Contaminated Land Advisory Group: terms and definitions

List of terms and definitions as used within the context of Contaminated Land Advisory Group (CLAG) discussions.

This list of terms in common use within discussions at the CLAG is not meant to be exhaustive and can be added to as the workstream of the CLAG develops:

Assessment (action)

Is a remediation action rather than investigation and is the doing of anything for the purpose of assessing the condition of the contaminated land in question or the water environment affected by that land or any adjoining or adjacent land. (Paper SE 2006/44)


Land which has previously been developed. The term may cover vacant or derelict land, infill sites, land occupied by redundant or unused buildings and developed land within the settlement boundary where further intensification of use is considered acceptable. (SPP3 – consultative draft)

Contaminated land

Any land which appears to the local authority in whose area it is situated to be in such a condition, by reason of substances in, on or under the land that- a) significant harm is being caused or there is a significant possibility of such harm being caused, or; b) significant pollution of the water environment is being caused or there is a significant possibility of such pollution being caused. (Part IIA, EPA 1990) Such land must have been formally identified as such.

Derelict land

Land which has been so damaged by development that it is incapable of development for beneficial use without rehabilitation. Such land must currently not be used for the purpose for which it is held or a use acceptable in the local plan. Also land can be derelict if it has an un-remedied previous use which would constrain future development. (Scottish Vacant and Derelict Land Survey 2009)

Generic Assessment Criteria (GAC)

Scientifically based screening criteria, usually derived using CLEA. They can be used as a starting point in evaluating chronic risks to human health to human health from chemicals in soil. They provide an indication of the chemical concentration in soil below which the long term human health risks are considered to be tolerable or minimal. They do not represent the trigger for unacceptable intake and exceedence of a GAC does not necessarily imply significant possibility of significant harm.

Health Criteria Value (HCV)

A generic term used to describe a benchmark level of exposure to a chemical derived from available toxicology data for the purpose of safeguarding human health e.g. a tolerable daily intake.


Harm to the health of living organisms or other interference with the ecological systems of which they form part and, in the case of man, includes harm to his property. (Part IIA, EPA 1990)


Any detailed inspection of land by an enforcing authority carried out under its Part IIA duties.

Investigation / Intrusive Investigation

An investigation of land which involves actions going beyond simple visual inspection of the land, limited sampling or assessment of documentary information.


Fully defined in section 78A(7) of the EPA 1990, however it includes anything necessary to assess the condition of contaminated land, the water environment or adjacent land affected by it; works, operations or steps to contaminated land or waters to prevent, minimise, remedy or mitigate the effects of significant harm or significant pollution of the water environment or restoring the land or waters to their former state; and making subsequent inspections to keep the condition of the land under review. This term does not necessarily mean the removal or 'clean up' of contamination from the land.

Register (colloquially called the contaminated land register)

Public register required to be maintained by enforcing authorities under section 78A(R) of the EPA 1990 containing particulars relating to contaminated land which are specified to require to be included by the Contaminated Land (Scotland) Regulations 2000 (as amended 2005).


Combination of: the probability or frequency of occurrence of a defined hazard and the magnitude.


Programme of land redevelopment in areas of moderate to high density land use.

Significant harm

Defined in section 78A(5) and means any harm determined to be significant in accordance with the statutory guidance.

Soil Guideline Value (SGV)

Non statutory, scientifically based criteria for assessing the risk to human health from chronic exposures to chemicals in soil. Like GACs they do not represent the trigger for unacceptable intake and exceedence of an SGV does not necessarily imply significant possibility of significant harm.

CLAG list of terms and definitions.pdf


Email: Central Enquiries Unit

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