Contaminated site

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Improper storage on an industrial site

In environmental protection and spatial planning, the term contaminated site refers to a delimitable part of the earth's surface which, as a result of previous human activities , exhibits changes in the soil ( soil contamination ) or groundwater ( groundwater pollution ) that are harmful to health or the environment , whereby the minimum quality protected by legal norms is no longer given.

Running businesses are - at least in the industrialized world - mostly subject to strict environmental monitoring , so that no contaminated sites should accumulate.

Legal definition


In Germany, Section 2 (5) of the Federal Soil Protection Act (BBodSchG) contains the following legal definition

"Contaminated sites within the meaning of this law are

  1. decommissioned waste disposal facilities and other properties on which waste has been treated, stored or deposited ( old deposits ), and
  2. Plots of decommissioned plants and other properties on which environmentally hazardous substances have been handled, with the exception of plants whose decommissioning requires a permit in accordance with the Atomic Energy Act ( old sites ), which cause harmful soil changes or other dangers for the individual or the general public. "

Not all soil contamination is a legacy. If there are indications of contamination, for example due to use by an environmentally relevant company or the filling of a gravel pit with undocumented material, the area is initially designated as a suspected contaminated site and examined in more detail. For this purpose, a service provider is usually commissioned with a detailed historical survey of the use of the property, and the pollutant content of suspicious property areas is clarified by means of drilling and chemical analysis.

Often, due to a lack of documents, it is no longer possible to determine whether an existing contaminated site was originally due to a permit issued at the time, or whether it is a wild garbage dump - especially since there used to be far fewer safety requirements in the area of ​​waste disposal or the processing of chemicals. This difference is irrelevant for the definition of the term contaminated site.

The classification as a suspected contaminated area or site contamination exceeds the after state law local government agency, such as the district government or the district office . The classification as contaminated site means that this area poses a risk. This must be remedied through appropriate soil remediation measures.


In Austria, the contaminated site remediation law defines :

"§ 2. (1) Contaminated sites are old deposits and old sites as well as soils and groundwater bodies contaminated by them, which - according to the results of a risk assessment - pose considerable dangers to human health or the environment."

Old deposits within the meaning of the law are “deposits of waste that have been carried out with or without authorization” (landfills), old locations are “plants in which environmentally hazardous substances were handled”. Contamination caused by emissions into the air ( air pollutants ) is not subject to the scope of the law, but to the Emissions Act Air 2018 (EG-L).

According to current interpretation, the term contaminated site means that it arises before this Act came into force (July 1, 1989) as well as its entry in the Altlastlastenatlas (public book; Altlastenatlas-Ordinance , Federal Law Gazette II. No. 232/2004; until it is determined in the suspected area register ). Other contaminated areas are commonly referred to as new damage and are clearly differentiated from the term contaminated site .

The reason is that the law is primarily aimed at financing the remediation or securing of a contaminated site, i.e. it deals with the questions of the liability of the former operator and / or landowner ( polluter and property owner liability ), because ultimately the federal government is liable for the remediation (§ 18 ALSAG; the competent authority is the governor ). Since the law came into force, there has been a clear regulation; in particular, the contaminated site contribution in waste management ensures financing even if the operating company is liquidated. The close link between the remediation of contaminated sites and land recycling is to be further strengthened with the 2019 amendment to the ALSAG.


warning sign

In Switzerland, the principles of the obligation to remediate contaminated sites ( disposal sites ( landfills ), operational and accident sites) in Articles 32c to 32e of the Environmental Protection Act and details in the ordinance on the remediation of contaminated sites ( Contaminated Sites Ordinance , AltlV) of August 26, 1998 . In Article 2 (3) (Terms) the latter defines contaminated sites as:

"Polluted locations in need of rehabilitation."

Such loads can z. B. as dust, as deposits or as seepage of harmful substances.

The Contaminated Sites Ordinance distinguishes between disposal sites (closed or still in operation landfills and other waste deposits ), operating sites (disused or still in operation facilities in which environmentally hazardous substances have been handled, including shooting ranges and areas ), and accident sites (Art . 2 Z. 1 AltlV). Swiss law does not differentiate between historical “old” loads and systems that are still in operation, but emphasizes their operational reliability. A distinction is made between the contaminated sites in need of remediation and contaminated sites by builders , where remediation only has to take place when the property is converted or new buildings are built (with different rules for bearing the costs for remediation measures).

Contaminated sites are differentiated in relation to recognized protected assets (air, surface and groundwater, soil fertility, directly affected human and animal health) in need of remediation (and thus also in need of monitoring), only in need of monitoring (without the need for remediation outside of construction measures) and sites neither in need of remediation nor monitoring . Explicitly no pollution and thus contaminated sites according to contaminated sites law arise from large-scale pollutant discharges such as dust along roads with heavy traffic or previously common agricultural treatment with copper-containing pesticides in vineyards or sewage sludge containing heavy metals for soil fertilization.

The polluter pays principle applies to the remediation of contaminated sites . Under certain circumstances, as a further development according to the police disruptor principle , the authorities can also oblige third parties such as the disruptor of the state (for example the property owner) to take measures or take these measures themselves (substitute action) instead of the perpetrator (behavioral disturber ).

Based on the Ordinance on the Charge for the Remediation of Contaminated Sites (VASA) is on movements of waste on a landfill , a landfill tax levied. The income from this incentive tax is earmarked for the investigation of polluted sites and the remediation of contaminated sites. The amount of the levy varies according to the type of landfill.

Impact pathways

Pollutants from contaminated sites can reach people in various ways and thereby endanger their health or even their life. For Germany, the limit values ​​according to the Federal Soil Protection and Contaminated Sites Ordinance (in short: Federal Soil Protection Ordinance ) apply to the following pathways

  1. Exposure pathway soil and groundwater → From the groundwater is obtained drinking water and feeds on the surface water .
  2. Effect pathway soil and useful plants → The useful plants take up the pollutants via the roots and store them in tubers (potatoes, beets) or leaves (in lettuce, spinach, cabbage). Fruits and leaves are contaminated by blown dust.
  3. Soil pathway → People come into contact with contaminated soil or ingest the pollutants through the lungs (dust in the air), the skin (gardening) or the gastrointestinal tract (small children who eat the earth).

Classification as contaminated site and registration

The processing and reuse of an area suspected of being contaminated can usually only begin once it has been clarified whether soil or groundwater contamination actually exists and to what extent the risks arise from these pressures.

To do this, it is necessary to obtain as much information as possible about the usage history of a property or an industrial plant and then evaluate it,

  • whether there is a significant probability of soil and / or groundwater contamination from the previous use of the old site,
  • in which parts of the total area such contamination can be expected,
  • which substance inventory comes into consideration with regard to environmentally hazardous substances and
  • what spatial expansion of these substances is to be expected.

If sufficient data and information on the suspected area are available within the scope of the recording, possible negative effects on the relevant protected assets (e.g. soil , water , human life and health) must then be shown in an initial assessment.

The results of the initial assessment will determine whether further investigations are necessary for the final risk assessment or whether there is already enough knowledge to prepare a remediation ( remediation investigation ) of the suspected area or the contaminated site in the next step .


The recording of suspected contaminated sites is well advanced in Germany; In doing so, more than 360,000 areas were recorded and documented in contaminated land registers at the district governments. The initial recording was generally based on historical research, in which businesses with suspicious activity and former sand or gravel pits were selected. An established suspicion of contaminated sites generally leads to a loss of value of the property, so that there is a need to clarify the suspicion with suitable investigations at the latest when there is a planned change of use or the intention to sell. Many contaminated site investigations are therefore triggered in the course of land recycling .

The investigation is regulated in the Federal Soil Protection Act and in the Federal Soil Protection Ordinance and takes place in a graduated order

  1. Sampling-free recording (phase 1) if there is an indication (old industrial wasteland as suspected contaminated site) through inspection, file research in the company or at the authorities, possibly also aerial photo evaluation or evaluation of other sources
  2. Orientation investigation (phase 2a): a first investigation by means of ramming soundings in suspected hot spots or in a wide-meshed grid over the area to be investigated. The assessment is based on the so-called test values ​​in the Federal Soil Protection Ordinance (BBodSchV). If the test value is found to be exceeded, the suspicion has become more concrete, and the
  3. Detailed investigation (phase 2b): The horizontal and vertical extent of the damage is investigated; if necessary, groundwater investigations are carried out. If the contamination found in the preliminary investigation only turns out to be a punctual excess, the suspected area is not automatically upgraded to a contaminated site.

However, if the area is declared a contaminated site by the responsible environmental authority after a risk assessment, the next step is to decide whether to remediate or secure the damage. For this are

  1. Weigh up possible rehabilitation and security procedures against each other according to feasibility and expected costs
  2. to carry out a remediation investigation for a preferred procedure selected as a result of the weighing up (phases 3a and b). The result then becomes
  3. the redevelopment planning is worked out with a specific time and budget.


In Austria around 70,000 old sites and deposits are known, of which only around 2% to 3% represent contaminated sites within the meaning of the contaminated site remediation law, which arose before July 1, 1989. As of January 1, 2019, 304 contaminated sites were identified in the contaminated site atlas , which is kept by the Federal Environment Agency , of which 164 were rehabilitated or secured, and 1895 areas in the suspected area register that still have to be assessed.

Since the contaminated site remediation law came into force, 10 million tons of contaminated sedimentation and subsoil material have been removed, and areas totaling more than 1000 ha have been remediated.


In Switzerland, the cadastre of polluted sites has been drawn up since the end of the 1990s and is operated jointly by the federal government and the cantons at the Federal Office for the Environment (FOEN).

There are a total of around 38,000 polluted locations, of which around 4,000 are likely to be in need of remediation (“contaminated sites” as defined by the law). Almost 40% of all polluted sites are dump sites, almost 50% operating sites, around 10% shooting ranges and ranges and around 1% accident sites. The investigations have not been completed; investigations into environmental impacts are being carried out at a total of 5,700 locations or will be tackled in the next few years. Around 2% of all locations are already being monitored, 5% have to be renovated.

The total area of ​​all recorded polluted locations is around 225 km 2 (this corresponds to the area of ​​the canton of Zug). The majority (two thirds) is in the central plateau with its dense population, one seventh (14%) in the Swiss Jura , the remaining quarter (23%) is spread across the rest of Switzerland.

Measures: Securing and remediation of contaminated sites

  • Security comprises the initial measures to prevent further emissions and contamination.
  • Remediation of contaminated sites includes:

Remedial measures are all measures that are suitable to restore a legally compliant condition. According to the claim of "healing" these can be:

  • Administrative measures, such as conversion of the area to a less sensitive use (see Building Use Ordinance ).
  • Safety measures, such as the installation of a structural barrier against the effects of pollutants.
  • Relocation, in which the pollutant-containing material is removed and reinstalled at another location, for example in a landfill .
  • Decontamination in which the pollutants are technically removed.
  • To take remediation without measures by carrying out the self-cleaning naturally through k ontrollierten n atürlichen R ückhalt or A BBAU of pollutants ( KNRA ), often with the English word m onitored N atural A ttenuation named ( MNA ). The only "measure" is to control changes in the pollutant content.

The success of the renovation must be proven with suitable measuring methods, possibly with recurring measurements (the permanent effectiveness of the security).

The so-called old armaments hold a special position. This refers to areas that were used for the production of military goods ( explosives ) or that were used directly by the armed forces or that were contaminated by the effects of weapons. An inventory in the mid-1990s recorded 3240 such areas. The special position is based on the fact that the Federal Republic of Germany is directly liable if there is evidence of a direct consequence of the war.

Decontamination measures are basically divided into

  • active procedures: such as pump and treat procedures ("pumping out and treating") or the introduction of substances or energy and treatment of mobilized pollutants;
  • passive processes: such as the installation of migration barriers for water or gas as well as the introduction of biologically, chemically or catalytically active materials into the subsoil, reactive walls .

They can be carried out on the contaminated site itself ( onsite ) - either by means of mobile treatment systems or without excavating the soil ( in situ ) - or offsite by transporting the contaminated soil to an appropriate soil treatment system.

Teaching and Research

At the BTU Cottbus there is a "Chair for Contaminated Sites". Until March 2012, the professor was Wolfgang Spyra . Since the 2013/2014 winter semester there has been a four-semester cooperative master’s program between the University and the Osnabrück University of Applied Sciences, “M. Sc. Soil, water, contaminated sites ”. The focus on "contaminated sites and soil protection" can be demonstrated here.


  • Hans-Peter Vierhaus: The Federal Soil Protection Act . Neue Juristische Wochenschrift (NJW) 1998, pp. 1262–1269.
  • Michael Bihler, Michael Koch, Wolfgang Mücke: Course book Altlasten - Law, Toxicology and Technology. 1st edition, Vahlen Verlag, Munich 2001, ISBN 3-8006-2764-7 .
  • Lothar Knopp, Eike Albrecht: Legacy law in practice. 2nd Edition. Verlag für Rechts- und Anwaltspraxis Herne, Berlin 1998, ISBN 3-927935-91-3 .
  • Ulrich Stottmeister, Erika Weißbrodt, Jörg Tittel: Natural self-cleaning: From the contaminated site to the lake. In: Biologie in our Zeit 32 (5), pp. 276-285 (2002), ISSN  0045-205X .
  • Thomas Wilrich: Contaminated Sites Liability - Official Disturber Selection and Private Law Agreements. In: Altlastenspektrum 2002, 257.
  • Wolfgang Kinzelbach, Axel Voss, Randolf Rausch: Contaminated Sites Manual of the State of Lower Saxony. Calculation methods and models. Material tape. Springer, Berlin 1996, ISBN 3-540-60755-2 .

Web links

Wiktionary: Altlast  - explanations of meanings, word origins, synonyms, translations




Individual evidence

  1. Law, contaminated site remediation law.
  2. To this in detail Hubert Reichl: Liability for contaminated sites. Austrian Water and Waste Management Association (ÖWAV), onA (2009), Liability for contaminated sites , III. Public liability issues relating to a property identified as a contaminated site , especially III.3. Public liability - using the example of a landfill (contaminated site) - AWG 2002 p. 4 ff ( pdf , on, accessed November 28, 2019).
  3. ALSAG amendment 2019 (87 / ME) . Parliamentary materials.
  4. a b c d e f g Status of contaminated sites handling in Switzerland. Federal Office for the Environment FOEN: Topic Contaminated Sites → Technical Information → Contaminated Sites Processing (as of April 30, 2019, accessed November 28, 2019).
  5. Progress in the remediation of contaminated sites. , Federal Environment Agency: News , March 26, 2019.
  6. Soil and contaminated site remediation in Austria: a success story. Federal Ministry for Sustainability and Tourism: (accessed November 26, 2019).
  7. Remediation of contaminated sites. Spectrum: Lexicon of Geosciences.
  8. Chair profile ( Memento from February 19, 2014 in the Internet Archive )
  9. btu Cottbus-Senftenberg: Chair Contaminated Sites ( Memento from April 12, 2013 in the web archive )
  10. Osnabrück University of Applied Sciences: Master's degree in Soil, Waters, Contaminated Sites ( Memento from February 1, 2014 in the Internet Archive )