Contaminated land: what a buyer inherits

The duty follows the land

German soil protection law does not impose responsibility only on the polluter. Federal law sets the owner-liability rule. State law governs the register and the responsible authority, while a municipal by-law can affect local records and permits. § 4 BBodSchG places the duty to avert and remediate harmful soil changes on the person who caused them, on their universal successor, and equally on the current owner of the plot and on whoever has actual control of it. Fault is not required, and the fifty-year-old fuel tank buried by somebody long dead becomes your problem on the day the land register is changed.

That is the single fact that makes contamination different from most purchase risks. A defect in a building is priced or repaired. Contamination is a public-law duty owed to the authority, enforceable against the owner, and no clause in a purchase contract removes it. What a contract can do is give you a claim against the seller afterwards, which is worth exactly as much as the seller's solvency.

The two statutory starting categories

Which type of contaminated site?

1. AltablagerungClosed waste-disposal or waste-deposit site
2. AltstandortClosed installation that handled hazardous substances

Source: BBodSchG § 2(5); checked August 2026

What counts as an Altlast

§ 2 BBodSchG defines two categories. Altablagerungen are closed-down waste disposal sites and places where waste was deposited. Altstandorte are sites of installations that have been shut down and where hazardous substances were handled. Either becomes an Altlast where harmful soil changes or other dangers for individuals or the general public arise from it.

The definition matters because the suspicion comes before the proof. A site on the register as altlastverdächtig has a documented history and no confirmed contamination, and many rural parcels sit in that state. Suspicion is enough to stop a bank, to trigger an investigation order and to change a price, so a buyer needs to know which of the three positions a plot is in: clean, suspect, or confirmed.

Start with the site history. A GrundCheck preflight report shows the parcel and its surroundings, which is the context every contamination question is asked in. Check a parcel.

Regional legacies of contaminated land

Military, agricultural, industrial or mining use, and a history of dumping, are screening categories. Check them where the parcel history or local records indicate a possible risk.

• Soviet and NVA military sites. Former military regions carried garrisons, airfields, tank ranges and fuel depots. Kerosene and diesel plumes under former airfields are the classic case.
• Agricultural collectives. LPG yards mean fuel stores, workshops, pesticide sheds and dips, frequently unlined and rarely documented.
• Industry and mining. Lignite regions carry their own hydrology and ground problems, and small works and gasworks are scattered across the country.
• Wild tipping. Rubble, asbestos sheeting and household waste dumped in pits and ditches in the 1990s, which turns up in the first trial pit.

Unexploded ordnance is a separate question

Kampfmittel are not covered by soil protection law and are handled by their own service. The responsible state ordnance service answers requests about whether a parcel lies in an area suspected of ordnance (building in ordnance-suspect areas).

Given the fighting of 1945 across Germany, a large number of parcels are affected. The enquiry is straightforward, it is answered per parcel, and for a suspect area the building authority will normally want a clearance certificate before construction. Costs of investigation and clearance fall on the builder, and they can be substantial on a large footprint. Make the enquiry before the offer, not before the excavation.

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The register, and who holds it

The competent state keeps a register of contaminated and suspect sites under its state soil-protection act. The lower soil protection authority at the Landkreis holds it for its area, and the state environment agency works at state level.

Ask the Landkreis in writing, quoting Gemarkung, Flur and Flurstück (cadastral parcel), whether the parcel is recorded as an Altlast or as altlastverdächtig, whether any investigation has been carried out, and whether any restriction or order attaches to it. Ask about the neighbouring parcels too, since a plume does not stop at a boundary. The answer is a document for the file, and the fee is modest.

What an empty register does not prove

A register entry needs somebody to have noticed something. Sites that were never reported, never investigated and never complained about are simply absent, and the register was built up over decades from records that were themselves incomplete.

So the enquiry is a first step and not a clearance. Add the historical reading: old aerial photographs from the responsible state survey, the municipality's memory of what stood on the plot, and a walk over the ground looking for made ground, unexplained hard standing, rubble, oil sheen in a ditch and vegetation that stops for no reason. A parcel with a clean register entry and a former workshop yard visible on a 1993 aerial photograph is a parcel to investigate.

How an investigation runs

The technical review often begins with a historical desk study of the site history, old maps and photographs, register entries and other available records. Ask a qualified consultant for a parcel-specific scope and fee. The study may show whether intrusive investigation with boreholes and samples is warranted, but it does not itself prove that the soil is clean.

Where it does not, a technical investigation follows: trial pits, boreholes, soil and groundwater samples, and laboratory analysis against the trigger and action values in the Bundes-Bodenschutz- und Altlastenverordnung, whose current version has applied since 1 August 2023. This is a four to five figure exercise depending on the number of sampling points, and it is the stage where a purchase is either priced or abandoned. § 9 BBodSchG lets the authority order such an investigation where a suspicion exists.

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Where owner liability stops

The owner's duty is not unlimited. In a decision of February 2000 the Federal Constitutional Court held that a remediation duty imposed on an owner purely because they own the land can become disproportionate, and that the value of the plot after remediation is generally the reference point for the limit. The limit is weaker for an owner who knew of the contamination when buying, or who accepted the risk deliberately.

Read the second sentence twice. A buyer who signs after being told about the problem, or who chose not to look, is precisely the person the exception is aimed at. The protection exists for the unlucky owner, not for the one who bought a suspect plot cheaply and hoped. Full remediation costs on a moderate parcel run into six figures, so the difference is not academic.

Claims between the responsible parties

§ 24 Abs. 2 BBodSchG gives whoever carried out the remediation a claim for contribution against the other responsible parties, with the share depending principally on who caused the contamination. That is the route by which an owner who has paid can reach the polluter.

Two limits apply. The claim is time-barred three years after the claimant knew of the obligation and the person liable, and in any event thirty years after the measure was completed. And it requires a solvent defendant. A collective farm dissolved in 1991 and a garrison that left in 1994 are not defendants. In practice the owner who pays usually stays paid, which is why the check happens before the signature.

Asbestos, demolition waste and old building materials

Contamination is not limited to what lies beneath an empty field. Existing buildings can carry their own disposal risk. Corrugated asbestos-cement sheets on a shed roof, facade boards and old drainage components need controlled removal by a suitable contractor. Old mineral wool may contain hazardous fibres, while layers of paint can contain lead or other substances that make ordinary demolition handling inappropriate. A former heating installation may also leave an oil tank, contaminated pipework or an oil-stained bund in a cellar. Those materials need to be identified before a machine starts pulling the building apart, and the clearance work itself has its own seasonal and permit constraints, set out in the permit guide.

Demolition creates several waste streams, not one pile of rubble. Clean mineral waste, mixed construction waste, treated timber, asbestos and contaminated soil follow different transport and disposal routes, with different documentation and landfill charges. A contractor's headline demolition price may exclude sorting, specialist packaging, laboratory classification, haulage and disposal. On a difficult site, disposal can cost more than the demolition itself, especially where a large volume of suspect material is mixed together or the nearest suitable facility is far away.

A material survey before demolition is usually cheaper than discovering the problem once the machines are on site. It can map asbestos-containing products, sample suspicious coatings and insulation, identify the old oil system and separate clean material from waste requiring special handling. The result gives a tenderer a defined scope and gives the buyer a documented basis for negotiating the price. It also reduces the chance that a worker, neighbour or waste carrier is exposed because the building was treated as ordinary rubble.

From suspicion to a defensible finding

1. Register enquiryEntry or suspicion
2. Historical desk studyPast use and aerial imagery
3. Technical investigationBorehole, sample and laboratory
4. Risk assessmentSoil, human and groundwater pathways
5. Remediation or containmentMeasure agreed with the authority

Source: BBodSchG §§ 2, 4, 9 and 13 plus BBodSchV; checked August 2026

What the contract can and cannot do

A purchase contract cannot transfer the public-law duty; the authority still addresses the owner. What it can do is allocate the money, and three clauses are worth having where any doubt exists.

• A specific warranty that the seller knows of no contamination and of no register entry, replacing the standard exclusion of liability, which otherwise covers exactly this.
• A retention from the price held with the notary until an investigation is completed, or a condition making completion depend on its result.
• An indemnity for the cost of remediation, with a figure, since an unlimited indemnity against a private seller is not worth more than a limited one.

The seller's disclosure duty runs alongside. Concealing known contamination is fraudulent misrepresentation and defeats an exclusion of liability, but proving what the seller knew is a lawsuit, and a lawsuit is not a remediation budget.

Groundwater, and why it makes the problem larger

Many low-lying regions have a high water table. A contaminant that reaches groundwater stops being a local problem: it moves, it affects neighbours, it brings the water authority into the matter, and remediation shifts from excavating soil to pumping and treating water over years.

That is why the investigation samples water as well as soil, and why the position of a plot relative to a known source matters as much as its own history. A clean parcel a hundred metres downgradient of a former fuel depot deserves the same enquiry as the depot itself. § 13 BBodSchG governs the remediation planning that follows on larger cases.

What the checks cost against what they save

Compare written quotations with the purchase price and the possible measures, but do not infer the investigation fee from the land value. The consultant should state what records, site work, sampling and laboratory analysis the quotation includes.

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Three mistakes that cost real money

Treating an empty register as proof of clean ground. The register records known or suspected sites, not every historic use. A former workshop, farmyard, filling station or informal dump may be missing because nobody reported it or because the records were never connected to the parcel. A clean reply should therefore lead to a history check, not end the enquiry. Old aerial photographs, a site walk and a short desk study can reveal the clue that an administrative search could not.

Relying on the standard exclusion of liability in the deed. That wording is not a specific statement that the seller knows of no contamination. It may leave the buyer with the public-law duty and no practical claim for the investigation or clean-up. Ask for a concrete warranty covering register entries, known uses, tanks, spills and prior investigations, with a remedy that can be enforced. The seller's financial position still matters, but precise wording is a better starting point than assuming the boilerplate protects the buyer.

Starting earthworks without asking about Kampfmittel. A parcel can look ordinary and still lie in an ordnance-suspect area. If excavation finds ammunition, work stops, the area must be secured and clearance may require specialist investigation. Idle machinery, delayed trades and a halted financing schedule can cost more in days than a parcel enquiry costs in advance. Ask the Kampfmittelbeseitigungsdienst before committing to excavation, and build any clearance condition into the purchase and construction timetable.

Before the notary appointment

• Written answer from the Landkreis on the register, for the parcel and its neighbours.
• Written answer from the Kampfmittelbeseitigungsdienst.
• Historical aerial photographs, and the municipality's account of what stood there.
• A desk study where the history shows anything industrial, agricultural or military.
• A specific warranty in the deed, since the standard exclusion of liability covers contamination.
• Money held back, or completion made conditional, wherever an investigation is still running.

Ask the ground questions before the price is fixed. Order a GrundCheck preflight report and go into the register enquiries knowing exactly which parcel and which surroundings to ask about. Check a parcel.

Where these rules are written

• Definitions and duties: § 2, § 4, § 9, § 11, § 13 and § 24 BBodSchG.
• Values and procedures: BBodSchV, in force in its current version since 1 August 2023.
• State sources: the state soil-protection act, the state environment agency, and the Kampfmittelbeseitigungsdienst.

The state comparison cites Art. 3 BayBodSchG; § 6 BlnBodSchG; § 29 BbgAbfBodG; § 10 BremBodSchG; § 5 HmbBodSchG; § 7 and § 8 HAltBodSchG; § 6 NBodSchG; § 8 LBodSchG NRW; § 9 and § 10 LBodSchG Rheinland-Pfalz; § 21 BBodSchG and § 3 and § 4 UIG; § 5 BBodSchG; and § 7 ThürBodSchG.

• Historical imagery and parcel data: LGB, GEOBROKER, state cadastral viewer.

Rules and figures were checked in August 2026. This is general information for buyers, not legal or technical advice on your parcel. Read next: flood and nature risk, the due diligence checklist and land value.

Contamination is one of three ground risks worth separating: old mining and ground damage, the ordnance check before a purchase.

What differs between states

Each state names its contaminated-land register and competent soil authority. A state portal is a screening source; the plot-specific written reply remains decisive.