Sustainable soil management in Central Region Session ThS 7a

Future

By: Arense Nordentoft Email: [email protected] Phone: +45 51 36 88 79

Susanne Arentoft Email: [email protected] Phone: + 45 245 66 48 23

Keywords: Surplus soil, sustainable soil management, Strategic planning, Denmark

Regional Development

SUSTAINABLE SOIL MANAGEMENT IN CENTRAL DEMNARK REGION

Central Denmark Region is one of five administrative units in Denmark with the responsibility, among others, to inspect and clean contaminated sites.

Central Denmark Region covers a geographical area of 13,142 km2, equivalent to almost 30% of the total geographical area in Denmark, and the number of inhabitants is equivalent to approximately 23% of the Danish population. Central Denmark Region is divided into 19 municipalities. The eastern part of the region has a number of municipalities with a considerable building activity. In a number of the western municipalities building activities are lower.

Denmark and

the five regions North Denm ark Region 0.6 million

Central Denm ark Region 1.3 million

Capital Region of Denmark 1.8 million

Region of Southern Denm ark 1.2 million Region Zealand 0.8 million

2 ▪ www.english.rm .dk

In Denmark, excavated soil from possibly contaminated, contaminated or classified areas (typically located in cities) must be reported to the municipality. In 2017, the Danish Environmental Protection Agency made an account of the annually reported amounts of soil in 72 of Denmark’s 98 municipalities in the period between 2011 and 2015.

Total amounts of soil (tons)

The figure shows that the annual amount of reported excavated soil is between five and six million tons. This is in addition to surplus soil from areas where there is no demand for reporting to the municipality; this amount is considered to be of at least the same size.

Of the reported amounts of soil

 at least 1 – 2,3 million tons is clean soil  at least 0,5 – 1,0 million tons is slightly contaminated soil  at least 0,3 million tons is contaminated soil  at least 0,6 million tons of soil is of unknown degree of contamination.

In Central Denmark Region we estimate that the building industry on average generates 6 million tons of surplus soil annually. This is in addition to surplus soil generated in connection with sewerage work, road projects and similar. Thus, the amount of surplus soil produced in Central Denmark Region is significantly larger.

Typically, surplus soil is replaced by new sand and gravel materials from raw material pits. We have many raw materials in Denmark; however, in the long term and in some parts of the country there will be a shortage – unless we do something.

Surplus soil is transported to a landfill (if contaminated), reused or used as fill up in raw material pits (clean or slightly contaminated soil). Surplus soil is often transported to landfills over long distances instead of being reused locally.

Overall, we see the following problems in relation to what we do now:

 Other landfills for surplus soil must be found  It costs a lot of money in transport and landfill taxes

 It also has environmental costs related to CO2, particle and noise pollution  It has a negative effect on congestion, accidents and road maintenance  Materials removed from a project are often replaced by valuable raw materials  Social opportunities in creative landscapes are wasted by always removing surplus soil.

Project Sustainable soil management Central Denmark Region has instigated a two-year project which aims for more sustainable solutions, i.e. more recycling and up cycling of soil. The project is driven by a steering group of representatives from Central Denmark Region and from four different municipalities in the Region.

The project focuses on two main issues – networking and strategic planning:

Networking To achieve success, a stronger network is essential. A basic element in the project will be two annual workshops, where a wide selection of stakeholders is invited to exchange knowledge, change old habits and find new common solutions. Examples of agenda items could be local planning, technical solutions, soil stock exchange, multiple soil use purposes etc.

Strategic planning Overall strategic planning initiated by local authorities can provide new opportunities for local reuse. A good excavated soil strategy should involve different departments such as district planners, environmental officers etc. There are a few Danish examples of such strategies. The project began in January 2018 with a kick-off workshop inviting all 19 municipalities in Central Denmark Region. The aim of this first workshop was to identify common challenges and needs as well as relevant stakeholders.

Challenges and needs were surprisingly few, and through a prioritisation process the following main objectives were chosen to be transformed into action and deliverables in the project:

 Biannual workshops to strengthen networking and knowledge exchange between all important stakeholders  A GIS-based forecast tool to estimate the amount of soil excavated in each municipality over a period of 10-12 years based on planning data from residential, industrial, infrastructural areas etc. The purpose is to illuminate the need for and strengthening of a local soil strategy  A report template to motivate and guide the municipal planners through the process of making a local strategy for excavated soil; this includes making a vision, stakeholder analysis etc.  Catalogue of 20 existing soil reuse projects with good variation in size, type and stakeholders involved - also including business cases. This should work as inspiration to alternative use of soil in future projects.

The joint tool box to promote more strategic planning in Central Denmark Region comprising a forecasting tool, a joint template for local strategy planning and an inspiration catalogue was ready by the end of 2018.

The need for new solutions is obvious - clearly identified through the interest in the subject and the number of attendants at the workshops and meetings. Thus, workshop 3 in October 2018 successfully gathered 70 people including municipality representatives, consultants, architects, contractors, soil receivers and utility companies. In addition to introducing the attendants to the strategy template, other important subjects were eagerly debated such as soil stock exchange, lime stabilisation and local planning. Networking and exchange of knowledge will be further developed by biannual workshops or meetings. Obviously, different stakeholders have different drivers, but sustainability with a triple bottom line: People, Planet, and Profit makes an inspiring and dynamic starting point leading towards the common goal. So far, the project has clearly confirmed that breakdown of boundaries between stakeholders and different disciplines is the key to success. We can only encourage promoting further networking on the subject. We are, of course, eager to hear from anybody with new angles, good ideas, interest in or knowledge of the subject.

The new tools to help local authorities make strategic planning and inspire all stakeholders to reuse excavated soil will be implemented and tested during 2019/2020. Some of the cases from the inspiration catalogue are attached.

ANNEX, EXAMPLES

Infrastructure

Light Rail Bridge Including Reused Contaminated Soil in Project type: Reuse of slag containing and contaminated soil infrastructure, light rail bridge. Place: Aarhus Quantity: 4,300 m3 CO2 saved: 5,000 kg KM saved: 6.300

In connection with the setting up of the light rail train in Aarhus, several projects have been re-using surplus materials.

In order to lead the light rail tracks forward to the traffic and service center at P. Hiort Lorenzens Vej it has been necessary to build a bridge. In connection with the establishment of the bridge, it has been possible to reuse soil that has been dug up in connection with the establishment of tracks for the light rail. In this project, the surplus soil has been dug up only a few meters from the construction site.

The bridge over the Bane Denmark's tracks at the driveway to Aarhus H, is shaped like a big trough made of concrete. At the bottom of this trough, contaminated soil has been reused, on which new tracks are placed on new chippings. In connection with the project, a total of 4,300 m3 of contaminated soil and slag have been utilized.

The project with the reuse of 4,300 m3 of contaminated soil and slag, has induced a reduction in the supply of pure raw materials, cost reductions for disposal of soil, reduction of heavy traffic in Aarhus City, and finally a reduction in CO2 output.

Infrastructure

Handling of Surplus Soil at the Light Rail in Aarhus Project type: Recycling of soil for bridges and dykes, infrastructure, rail bridges and dams. Place: Aarhus Quantity: 135,000 m3 CO2 saved: 194,400 KM saved: 243,000

In connection with the establishment of the approx. 3.5 km long distance between and Lisbjerg, the focus has been on keeping a neutral soil balance in the project through recycling of surplus soil.

The surplus soil has been reused for recycling in connection with works for bridges and dams.

As the dam works are situated inside and outside areas for drinking water purposes respectively, there has been requirements for which grounds that could be reused. In the dam works situated in the area for drinking water purposes and extraction catchment area for Kastedværket, 65,000 m3 clean soil and lightweight quarry tiles (LECA) have been documented and reused.

In the dam works situated outside the area with drinking water resources, 70,000 m3 slightly contaminated soil has been recycled.

The soils for the bridge and dam works are predominantly from the light trail's own construction works. However, it has been necessary with soil supplies from external projects.

Climate Proofing

Climate Proofing at Lillelund Engpark, Herning Project type: Climate proofing, recreational area, rainwater basins, handling of soils, landscape plans Place: Herning Quantity: 170,000 m3

The project has proofed that it is possible through timely and close collaboration and planning to solve one issue with the help from another issue.

The project has been implemented in order to reduce the extent of flooding at Herningsholm Å (river) that surrounds Herning city. At larger and/or longer lasting rain events the project reduces the water level in the river by approx. 30 cm which is just the difference between success and failure. The project is combined with separate sewerage and a row of recreational elements.

The project has also been implemented in order to make use of a 25 ha large unutilized local area for recreational purposes: The area's accessibility and nature content have been increased, an schools and kindergartens in the area have gotten the opportunity to teach practically in the open. Walking-impaired and handicapped people have gotten access to the area and various facilities have been designed with regard to their needs, whereas joggers have gotten better and longer trails. The new play hills can also be used for mountain biking, kite-flying, toboggan run etc. and the lakes may be used for training, sailing and recreational fishing.

Surplus materials, in the shape of approx. 170,000 m2 soil has been recycled for climate proofing of an approx. 160,000 m2 large industrial and commercial building and also for the establishment of a motorway. Everything is within a radius of 10 km. The project renders a large contribution towards flooding at Herning city. Concurrently, a new large local industrial and business area has been climate proofed against rising ground water levels.