The Kalundborg Symbiosis, a closed-cycle industrial collaboration
The Kalundborg Utility is situated on the north-western coast of Zealand in the City and Municipality of Kalundborg. Due to a change in legislation, the company separated from the Kalundborg Municipality in 2009 to continue as a private limited company with all shares owned by the municipality. The company provides products and services including drinking water, processed water, wastewater treatment and district heating.
The utility shares a geography with a number of Danish and international industrial manufacturing companies. Some of these companies, together with the utility and the municipality, are partners in the Kalundborg Symbiosis, a closed-cycle industrial collaboration. Kalundborg Symbiosis has existed for more than forty years and is a system where one partner’s residuals become another partner’s resource.
The main challenge that the Kalundborg Utility faces is the ability to cope with the demands from the dense industry from the city without negatively impacting the water basin or water sources with the effluent.
The current 4-year strategy aspires to inspire and create social and environmental value within the Kalundborg Utility and City.
‘Five Landscapes’: which is still in beginning stages, is a project to use existing green urban areas to mitigate and manage stormwater and rainwater by delay or percolation.
There is a focus on seeing wastewater as “resource water” which is strongly supported by the DEA (Danish Energy Agency), due a testing and demonstration programme.
The main challenge that the Kalundborg Utility faces is the ability to cope with the demands from the dense industry from the city without negatively impacting the water basin or water sources with the effluent. As the Kalundborg Utility set out as a municipal company, the main purpose of the utility was to ensure the security of supply that lives up to national regulations.
Since the Kalundborg Utility’s separation from the municipality in 2009, it has developed a solid strategy to emphasize its sustainability goals and integrate a secured water supply into its business model.
The current 4-year strategy aspires to inspire and create social and environmental value within the Kalundborg Utility and City. The goal of this strategy is to re-define sustainability while fulfilling traditional virtues including: low prices, high quality, and security of water supply. The Kalundborg Utility aims to create a business that will meet future demands without harming its ecosystems. This is demonstrated by assuming the role as a water operator to ensure sustainable water-use through a critical assessment of the entire water cycle of the company; where actions are based on high quality knowledge of the hydrological environment.
To cope with the increasing amount of cloudbursts, the Kalundborg Utility and the Kalundborg Municipality have engaged in a project called ‘Five Landscapes’. The vision of the project, which is still in its beginning stages, is to use existing green urban areas to mitigate and manage stormwater and rainwater by delay or percolation. At this important planning stage, the citizens are invited to give their opinion in the project as they will be the end users of the five landscapes. The purpose of this initiative is to increase groundwater percolation and reduce need for excessive stormwater piping infrastructure.
The Kalundborg Municipality regulates the utility according to Danish legislation. Additionally, the Kalundborg Utility is subject to national benchmarking by the Danish Water and Wastewater Association. The collaboration between the utility and the City is well-adjusted and based on a shared vision and collaboration. In the utility’s board are six politicians from the city government who manage the alignment of the municipality and the utility in terms of strategy and direction towards a shared vision. To support this line of thought, the utility and the municipality have monthly meetings.
As all other big-scale utilities in Denmark, the Kalundborg Utility is a monopoly, which means that the Water Division under the Danish Competition and Consumer Authorities monitors and regulates the utility. The Water Division creates fixed price ceilings and efficiency demands for all Danish water companies to ensure fair and low water prices. For the same reasons, the Water Division benchmarks all water utilities in Denmark on a yearly basis. Thus, Kalundborg Forsyning relies on a self-sustained financial principle, in which surplus is not allowed. In other words, the accounts have to break even.
In Kalundborg, there is a high degree of reuse of water, i.e. water used for cooling will afterwards be used as feed water to district heating. There is a focus on seeing wastewater as “resource water” which is strongly supported by the DEA (Danish Energy Agency), due a testing and demonstration programme.
As a special solution in Kalundborg, industrial wastewater is discharged to the treatment plant in a separate pipe system and is not mixed with sanitary wastewater from the city before it reaches the treatment plant. This means that we on the treatment plant can decide if the water can be reused as industrial process water. However, if the industrial water is mixed with sanitary waste water the legislation for reuse is much more complicated.
As such, Kalundborg Utility is also obligated to charge a special fee for companies leading highly polluted wastewater to the waste water treatment plant. This fee exists to make sure that the polluting companies pay the costs of coping with their negative externalities.
Kalundborg Symbiosis is a circular economy collaboration project between the City of Kalundborg and a number of private companies in the area. These companies benefit from the residuals from their collaboration partners. One partner’s waste becomes another partner’s resource. This model was developed more than 40 years ago and was founded with economic interests in mind, and it was not until later that the environmental benefits of the symbiosis were recognized. In Kalundborg the waste water from the industry is used for biogas production, heat pumps for district heating and there is a discussion to look into phosphorus and nitrogen removal and production.
The Kalundborg Utility is involved in three main types of water streams in the Kalundborg symbiosis. First, the utility supplies treated and untreated surface water in two qualities from Lake Tissø to Novo Nordisk and Novozymes (pharmaceutical and enzymes factories). By using surface water, the scarce groundwater resources are preserved. Second, the utility receives industrial and household wastewater, which is cleansed at one of Europe’s most advanced wastewater treatment plants in Kalundborg. Here, complex wastewater from the industry can be treated in one of the many specialized processes including an ozone plant and moving bed biofilm reactor (MBBR) technology. The ozone plant was built in 2002 and it was co-financed by Novozymes and Novo Nordisk. At the time, it was necessary to make use of this best available technology to comply with legal requirements to the discharge quality. The industry has since then developed their pre-treatment of the wastewater, and today Kalundborg Utility only runs the ozone plant during rare peaks.
The industries’ manufacturing of insulin and enzymes has shown great potential for biogas production. Novozymes, Novo Nordisk, DONG Energy, and Bigadan have agreed to produce biogas from 2018 using residual products from fermentation processes. Bigadan will sell the sludge from the biogas production to agricultural purposes, which are not suited for sanitary sludge from Kalundborg Utility. Currently, Kalundborg Utility is exploring the possibility to put up a digestion tank and sell the gas to Bigadan’s upgrading facility.
Until now, the only by-product from Kalundborg Utiliy’s wastewater treatment plant has been sand and sludge. The utility uses the residual sand to refill sewer renovations after a sanitation process. While the sand is re-used internally in the company, the sludge, which lives up to national regulations, is drained and spread on farmland.
As of 2017, the utility is constructing a large-scale heat-pump, which will be able to transfer heat from the unusually hot industrial wastewater to the district heating network. By doing so, Kalundborg Utility will supply district heating with a minimum of negative environmental externalities and can lower the temperature of the effluent. This innovation reduces carbon emissions by 16.000 tons yearly and covers 30% of the annual district heating supply.
The area of Kalundborg is unique in many ways. The medieval city is relatively small with no more than 50,000 inhabitants in the municipality. But Kalundborg has attracted an unproportioned number of manufacturing industrial companies due to the big harbour and industry-friendly municipal policies. Therefore, the main concern regarding water in Kalundborg has to do with ensuring a growing water supply for the industrial customers without harming the natural water environment or detracting from inhabitants’ water supply.
Historically, Denmark has had abundant groundwater resources, but to preserve these drinking water resources, Kalundborg Utility is building version two of its surface waterworks, which will supply industrial process water in two qualities from Lake Tissø – untreated water or treated water in drinking water quality.
Another way of meeting the challenges of tomorrow, is the campus-like environment, which the utility is developing by engaging in a local Bachelors education in engineering, which specializes in biotechnology. The utility is working to attract masters’ and PhD-students together with interns from a wide range of educational backgrounds.