Case Study Landfill

A solar farm on a former landfill site requires a different approach than a solar farm on regular land. After all, you are usually dealing with a slope and a foil that may not be affected. This is not a problem for us. In March 2018, we were one of the first in the Netherlands to build a solar farm at the Avri landfill site in Geldermalsen. We recently completed solar park Fort de Pol in Zutphen. In addition, we are currently building at locations Wijdemeren and Farmsum. Through these cases we have built up a lot of experience. We would like to take you through the complexity of a solar park on a landfill using a number of practical examples.

Permit

The former landfill sites in the Netherlands can be roughly divided into two categories. Landfill sites that were closed before 1996 and landfills that were closed after that. Landfill sites that were still in use before 1996 are usually more heavily contaminated and fall under the Environmental Management Act (Wm). In practice, this means strict regulations and an aftercare regime for which the province is usually the responsible administrative body. The group still in use after 1996 are small, as more and more waste has been reused or incinerated since the 1980s. Most of the former landfills were therefore closed before 1996.

In many cases, a solar park requires at least an environmental permit under the Wabo. In addition to an environmental permit, a former landfill has an environmental permit. As a result, all other activities are subject to an environmental permit. The permit holder is often the municipality or province. Because permits cannot be stacked, the facility will have to be expanded. This involves far-reaching cooperation between the developer, the permit holder and the aftercare. It is therefore important to have intensive cooperation between these parties. Besides the public law part, there will also be private law agreements on the use and responsibility regarding the landfill.

Aftercare

When a landfill site is decommissioned, contaminated soil is left behind. To prevent exposure to or spread of contamination, measures are taken. This is called aftercare for residual contamination after soil remediation. The soil will be decontaminated before aftercare takes effect at a landfill site. Soil remediation does not have to mean removing the contaminated soil. Remediation can also mean controlling the contaminated soil. This means that the soil does not have to be excavated, but covering it with a clean layer may also be sufficient. Under the Soil Protection Act, the provinces and large municipalities are responsible for licensing and enforcement for soil remediation. In many cases, aftercare then also lies with the province or other administrative bodies affiliated with the province or municipality. Aftercare may be outsourced to a public party. Aftercare consists of monitoring to guard against possible spread of the contaminated soil. Aftercare can further consist of imposing a use restriction. All this is described in the aftercare plan.

Construction and construction

The subsurface of a former landfill site is composed of different layers. These layers can differ per landfill. Broadly speaking, the structure of a landfill is as shown in Figure 1. On top of the contaminated soil is a drainage layer and a covering layer. Further compression of the dirt under the cover layer releases gases and allows the soil to settle. The top layer is often lined with a turf that also serves a signaling function for the state of the liner. These processes and layers in the landfill make creating a solar farm on these lands challenging. The panels must be mounted in such a way that leaching from the turf is prevented and, in addition, there are restrictions regarding the depth that the soil may be disturbed, When mounting the panels, settling of the soil must also be taken into account. Another aspect that must be taken into account is the maximum amount of pressure that the structures may put on the landfill. All these aspects should be well coordinated with the relevant parties responsible for the aftercare of a particular landfill site.

Conclusion

Although former landfill sites present a challenge, Novar says they are also a prime location for solar energy. From the standpoint of dual space utilization and the use of marginal land, using former landfill sites is an efficient use of space. The after-care that lies on a site and technical modifications for the opstal offer a challenge, so technically, legally and environmentally it requires skillful and careful development.

This is an article from the Dual Use of Space theme. Want to know more? Also read how to turn a parking lot into a solar power plant.