terrain modelling. The rest is transported to Norra hamnen.
Checking chemical products
All chemical products that are used are checked carefully. Checking is done by referring to safety data sheets and via an analysis of the products’ physical and chemical properties. An environmental risk analysis is also conducted for products that can come in contact with the ground and water. This is based on handling, working methods, quantities used and methods of use.