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This is a collection of frequently answered questions about the planned MAXIMA wastewater treatment system.

A regional solution for several municipalities

What is MAXIMA?

The MAXIMA wastewater treatment system is VA SYD’s investment in a new regional infrastructure for sustainable wastewater treatment in the member municipalities of Burlöv, Lomma, Lund and Malmö. This will be one of the biggest infrastructure investments in the region in the near future and is essential if the growth region of southwest Skåne is to be able to continue to grow. With a shared solution, VA SYD meets the need for expansion and modernisation of the wastewater treatment system in the municipalities, protects local aquatic environments and allows cities to grow. 

What does MAXIMA include?

MAXIMA currently includes a robust new Sjölunda wastewater treatment plant on the outskirts of Malmö next to the Öresund, outlet pipes into the Öresund, a large new pumping station at the Sjölunda wastewater treatment plant, a wastewater tunnel beneath the centre of Malmö, and a northern wastewater tunnel to connect the municipalities of Burlöv, Lomma and Lund as well as Hjärup in the municipality of Staffanstorp to Sjölunda wastewater treatment plant. Existing wastewater transfer pipes will connect the wastewater from Bara and Klågerup, in the municipality of Svedala, to the wastewater tunnel beneath Malmö. 

What is the estimated cost of MAXIMA?

Building the MAXIMA wastewater treatment system is estimated to cost SEK 17,5 billion by 2035. The cost will be shared fairly and sustainably between the municipalities that benefit from the plant. 

How are the municipalities and treatment plants in southwest Skåne affected?

It is more economical to expand in one place instead of several local treatment plants. Sjölunda wastewater treatment plant is a more suitable location in terms of both impact on the aquatic environment and urban development. 

When we expand the Sjölunda wastewater treatment plant in Malmö, we are building and modernising for the region. This may mean that the community no longer needs several local treatment plants, and the sites can be used for other purposes after decommissioning. It will be more economical for each municipality not to need to expand and modernise their local wastewater treatment plant.

Is it not better to invest in new property-based wastewater technologies?

There is no contradiction between planning to develop our main regional wastewater treatment system and new wastewater technologies. However, it is important to realise that the water supply and wastewater infrastructure we have today, and on which we are completely dependent, has been built up over more than a century. It needs to be managed, renewed and adapted to new requirements.

Converting it to something else, such as property-based solutions, would take a very long time with unpredictable costs, as the technical solutions do not exist on a large scale today. Regardless of how things develop, we need a sustainable, robust water supply and wastewater system that stands the test of time. 

Has a decision been made to build a new regional wastewater treatment system?

Work is now under way to establish an owners' decision to invest with the municipalities concerned. This is necessary to allow VA SYD to continue the planning and implementation of MAXIMA. You can read more about the decision-making process here.

What is the alternative to a major new regional wastewater treatment plant in Malmö?

If invited municipalities reject a regional solution, they will need to expand and modernise their local wastewater treatment plants. This will be necessary to cope with strong population growth and stricter environmental legislation.

Why does VA SYD favour a regional solution over local expansion?

The idea that regional expansion is better than several local expansions is supported by our collective expertise at VA SYD, studies, and reports and external analyses from the Swedish trade association Svenskt Vatten. You find this material under Information material and Reports and studies.  

Svenskt Vatten points out that a large organisation and cooperation are required to meet the re-quirements for costs, staff, expertise and advanced treatment technology. You can read more about this in Svenskt Vatten’s 2023 investment report.

How does MAXIMA affect our environment and community?

What does the expansion mean for the community?

Investment in wastewater collection and treatment is necessary to permit cities to grow. Our current water supply and wastewater system is old and cannot cope with the challenges of climate change, population growth and new environmental legislation. With MAXIMA, we are modernising the wastewater treatment system to meet these needs.  

What will be the environmental impact on the aquatic environment when MAXIMA has been completed?

In the operational phase, the new wastewater treatment system will mainly affect our aquatic environment in two ways.

With new treatment technology at the Sjölunda wastewater treatment plant and new outlet pipes further out into the Öresund, this will be a major improvement. This means that we will reduce the impact compared to today, when the existing outlet pipe discharges near the coast into more stagnant water in Lommabukten. In addition, we will reduce discharges into rivers (Höje å, Lödde å and Sege å) that flow into Lommabukten when local plants can be closed. 

The second environmental impact is caused by overflow discharges, i.e. when the volume of water exceeds the capacity of the wastewater system and we release untreated wastewater into the nearest watercourse for safety reasons. Overflow discharges into Malmö’s canals currently occur around once a week. When we put the new wastewater tunnel beneath the centre of Malmö into operation, we estimate that overflow discharges will occur only once or twice every ten years. The new wastewater treatment plant in Sjölunda is being built so that there is no overflow discharge from the plant itself and the entire system will be able to handle an exceptional rainfall event.

In addition, the wastewater will be transferred by gravity, meaning that the water will flow under its own power to a pumping station at the wastewater treatment plant in Sjölunda. There, the wastewater will be pumped about 30 metres from the bottom of the tunnel to the treatment plant.

How safe is regional coastal expansion, compared to local inland expansion, in terms of climate change and disruption?

By pooling our financial resources and expertise, we can invest in a safe, robust plant. We will incorporate solutions in the new wastewater treatment plant that protect against disruption, and we will invest in back-up systems that will allow the plant to continue receiving wastewater if disruption does occur.

We will also build the new wastewater treatment plant so that it is protected against the expected sea level rise (up to 2100).

What environmental considerations does VA SYD take into account during the planning and con-struction phases?

We study and monitor this on an ongoing basis. Our ambition is to minimise the environmental impact during the construction phase. 

Studies show that the environmental impact during the construction phase is limited and lasts for a limited time. The construction methods we plan to use are well proven (tunnelling and retaining walls), and have a limited environmental impact in terms of noise, vibration and groundwater. To further reduce the environmental impact, VA SYD is planning various protective measures such as noise barriers and treatment of water before it is released into ditches or watercourses.

Prior to the construction of new outlet pipes in the Öresund, we have studied and analysed how we can minimise our impact on sensitive natural areas (Natura 2000 sites and nature reserves). Our impact is expected to be relatively short-term and the recovery time for eelgrass and fish is considered to be manageable.

How does VA SYD ensure economic viability?

The actual costs involved are emerging over time as we learn more about factors such as the construction conditions. We ensure that it is economically viable by continuously analysing benefits, impacts and costs. We keep the costs down by sharing the investments between several parties.

These are major investments that are necessary for our community to grow and function without any negative impact on our health and environment. They are also necessary investments to enable us to meet stricter environmental requirements.

Who will pay?

VA SYD is preparing a proposal on how the municipalities concerned can share the cost, which will form the basis of our owners' decision to invest.

Regardless of the implementation of our infrastructure investment, charges for water supply and wastewater (your water bill) will need to be gradually increased, and possibly doubled within 20 years, according to the trade association Svenskt Vatten. Water and wastewater management currently suffers from maintenance neglect and a lack of investment in Skåne and throughout Sweden.

The principle of all aspects of the management of wastewater, drinking water and waste is that customers pay by means of a charge determined by the tariff. The cost principle applies, so it is not a profit-making activity.

A robust new Sjölunda wastewater treatment plant

When can a new treatment plant be completed at Sjölunda?

We plan to have a new regional plant up and running from between 2035-2037. A growing population and the aquatic environment in the region require this. The timetable is dependent on ongoing technical studies, implementation agreements and new environmental permits not being delayed.

How far into the future is VA SYD planning for the new Sjölunda wastewater treatment plant?

We plan for the entire plant to be able to manage a projected flow up to 2045 from the start. This is as far as we can obtain relatively accurate projections of population growth in the region. We plan to build the new wastewater treatment plant in such a way that we will able to upgrade and change it in line with new needs and new technologies.

Sjölunda wastewater treatment plant currently receives wastewater from 300,000 people in the region. By 2045, Sjölunda is expected to be able to treat wastewater from almost 700,000 people. 

How will you manage to build a new wastewater treatment plant that stays modern over time?

It takes up to eight years to build a new regional wastewater treatment system. During that time, growth, technological development and digitisation continue. The planning of the new Sjölunda regional wastewater treatment plant takes this into account. From the outset, we are planning for the plant to meet stricter new environmental requirements and the needs of the municipalities of Burlöv, Lomma, Lund and Malmö up to 2045. The design and layout will be adapted so that it can be continuously upgraded to meet new requirements and incorporate new technologies, even after 2045. 

Where will the new Sjölunda wastewater treatment plant be built and what role does the geographical location play?

VA SYD has studied the location of the new wastewater treatment plant and concluded that the best location is where the Sjölunda wastewater treatment plant is located today, in Norra hamnen in Malmö. This is also supported by dialogue with the City of Malmö when looking at alternative sites. The City of Malmö is not planning any housing in the area in question. Several industrial facilities are close enough to develop eco-friendly partnerships with Sjölunda wastewater treatment plant. The Öresund is also such a large recipient of wastewater that the environment will not be harmed by investing in better treatment technology and expanding the plant. You can read more about this in the Location Study on the page Studies and reports.

What treatment process is envisaged for the new wastewater treatment plant?

Our feasibility study, our project objectives and specific conditions have led us to choose to proceed with MBR (membrane bioreactor). Our feasibility study, our project objectives and specific conditions have led us to choose to proceed with MBR (membrane bioreactor). 

What is MBR?

MBR stands for membrane bioreactor. It is a biological process for treating wastewater in which the treated water is separated from the sludge by membranes. These membranes have extremely small pores that allow only the treated water to pass through but not the sludge. An MBR produces extremely clean water thanks to the membranes and needs a limited physical area at the wastewater treatment plant, making it a space-efficient process.

How does MBR differ from the current treatment process at Sjölunda?

Wastewater is treated biologically in the same way with microorganisms in both an activated sludge process, as used today, and an MBR process. The difference between the processes is the technology used at the end to separate the sludge (pollutants) from the treated water. In the current process, the sludge is separated by gravity, while an MBR uses membranes with extremely small pores that stop the sludge and allow the treated water to pass through. MBR stands for membrane bioreactor. An MBR requires less space than the current activated sludge process, but requires more energy. 

How did VA SYD arrive at MBR?

In the feasibility study for an expanded, converted Sjölunda wastewater treatment plant, we initially considered all possible technologies for a new wastewater treatment plant. There are quite similar processes to choose from, so we needed to perform an in-depth evaluation. The guiding factor was how best to achieve our project objectives for the new wastewater treatment plant. We have project objectives linked to operational reliability, flexibility, climate and energy efficiency, resource efficiency and health and safety. In addition to the project objectives, we need to take into account the entire construction process and the fact that we will be building a new plant while having an existing plant running on the same site. Overall, MBR is the most favourable option.

Wastewater tunnels

What is the difference between a tunnel and a pipe?

A tunnel is built with a large tunnel boring machine that is propelled forwards at a depth of 17-30 metres. The tunnelling is hardly noticeable above ground. The impact on the environment is mainly at the tunnel shafts where we lower the machine and remove soil. The wastewater tunnel will have a diameter of approximately 5 metres. The dimensions of the tunnel will allow us to cope with climate change and growing cities for many decades. The incline of the tunnel will allow the water to travel by gravity.

A pipe is buried at a shallow depth of 3-5 metres and requires a larger working area along the entire route. A pipe also means that we need to build pumping stations along the route to move the water forwards. 

When will the wastewater tunnels be completed?

The wastewater tunnels are planned to be completed at the same time as the other components of the MAXIMA wastewater treatment system. The entire MAXIMA system will be operational between 2035 and 2037 according to the current timetable. 

How is maintenance managed in the wastewater tunnels?

The MAXIMA wastewater tunnels are designed to be self-cleaning, and not need overhaul and repairs that mean you need to go down into the tunnel. The wastewater flows well with the help of self-fall, and if something still gets stuck along the way, the next big rain will solve the problem. The construction of the whole wastewater treatment system also means that flooding will not occur in the tunnels. However, there will be descent capabilities, for handling extreme situations.

How are gases such as hydrogen sulphide handled in the tunnels?

Through natural processes in wastewater, substances are broken down, and new ones are formed. Some substances are in gaseous form and can be harmful to health, for example hydrogen sulphide. Therefore, the wastewater tunnels have ventilation systems ensuring that gases like that are vented out in a safe manner.

The southern wastewater tunnel

Why does Malmö need a wastewater tunnel?

Malmö’s current system that pumps wastewater from the centre of Malmö to the Sjölunda wastewater treatment plant is old, with parts dating back to the early 20th century. Malmö needs a new system to cope with rapid population growth and new environmental requirements. A tunnel will allow Malmö to grow and develop sustainably as a city.

In November 2019, Malmö City Council made a policy decision to build the tunnel.

How will the City of Malmö be affected by a wastewater tunnel?

A tunnel will have several positive community effects:

  • A robust wastewater system that will last for 100 years and cope with population growth.
  • Much less traffic disruption during construction and future maintenance.
  • Less pressure on our aquatic environments.
  • Better conditions for urban development as the tunnel will be built at a significant depth.
  • Reduced risk of basement flooding near Malmö’s canals.
  • Lower costs for a new Sjölunda wastewater treatment plant. The tunnel will have a storage function that will relieve pressure on the treatment plant.

How will a tunnel affect Malmö’s aquatic environment?

The pollutant load on Malmö’s canals will be significantly reduced by a wastewater tunnel. The tunnel will reduce the discharge of untreated wastewater (overflow discharge), which occurs during heavy rainfall, by 90 per cent. A tunnel will also reduce discharges into Industrihamnen and Sege å.

What is the route of the wastewater tunnel?

The preliminary route of the main tunnel is from Turbinen (at the Technical Museum) in Malmö via Norra hamnen to Sjölunda wastewater treatment plant. The two connecting microtunnels are planned to run from Värnhemstorget to Skruvgatan and from Spillepengen pumping station to Sjölunda pumping station.  

Could the wastewater tunnel beneath the centre of Malmö prevent future expansion of the port areas?

No, a wastewater tunnel benefits urban development. It will be built deep below other pipes and will allow a larger volume of wastewater to be received from more homes and businesses.

Can the wastewater tunnel eliminate basement flooding in Malmö?

The wastewater tunnel will minimise the risk of basement flooding in these areas: Ribersborg, Kronprinsen, Fågelbacken, Gamla Staden, Rörsjöstaden, Slussen, Östervärn and Segevång. To reduce the negative effects of heavy rain and rising water levels throughout Malmö, VA SYD and the City of Malmö are working on a joint action plan - Joint action to make room for water.

The northern wastewater tunnel

Why a tunnel connection from the north?

Studies show that a tunnel connection from the north for the transfer of wastewater best fulfills the benefits to be delivered:

• Securing growth and meeting a growing population 
• Protecting our aquatic environments where we want to live and operate 
• Recycling energy and nutrients for society 
• Strengthening VA SYD and its members to cope with necessary future investments 
• Creating a robust and reliable wastewater treatment system.

Tunnels for wastewater are becoming increasingly common in densely populated communities and regions with strong population growth. In the Nordic countries, existing and planned sewage tun-nels exist in cities such as Copenhagen, Stockholm, Gothenburg, Oslo, and Helsinki. 

Which towns will be connected?

Currently, the tunnel is planned to pass under the Hjärup urban area, where the existing pumping station will be decommissioned. The urban areas of Arlöv, Lomma, and Åkarp are connected via a previous system, ABMA (Aktiebolaget Malmöregionens avlopp). A new pipeline system connects the urban area of Bjärred. All will become part of our regional wastewater treatment system MAXIMA. 

How long will the tunnel be?

The wastewater tunnel will be a sealed concrete tunnel with an internal diameter of 3,0 meters and will be approximately 10 kilometers. The tunnel will be located at a depth of 25–30 meters.

How will the land and environment be affected?

The tunnel connection is expected to require a land claim of approximately 3,000 square meters during operation and approximately 40,000 square meters during construction. Access roads and material storage areas will be added during both operational and construction phases. Temporary groundwater lowering will be required during excavation.

There will be exhaust- and particle emissions, and construction activities will also impact noise and vibrations. However, planned protective measures will ensure that noise limits are met, and analyses of expected vibrations and settlement from tunneling indicate negligible impact.

The alternative to a tunnel that has been explored is a conventional pressurised pipes system. However, a tunnel is both more cost-effective and has less impact on our surrounding environment. Read more about the different alternatives here (the PM is in Swedish)

Communication with property owners

How and when will I be contacted if the wastewater tunnel/pipes will run under my prop-erty, on my land?

Before we start building the wastewater tunnels and new pipes to connect the municipalities, we will sign land grant agreements with the property owners who own developed and undeveloped properties along the route in question. This agreement regulates, among other things, where the tunnels and pipes will be located and what landowners will receive. 

VA SYD will contact each individual land/property owner by letter or in person to present the land grant agreement. We will also provide information about the principles applicable when we value and compensate property owners for encroachment and the impact of construction of the tunnels/pipes. We always endeavour to reach an agreement with property owners. By signing a land grant agreement, property owners authorise the construction of the tunnel/pipe along a specific route on their property. The land grant agreement gives VA SYD the right to build and manage the new infrastructure. The agreement governs the conditions that will apply when we, as the pipe owner, make use of the land, and the compensation principles that will apply to encroachment and settlement of any damage. Based on the land grant agreements, VA SYD will commission Lantmäteriet (the Swedish Land Survey) to decide on utility easements. A utility easement means that the terms of the agreements are converted into a legal right that is clearly recorded in the land register and the register map belonging to the land register. 

What happens if we do not agree and do not sign a land grant agreement?

If you choose not to enter into an agreement with us, the matter will be referred to Lantmäteriet to assess whether it is possible under current legislation to make a decision on a utility easement. You can also choose to sign the agreement without accepting the compensation we offer. In that case, we agree on all other terms of the agreement and it is only the matter of compensation that is submitted to Lantmäteriet.

What kind of compensation will I receive if my property is affected by the wastewater tunnel?

VA SYD offers affected property owners a one-off payment of compensation. This is based on an assessment of the value of the encroachment on the property. The principles of the compensation are regulated in the Expropriation Act, which states that the property owner must receive compensation based on an assessed reduction in market value plus a 25 per cent surcharge. We also compensate any damage to buildings and other property that may occur during the construction of the tunnel.

How will my property be affected by noise and vibration during construction?

A technical study will be carried out to establish which properties may be affected by noise and vibration during the construction of the wastewater tunnels. Impacts may be caused by the construction of the tunnel itself and also, for example, by heavy transport. The properties at risk of impact will be inspected and documented prior to the start of construction.

The construction methods we plan to use are well proven and have a limited impact in terms of noise, vibration and groundwater. The tunnels are being built at a depth of 17-30 metres and the tunnel boring machine advances rapidly. This means that a property may feel vibrations from the boring machine for a maximum of one week. Shafts used in part for transporting excavated material will be active for around 18 months.

What is the procedure for property inspections?

All buildings and facilities that may be affected by the wastewater tunnel construction project are inspected by an independent inspection company both before and after the work. VA SYD will inspect all buildings deemed to be at risk of damage. We will contact you well before we start our work so that you are prepared and can think about any questions you may have.

How will I be compensated if my property is damaged during the construction phase?

If you discover damage to your property after we have completed construction in your area, you can apply for compensation. An independent inspection company then carries out a damage study to assess the causal link between the damage and the work carried out. You will be fully compensated for any damage deemed to have been caused by the tunnelling.

Permit process

Why is VA SYD applying for an environmental permit?

To build and operate the MAXIMA wastewater treatment system, VA SYD must obtain an environmental permit under Chapters 9 and 11 of the Environmental Code. This legislation regulates activities with an impact on health and the environment. The permit application is submitted to the Land and Environment Court at Växjö District Court, which handles cases concerning environmental and water issues for our region. They assess whether the construction and operation of the new wastewater treatment system is compatible with environmental protection laws.

How do the proceedings at the Land and Environment Court take place?

The proceedings at the Land and Environment Court may take around two years. When the court receives the application, it first assesses whether the application needs any additional information. Once the application is complete, the court publishes a notice (advertisement) in the local press. This begins a consultation period in which parties concerned, the general public, municipalities, the county administrative board and other public authorities are given access to the plans for MAXIMA and have the opportunity to comment on the case. VA SYD must respond to the comments received. Once the consultation period is over, the court holds a main hearing that is open to everyone. The hearing is likely to be held in Malmö.

The application for a permit results in a judgment stating whether the activity may be carried out or not and the conditions that apply to the permit. The judgment may be appealed against to the Land and Environment Court of Appeal by you or others who are affected. The deadline for appeals is stated in the judgment.

Can I comment while the application is being considered?

Yes, you can. The court will publish a notice (advertisement) in the local newspaper when the application is complete. This starts a consultation period during which you can comment on the planned wastewater treatment system. You are also welcome to attend the main hearing, which is likely to be held in Malmö.

How can I access the application documents?

The application documents are available on our website. You can find the application documents here.

What does consultation mean for the permit process?

The consultation process is an important part of the permit application. Consultation gives parties concerned the opportunity to influence the process by submitting their views.

VA SYD and the county administrative board have jointly evaluated that the activity is considered to have a significant environmental impact, which means that a more detailed environmental impact assessment (EIA) is required and the consultation is extended to include more stakeholders. After the consultations, a consultation report is compiled that contains responses to the comments and views received and an account of the consultation meetings held with the stakeholders concerned. VA SYD has carried out several consultations and additional consultations within the framework of MAXIMA. Read more about the consultations here.