What does Z.1.1 mean? Soil classification simply explained

Not all soils are created equal — and that is crucial for your construction project

When excavating excavation pits, pipeline ditches or road surfaces, the question sooner or later arises: Where to put the soil? And above all: How is it legally classified? Here comes the so-called Z classification In play — a central system for evaluating the environmental compatibility of mineral soil material.

One of the most important categories: Z.1.1. In this article, we explain what Z.1.1 means, when it becomes relevant and what construction companies and waste disposal companies need to consider.

What is the Z classification anyway?

The Z classification is part of “Decree for the recycling of soil material and construction waste”, often also as Construction waste decree referred to. It is used for the legal classification of Excavation materials after their exposure to pollutants — and therefore the question of whether a soil utilized, treated or deposited must be.

The most important classes are:

• Z.0 — unpolluted soil material, directly recyclable
• Z.1.1 — low-load material, still recyclable
• Z.1.2 — material subject to higher loads, can only be used with conditions
• Z.2 — heavily polluted, not recyclable, subject to landfill

What exactly does Z.1.1 mean?

The classification Z.1.1 stands for slightly polluted soil, who may be recycled without prior treatment under certain conditions — for example in road and civil engineering, landscaping measures or to fill up land.

Typical characteristics of Z.1.1 soils:

• The soil contains slightly increased pollutant levels, e.g. due to previous use or environmental influences.
• The burden is below the limitsthat would require separate treatment or landfilling.
• It may no contaminants such as plastics, glass, metals or organic materials.

Z.1.1 material may therefore recycled to a limited extent will — but only if the framework conditions are right and the material has been tested accordingly.

How is the Z.1.1 classification determined?

The classification is carried out by a analytical investigation of the soil material. For this purpose, a Sampling in accordance with LAGA PN 98 carried out, followed by an analysis in an approved laboratory.

Among other things, the following are tested:

• heavy metals (e.g. lead, cadmium, mercury)
• Polycyclic aromatic hydrocarbons (PAH)
• Mineral oil hydrocarbons (MKW)
• pH value, conductivity, sulfate, chloride

Only if all limits of Z.1.1 are met, the land can be classified in this category and recycled accordingly.

What happens with Z.1.1 soil material?

With RMS Remake Soil GmbH Let's accept Z.1.1 material and transfer it to the material recycling to — e.g. by:

• Preparation for liquid soil
• Reuse as backfill material
• Use in Earth and road construction

This means that the material is not only used sensibly, but also saves resources and landfill space.

Benefits of using Z.1.1

• cost savings compared to landfilling
• Conservation of resources through recycling
• Legally secure solution with documented analytics
• Reducing truck trips and CO₂ emissions
• Integration into sustainable building material cycles

When is Z.1.1 relevant to your project?

The Z.1.1 classification always plays a role when you Excavate larger quantities of soil and must check Whether recycling is possible — e.g. in the case of:

• Sewer or pipeline construction
• Excavation pits and earthworks projects
• Dismantling and remediation of contaminated sites
• Road construction and terrain modelling

RMS supports you with sampling, analysis and legally compliant recycling.

Conclusion: Z.1.1 — a key to sustainable land use

Classification as Z.1.1 is not an obstacle, but a Opportunity for resource-saving recycling. With the right analysis, advice and logistics, this material can be kept in circulation effectively and economically — instead of being deposited expensive and unnecessary.

Would you like to know whether your soil can be classified as Z.1.1?

We help you with classification, laboratory analysis and recycling — professionally competent, reliable and sustainable.

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