Recycling construction waste instead of landfilling it
The Department of Construction wants to orient the guidelines for handling construction waste even more strongly towards the circular economy. If as much construction waste as possible is reprocessed into building materials, this conserves natural resources as well as the scarce landfill capacities in the canton.
In the canton of Zurich, around 1 million tonnes of waste end up in a landfill each year. Most of this comes from construction activities – even though a large proportion of all construction waste is already used as recycled building material, for example in road and earth construction or for the production of recycled concrete. Landfill capacities in the canton of Zurich are scarce, and the construction of new landfills is becoming increasingly costly and difficult. The Department of Construction therefore wants to adapt the specifications for the treatment and recycling of construction waste with the aim of ensuring that in future even more waste is returned to the material cycle and does not end up in a landfill. This will also conserve natural resources.
Recycling up to 100,000 tonnes of additional waste per year
By far the largest part of the waste produced during the construction of buildings, roads and infrastructure is excavated material, i.e. soil and rock. If this is contaminated by pollutants, it must first be treated in a soil washing plant or a thermal plant before it can be recycled as construction material. Up to now, the Department of Construction has stipulated that at least 50 per cent of excavated and excavated material with low and low levels of pollution must be treated during excavation work. This quota is now to be increased to 75 per cent. This would mean that between 80,000 and 100,000 tonnes of polluted construction waste could be treated each year and returned to the material cycle as recycled construction materials.
Dismantling material only in exceptional cases directly to landfill
The demolition or conversion of existing buildings also generates around 2.5 million tonnes of construction waste per year in the Canton of Zurich. Of this, about 90,000 tonnes are deposited directly in a landfill. In future, only those demolition materials that are explicitly listed will be allowed to go directly from the construction site to a landfill. This list includes materials for which no recycling process exists to date, such as ceramics, porcelain or expanded clay. All other deconstruction materials must first be taken to a sorting or processing plant. This new regulation is intended to ensure that demolition materials are reprocessed into new building materials wherever possible.
The specifications for the recycling of construction waste are laid down in a guideline (“Treatment rule for contaminated construction waste, bullet trap material and demolition materials”), which must be applied to construction projects in the canton of Zurich. The Construction Directorate has submitted the adaptation of this guideline to the stakeholders concerned for comment by the end of September.