Environmental Law · Sub-area
Contaminated Land
Declaring land as contaminated triggers remediation obligations that can reach millions of euros. Three parties can be declared liable: the polluter, the current owner and former owners. The defence must begin at the hearing stage, before the declaration becomes final.
Regulatory framework: Law 22/2011, RD 9/2005 and Law 26/2007
The legal regime for contaminated land in Spain combines three complementary regulatory instruments. Law 22/2011 on Waste and Contaminated Land establishes the declaration procedure, the liability regime and the reporting obligations for operators of potentially polluting activities. Royal Decree 9/2005 defines the activities whose operation may cause soil contamination (Annex I), the reference levels below which land is considered fit for its intended use (Annex V), and the content of the soil status reports (IPE) that Annex I activities must submit periodically.
Law 26/2007 on Environmental Liability introduces the principle of strict liability for operators of Annex III activities — those considered most hazardous — removing the need to prove fault or negligence to impose the remediation obligation. For activities not included in Annex III, liability remains fault-based, with the implications this has for the defence.
The power to declare land contaminated lies with the regional governments, which have developed their own regulations with criteria and procedures that differ between territories. MITECO maintains the National Inventory of Contaminated Land, publicly accessible, which compiles the regional declarations.
Liability regime
The three liable parties
Law 22/2011 and Law 26/2007 establish a tiered joint-and-several liability system. The authorities may pursue any of the three parties, without prejudice to subsequent recovery actions between them.
Primary liability
The polluter
The party that carried out the activity that caused the soil contamination, even if no longer the operator of the facility or the landowner. Liability persists regardless of how much time has passed since the activity ceased. Law 26/2007 imposes strict liability for Annex III activities (the most impactful), removing the need for fault.
Subsidiary liability
The current landowner
The owner or possessor of the land when the proceedings are opened, even if they did not carry out the polluting activity. Their liability is subsidiary to the polluter's, but the authorities may pursue them directly if the polluter is unknown, insolvent or unidentifiable. In M&A transactions, this risk must be quantified before closing.
Exceptional liability
Former owners
Former owners can be declared liable if they knew or should reasonably have known of the contamination at the time of transfer and did not disclose it to the buyer, or if the transfer was made to defraud creditors or evade liability. Wilful concealment of the contamination may also constitute a criminal offence.
RD 9/2005 · Annex I
Potentially Soil-Contaminating Activities (APCS)
Companies carrying out Annex I activities under RD 9/2005 must submit periodic soil status reports (IPE) to the region and to MITECO. Non-compliance is a serious infringement under Law 22/2011.
Refineries and petrochemical plants
Coking plants and steel mills
Waste management facilities
Airports and commercial ports
Mining operations and extractive industry
Chemical and pharmaceutical production plants
Facilities with Integrated Environmental Authorisation (AAI)
Petrol stations, fuel storage and distribution
HowTo: step by step
Contaminated land declaration procedure
Under Law 22/2011 and RD 9/2005. The most effective defence is mounted at stages 3 and 4, before the declaration becomes final.
Activation of the procedure
The region opens the file ex officio (following a complaint, inspection, or IPE notification exceeding reference levels) or at the request of the owner, the liable party, or the affected landowner.
Preliminary investigation and risk assessment (ACR)
The region orders an exploratory investigation of the soil and groundwater. If the results exceed the generic reference levels under RD 9/2005, a specific Quantitative Risk Assessment (ACR) is required for the land use in question.
Proposal to declare the land contaminated
If the ACR confirms an unacceptable risk, the environmental authority issues a declaration proposal delimiting the affected perimeter and identifying the liable parties. This is the moment to review the methodology and challenge the perimeter.
Hearing stage
Interested parties have the right to a hearing. This is the key moment to challenge the ACR, question the perimeter, argue the absence of a causal link, or identify the actual polluter. A solid defence at this stage can prevent the declaration or significantly reduce its scope.
⏱ Usual deadline: 15-30 working days
Formal declaration and registry effects
The region issues the declaration decision. It is recorded as a marginal note in the Land Registry and in the National Inventory of Contaminated Land (MITECO). It creates the immediate obligation to draw up a decontamination plan.
Decontamination plan
The liable party draws up the plan with soil quality targets, remediation techniques, a timeline and a monitoring system. The region approves or amends it. It can be challenged if the requirements are disproportionate or technically questionable.
Declaration of non-contaminated land
Once the plan has been executed and the soil quality targets verified by the region, a declaration of non-contaminated land is issued and the registry entry is cancelled.
How we can help
Contaminated land services
Environmental due diligence in M&A
Review of the land's use history, searches for contaminated land files in regional inventories and at MITECO, analysis of IPE reports, and assessment of potential liabilities before closing.
Defence in the declaration procedure
Representation at the hearing stage, challenging the risk assessment methodology, questioning the delimited perimeter, identifying the actual polluter, and a strategy for allocating liability among the three obliged parties.
Appeals against the declaration
Administrative appeal and judicial review against the contaminated land declaration decision. Also challenging the approval of the decontamination plan where its requirements are disproportionate or technically questionable.
Recovery action between liable parties
Once decontamination works are completed, assisting the subsidiary owner in pursuing a recovery action against the actual polluter to recoup costs incurred. Coordination with technical experts to quantify the damage.
Frequently asked questions about contaminated land
Who is liable for decontaminating contaminated land in Spain?
Law 22/2011 and Law 26/2007 establish three jointly and severally liable parties: the polluter (who carried out the polluting activity), the current landowner (owner or possessor at the time of the declaration) and, in certain circumstances, former owners who knew or should have known of the contamination. The authorities may pursue any of them.
Which activities must report the soil status to the authorities?
Activities under Annex I of RD 9/2005 (potentially soil-contaminating activities, APCS) must submit periodic status reports (IPE). The Annex includes refineries, chemical plants, waste management facilities, airports, ports, mining operations and other high-impact industries. Non-compliance is a serious infringement under Law 22/2011.
Can the buyer of contaminated land be declared liable?
Yes. The current landowner is subsidiarily liable regardless of who caused the contamination. To mitigate this risk, it is essential to carry out environmental due diligence before signing and to include indemnity and escrow clauses in the SPA. Buying land without knowing its environmental status can create a hidden liability worth millions of euros.
How is the contaminated land declaration challenged?
The decision can be appealed through an administrative appeal (1 month) or judicial review (2 months). The most frequent grounds are: incorrect risk assessment methodology, excessive perimeter delimitation, absence of a causal link with the appellant's activity, or procedural defects during processing.
What effect does the contaminated land declaration have on the transfer of the property?
The declaration is recorded in the Land Registry as a marginal note, making it enforceable against third-party buyers. The seller is legally required to disclose it to the buyer before the transfer (art. 33 Law 22/2011). Failure to do so can result in the contract being voided and liability for damages caused to the buyer.