Sustainability and the environment

By cleaning up our world, and washing contaminated soil and incinerator bottom ash, we contribute to a sustainable society. Needless to say, complex, large-scale projects (link) also involve risks for the environment. That is why we are always extremely precise in our approach to our work. We comply with the legislation and regulations in the field of environmental risks. And we are always looking for ways of improving our environmental performance. The environmental management system we use in our work is certified (ISO 14001:2004).

Not only that: Boskalis Environmental is also one of the signatories to the National Raw Materials Agreement.


Incinerator bottom ash

In addition to the approach that is already in place involving the use of washed bottom ash as a filler material/subsurface for roads (which does not require any additional measures to prevent the leaching of metals), Boskalis Environmental also makes it clear how the washed bottom ash can be used as a raw material in more high-grade applications. The goal is to contribute to the circular economy (recycling raw materials as much as possible and in applications that are as high-grade as possible) and to reduce carbon emissions further.
The illustration below shows the useful role that the washing process for bottom ash can play.

Figure 1: Circular Economy by Ellen MacArthur Foundation

It can be concluded that waste (if combustible) will normally be incinerated at the end of the life cycle, with the underlying principle being to retain the raw materials in the 'technical cycle' as long as possible. In the past, bottom ash was used as a soil fill or in building products without being washed and there was therefore a risk of, for example, metals leaching. To prevent this happening, additional measures always had to be taken and the environmental problem could re-emerge in the longer term when new building work took place.

The ongoing research of Boskalis Environmental is part of the initiatives by all Dutch waste-to-energy plants and the Ministry of Infrastructure & the Environment as part of the Green Deal for incinerator bottom ash. The objective of this Green Deal is to make the application of incinerator bottom ash more sustainable. The ultimate objective of the initiative is to bring about the beneficial use of all bottom ash by 2020. This initiative contributes to the 'circular economy' by recycling the material in high-grade applications, using less raw materials and reducing the amount of waste produced.

The savings achieved with the metals obtained are due to the fact that no more primary processing is required of raw materials such as iron ore, bauxite, etc. And it is possible to use metals obtained during the 'secondary' process. The saving results from the fact that there is no need for primary extraction and processing. An additional advantage is, of course, that there is less land use and transportation because metals from the waste are returned to the technical cycle. The processing of bottom ash by Boskalis Environmental results in the recovery of significantly more metals from the bottom ash than previously and so a major contribution is made to both the circular economy and the reduction of carbon emissions.

For Boskalis Environmental, corporate social responsibility is not just about the final result, but also about the way we achieve it. We engage in business for economic reasons, with the appropriate attitude towards people, their surroundings and the environment.


CO2 Performance ladder

The role of carbon awareness in our corporate social responsibility will continue to increase in our organization in the years to come, with the reduction of carbon emissions being one of the concrete objectives. In this context, the energy management system used at Boskalis Nederland BV since 2011 has received certification from the CO2 performance ladder system ( In 2012, Boskalis Nederland BV reached level 5, the highest level on this ladder. Boskalis Environmental is covered as an entity by this CO2 certificate for Boskalis Nederland BV.