When asked about what he finds interesting about the techniques in this edition, Volkering mentions stimulation of natural processes in order to break down contamination. One of the ways to achieve this, is by introducing oxygen into the soil. This ensures bacterial activity that can break down oil contamination, for example. But the use of trees appeals most to him. Volkering: “Trees generate oxygen, which makes for a more active biological life around the roots. That is how trees can help solve contamination. It is a relatively new in situ method that is far less intensive than other methods.”

“The Netherlands became the first country in the world to structurally clean the soil, simply because we had to reuse our surface area.”

Becoming a pioneer

Despite the fact that the Netherlands is a small country, we are pioneers in the field of soil remediation. There is lot of interest from abroad in this specialism by Tauw. Volkering explained the development: “In the past, our soil was not regarded as something that needed protection. There was a gas factory in every city, and waste was simply dumped in large pits. We also used to build new neighbourhoods on sites that had previously been used as landfills. This caused people to get sick. But because of the limitations of our surface area, building elsewhere was usually not the most obvious option. This resulted in the Netherlands becoming one of the first countries in the world to structurally clean its soil. That is how we amassed our current experience in soil remediation.”

International perspective on soil

Although Tauw's soil specialists are most experienced with soil in the Netherlands, international colleagues where also involved in the creation of the book. The reason for this is that the soil found in the Netherlands is different from that in many other countries. Volkering explained: “Our soil contains a lot of peat, sand, and clay. It is mostly sediment brought down with the waters of the Rhine that has settled. The soil of the countries around us usually contains more rock. Substances behave differently there, it is a different type of ‘black box’. That is why we also focused a lot on other soil types. This makes the book of interest for professionals at home and abroad.”

The completely revised edition of In Situ Soil and Groundwater Remediation: Theory and Practice was published in May 2018. The book is written in English