Introduction
The remediation work at the Volgermeerpolder chemical dump site will officially end on Tuesday, 19 April 2011. A ceremony will mark the completion of two decades of dedicated work to control the threats that the dump site posed to public health and the environment. During the ceremony the City of Amsterdam will officially return the polder to the neighbouring village of Broek in Waterland and the natural landscape of Noord-Holland province. The residents of Broek in Waterland were the most directly affected group facing threats to health from hazardous waste at the site. With the remediation works completed these threats are under control. The City of Amsterdam has great plans for the Volgermeerpolder area and as early as April 2011 the site will be opened as a wetland nature reserve open to the public. The local authorities financed 10 percent of the total remediation costs, while the Ministry of Housing, Spatial Planning and the Environment covered the remaining 90 percent.
Growing fear of a looming environmental and social disaster resulted in a complete halt to waste disposal at the site in 1980. It was thought to be only a matter of time before toxic waste from the heavily polluted Volgermeerpolder site would spread uncontrollably into the environment – a true chemical time bomb. Plans were made and measures were taken over a period of two decades, but no comprehensive approach was designed and adopted and thus the time bomb continued to tick. Today, the situation looks far healthier. Under the name of Adviescombinatie Volgermeerpolder (ACV), consulting engineers Tauw and Witteveen+Bos joined forces in 2001 to design and supervise remediation of the site. During the remediation they developed the ‘natural cap’ concept, a sustainable solution with huge potential for dump site remediation, both in the Netherlands and in other countries.
Since Tauw and Witteveen+Bos were commissioned to design a top cover for the Volgermeerpolder site, an intricate process of design, study, testing and construction has evolved. Gradually, traditional approaches to isolation and remediation of the disposal site were revised. This process was enhanced by the ongoing discovery of the unique features of the local soils and the power of natural processes. Insight was generated into the principles and processes at play, and over time this knowledge was used in shaping and re-shaping the design of safe waste isolation at the site.
Situations like the one at Volgermeerpolder exist in many countries across the globe. Countries struggle with the legacy of industrial development. Technological advance has been tremendous over the past centuries. But government policymakers and modern industries only recently started to develop ecologically sound strategies to minimise and handle industrial waste caused by production processes. Extensive remediation programmes got underway in the 1970s to remove the threats of hazardous dump sites. Relatively new trends in waste management are Green Remediation and Natural Cap. Natural resources offer great potential to contain and even decompose chemical waste. In the remediation work at Volgermeerpolder, for instance, local peat lands exhibited excellent containment capabilities. Using peat instead of expensive construction materials in the remediation design resulted in significant reductions in public expenditure. The concept of the ‘natural cap’ means that the pollutants are contained by natural vegetation and associated processes. In the case of the Volgermeerpolder site, this is accomplished by creating a living peatland (moors and bogs) on top of the plastic foil that is used to cover the dump site. By the time the foil deteriorates, the newly formed peat bog will assume the functions of the foil. The project adopted a more integrated approach of nature development, wetland ecology and dump site remediation, in which remediation specialists worked together with hydrological, biogeochemical and ecological experts. Also, the project has become a very interesting national research site for peat development and recovery. This is very important for the low-lying Netherlands, where oxidating and vanishing peat soils accelerate lowering surface levels.
To mark the end of the Volgermeerpolder remediation and to focus on future Green Rehabilitation opportunities, ACV has pleasure in inviting international experts and stakeholders to take part in the 2011 Amsterdam Natural Cap conference and submit their conference papers. The main themes of the conference are:
- Sustainable waste management
- Green rehabilitation
- Wetland ecology
- Innovative techniques in remediation projects
- Sustainable management of Persistent Organic Pollutants (POPs)
