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Contaminated soils: what the deed must say and the listing never does

A 2012 block built on an inventoried former landfill. A warehouse in a converted industrial estate. A parcel that in 1956 was a brickworks. None of this is illegal or necessarily dangerous — but it changes what you can do with the ground, what it costs to do it, and what the deed has to declare.

What the inventory is

The inventory is not a list of contaminated soils. It is a list of soils where a potentially polluting activity took or takes place: industry, landfill, petrol station, workshop, fill. Being inside means that before a change of use, an excavation or the end of the activity, the soil quality must be investigated and, where needed, remediated. In the Basque Country this is Law 4/2015, published by Ihobe (2022 edition); in Andalusia, REDIAM; nationally, Law 7/2022 on waste and contaminated soils, with the IED installations register and the landfill census.

What must be declared in the deed

National law (art. 98 of Law 7/2022) and Basque law (art. 17 of Law 4/2015) oblige the seller to declare in the deed whether a potentially soil-polluting activity has been carried out on the property. If the notary does not ask and the seller does not say, the declaration is missing — and the problem passes to the buyer. Ask for the declaration before you sign, not at the notary's.

What being inside implies

• For living in a flat already built on remediated soil: usually nothing, if the remediation was done and declared. Ask for the soil-quality declaration from the file.
• For a plot or warehouse: any excavation, change of use (industrial to residential, say) or end of activity triggers the legal procedure, which costs time and money and can end in an expensive remediation.
• For the price: industrial land "with residential potential" without a soil-quality investigation is worth less than the listing suggests.

How to check

In the Basque Country, the GeoEuskadi viewer carries the Ihobe inventory layer: find the parcel and see whether it lies inside a polygon and of what type (industry, landfill, fill). In Andalusia, the REDIAM viewer. In the rest of Spain, MITECO's IED register and landfill census give the large installations; for the rest, historic orthophotos are the best clue: what you can see since 1945 →

What the PropVer report does

It intersects the parcel with the Ihobe 2022 inventory (Basque Country) and REDIAM (Andalusia), with the European IED installations register and with wastewater plants; counts inventoried sites within 250 and 500 m (a dense industrial surrounding is information even if the parcel itself is not inventoried); and reads the orthophotos to say since when there has been activity on the parcel. If a layer does not exist in the region, it says so: "not consulted" never becomes "no findings".

Updated 2026-10-23.