Soil class Z2 - concerns when buying

Hello everyone,

we are currently considering buying a plot of land. A comprehensive soil survey is already available for this. Mixed samples were taken from six different, representative drilling points. According to the municipality, these reflect the entire soil in the new development area. Attached is the concerning mixed sample 3. This comes from three drillings.

Regarding arsenic, we are in a worrisome range that causes us concern.

1. Can one build here without concerns with regard to children? If they play outside, etc.? Is there a health risk?

2. What are the disposal costs? The house is supposed to be 10x10m and there is a height difference of 1m in this section. So one might need to remove about 90cm and backfill on one side and maybe 30-40cm on the other side and also backfill? Is that roughly correct with a 20cm thick concrete slab?
Does the local landfill accept this or is it possible that one has to drive far? What are the estimated additional costs?

Should one rather stay away from this?

We would appreciate feedback :) We are also very interested in explanations and interpretations of the sample :)

We will probably get arsenic on the property as well. As far as I could research, it is fairly harmless for the residents; root vegetables should just be washed properly.

Arsenic is somewhat more problematic for the builder’s wallet. Unfortunately, I still couldn’t find good figures. Where it can be stored and how much it will cost depends heavily on your construction site.

Z2 is already quite something. You should ask the local landfill whether/what they accept and how much it costs (also in relation to Z0, to get an impression of the additional costs). I can’t say to what extent arsenic is a problem for the residents. You have to research each contamination individually. Normally, simply walking on it is not a problem; for such cases, there are official orders for soil replacement or similar. But whether you should eat the berries from your own bush or the carrots ... the research will tell you that.

Hi,

for our current construction project we have a disposal price of approx. €60/m³ for LAGA Z2. This naturally depends on the type of contamination (here it is due to PAK). In addition, there are transport costs (always variable (included in the €60 here, as the transport distance is very short), since I do not know where a landfill is near you) and the costs for loosening the soil (here €16/m³). Added to this are estimated 15% business costs and then 19% VAT. With your assumption of 90 m³, that would be approx. €9,350 plus the costs for gravel. I currently don’t have a reasonable price for that. Filling sand is approx. €13/m³ plus business costs and VAT, and you can estimate the installation and compaction at about €10/m² (plus business costs and VAT).

Personally, I wouldn’t want to have such soil in the garden. Under the house, possibly with a protective strip, I think it is manageable. Obviously, groundwater washes out contamination, but for that groundwater would have to be present first and from how it sounds at your place, that is not the case.

So possibly, rather make an exchange in the garden and fill it with proper soil (which is also not cheap).

Best regards Jann