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1. Introduction

1.1 Objectives and terms of reference
1.2 Environmental standards
1.3 Structure of the compendium of environmental standards (CES)

1.1 Objectives and terms of reference

The Compendium of Environmental Standards (CES) contains information about environmental standards that can be drawn upon for the purpose of estimating and evaluating projects' environmental impacts.

In its present form this volume already constitutes a source of basic information about a variety of specific standards. However, the number of standards described in full and the scope of the related information are still limited. This compendium should thus not yet be regarded as exhaustive, but rather as a manual still in the process of being compiled. It is structured so as to permit both the addition of further information to existing sections and the inclusion of new sections. The modular structure, the overall design and the design of the individual sheets will allow the work to be updated and supplemented as required.

1.2 Environmental standards

The term "environmental standards" refers in the broader sense to parameters, indicators and classification systems which can be used to monitor impacts on the environment, describe environmental quality or determine elements of these. In the narrower sense of the term, "environmental standards" can be taken as meaning

- parameters that can be used in formulating limit values, recommended values or other environment-related measurands, or

- the actual limit values, recommended values or specifically function-oriented measurands (limit values, recommended values, guide values, ecotoxic measurands etc.).

Environmental standards can relate to any element of the complex of ecological interrelationships and may be classified as pertaining to the individual components:

- Atmosphere (the envelope of air surrounding the Earth)
- Pedosphere/lithosphere (the soil covering the Earth/the Earth's crust)
- Hydrosphere (the aqueous vapour of the entire atmosphere and that part of the Earth's surface consisting of water)
- Biosphere (the Earth's life zone; habitat of flora and fauna)
- Anthroposphere (man's life zone; human habitat)

The operational starting points for standards are generally derived either from the type of influence exerted on the environment or from the requirements to be fulfilled by elements of the environment:

Influence categories

Standards pertaining to the release/discharge of pollutants/noise/heat and the use of environmental media (influences on the environment) relate to impacts originating directly from the projects under consideration.

1 Waste water: discharge of contaminated or polluted water into surface waters or into the groundwater.

2 Waste heat: discharge of heated water into surface waters or into the groundwater.

3 Emission: discharge of gases and dusts into the atmosphere; special emissions such as light, radioactivity, electromagnetic rays.

4 Solid wastes: production and dumping of waste materials, excavated material, sewage sludge, mining waste etc.

5 Chemical aids: introduction of chemicals into the environment for a specific purpose (e.g. pesticides and fertilisers, thawing salt etc.).

6 Changes in land-use: changing the existing surface cover or changing the purpose for which an area of land is used.

7 Removal of soil: elimination or relocation of the biologically active soil cover.

8 Action influencing the water balance: (quantitative water management); influencing or use of the available water supply for a specific purpose.

9 Action influencing the surface configuration: changes in orographic conditions (excavation and deposition); changes in the landscape.

10 Noise emission: emission of noise (outside enclosed spaces).

Environmental quality categories

Standards pertaining to environmental quality relate to elements and functions of the environment that are the subject of direct user requirements.

1 Air quality: requirements in respect of air purity and other parameters, e.g. as imposed by immission limit values.

2 Climatic situation: requirements in respect of the topoclimate in particular.

3 Noise situation: requirements in respect of absence of noise.

4 Available water supply: water needs (quantitative aspect).

5 Water quality: requirements in respect of water purity and condition/absence of harmful, undesirable substances, microorganisms and other parameters.

6 Soil quality: requirements in respect of the (physico-chemical and biological) condition of the soil.

7 Agricultural and forestry land: requirements in respect of land that can be used for producing food, wood and other forms of biomass.

8 Special biotope functions: requirements in respect of bioecological conditions (not covered by 1 to 6 above).

9 Food quality: requirements in respect of the absence of pollutants and pathogens from food and in respect of food quality from the nutritional-physiology viewpoint.

10 Special uses and functions: requirements in respect of specific conditions (not covered by the above), e.g. recreational use, protected-area status, landscape.


One question which arises in connection with environmental studies concerns the value of bioindicators. The term "bioindicators" refers to a wide variety of biological (as opposed to chemico-physical) methods for ascertaining environmental conditions. Bioindicators are used for aquatic ecosystems and feature in regulations laying down water standards. More or less standardised methods exist for ascertaining the immission or load condition of other media, although such methods are in general used on only a very limited scale in the Federal Republic of Germany. If it proves possible to develop bioindicator systems geared to practical requirements, however, it is likely that methods of this type will gain in significance.

Bioindicators impose special demands in terms of region-specific calibration and standardisation. It is above all with regard to the kinds of ecotope found in tropical zones, however, that a great deal of research, development and preparatory work is still needed before bioindicators can be regarded as ready for operational use, let alone used as standards. So far there is at any rate no compilation of bioindicators that could be used in environmental studies.

Excursus: The importance of standards

The first key task of a study for the purpose of estimating and evaluating environmental impacts is the value-free determination of a project's effects on the environment and the resultant or likely changes. However, the study cannot serve as a decision-making aid until the significance of these effects and changes has been evaluated. The criteria used in this evaluation must be derived in the final analysis from the demands which man requires the environment to fulfil, whether these be based on physiological, economic, ethical or other considerations. They are reflected among other things in the goals of the German Federal Government's environmental programme, which can be summarised as follows:

- to safeguard health and well-being against harmful environmental influences of anthropogenic origin.
- to preserve and improve the efficiency and usability of the natural household.
- to preserve the natural diversity and characteristic features of fauna, flora and landscape.

One way of concretising the above goals and criteria and translating them into operational terms is to formulate limit values and recommended values (referred to hereinafter as "standards"). In the past (and this will undoubtedly remain the case), every country went its own way in developing such standards with the result that there is today an immense variety of limit values, recommended values and guide values which differ not just in terms of the absolute value given (varying by factors of up to 1000), but also with regard to the related marginal conditions such as measuring technique, reference area and reference period, averaging method, pre-existing pollution level, binding nature etc., and therefore do not lend themselves to comparison.

This situation can be ascribed not only to the difficulty of laying down standards that can be justified from the scientific viewpoint and to the resultant need to combine scientific findings, economic and political interests, available measuring and monitoring techniques, the latest state-of- the-art and so on. It also stems from the fact that basic environmental-policy concepts vary from one country to another (depending on problem urgency and problem awareness, attitudes towards the environment, economic system, political decision-making mechanisms and many other factors).

Various aspects of this problem are outlined below:

- taking the example of cadmium, the wide variety of possible standards and the basic qualitative difference between emission standards and immission standards.

- taking the example of air quality management, the possible (necessary) coordinated application of different standards to achieve quality goals.

- possible political strategies for laying down emission standards.

Substance-specific standards (example: cadmium)

The wide variety of conceivable standards that can apply even to pollutants whose presence is relatively easy to ascertain can be demonstrated using the example of cadmium, a heavy metal. Figure a) is a highly simplified representation of the possible pathways taken by cadmium to reach the receptor, namely man. Each of the arrows constitutes a starting point for a wide variety of standards. This example clearly demonstrates that all standards which relate to those elements in the effect complex preceding uptake of the pollutant by the receptor serve the purpose of ensuring compliance with the receptor-specific standards. They should thus essentially be derived from the receptor's requirements, which in the case of man, for example, may vary considerably from one individual to another (differing degrees of sensitivity!) and from one country to another (e.g. different eating habits). As knowledge of the chain of effect is in most cases only fragmentary, the unreliability of a standard increases in proportion to its "distance" from the receptor. It follows that emission standards involve far greater factors of uncertainty than quality standards and this also explains why for the most part they are (indeed, have to be) laid down on the basis of criteria which have little to do with the pollutant's impact on the receptor.

Fig. a): Pathways taken by cadmium in reaching man

Standards for air pollutants

The most sophisticated air quality management systems, such as those in the USA and the Federal Republic of Germany, employ (along with other measures) a variety of coordinated standards in order to influence various stages of processes and mechanisms that may eventually lead to unwanted immissions and impacts.

They limit or regulate

- the composition of substances which can give rise to emissions when used for their intended purpose (product standards);

- the design and operation of plants, installations and equipment, with a view to minimising emissions (equipment standards);

- the emission of air pollutants into the atmosphere, by means of plant-specific and/or substance-specific regulations (emission standards);

- the atmospheric concentration or deposition of air pollutants; in this way the uptake of pollutants and their impact on specific acceptor groups are indirectly limited (immission standards , "ambient air quality standards"). As a particular pollutant may have different impacts on different acceptor groups, there may be different standards for one and the same substance.

Political strategies for establishing standards

A variety of different strategies is adopted in laying down emission standards. This can lead to greatly differing standards for one and the same impact on the environment and to greatly differing results in terms of environmental quality:

Best available technology

This approach involves basing standards on the state-of-the-art. It demands the maximum degree of environmental protection possible on the basis of the current state-of-the-art. It may be stipulated, for example, that improvement of water quality must be directly in line with technical innovation. Aspects such as the relative toxicity of substances, the varying distribution pathways taken by substances and the capacity of the receiving water are not taken into account.

Standards laid down in this way apply in the USA, for example, to industrial dischargers:1)

- Plants built after 1977: "Best practicable control technology currently available"
- Plants built after 1983: "Best available technology economically achievable"
- New sources: "Best available demonstrated technology".

1)Greenwood, D.R. et al. (1983): A Handbook of Key Federal Regulations and Criteria for Multimedia Environmental Control. Research Triangle Kust., Research Triangle Park, W.C.

Uniform emission standards

Such standards limit the concentration of substances, for example in waste water, irrespective of the discharger's location.

Standards of this type are generally based on the "pollution potential" of the dischargers and/or the effectiveness of the recognised or commonly used technologies. Their advantages are that they are easy to monitor and administer and monitoring of pollution is relatively inexpensive.

The disadvantages are that the pollutant load and site of the discharge, along with the capacity and pre-existing pollution level of the surface water, are not taken into account.

Uniform standards can lead to some receiving waters becoming totally overloaded, while the natural self-purification capacity of others is at the same time not fully utilised.

Such standards exist in the form of statutory requirements or guidelines, e.g. in Singapore (Trade Effluent Regulations, 1976; Water Pollution Control and Drainage Act, 1975).

Local emission standards

This method involves laying down standards on the basis of local conditions (which does not necessarily mean environmental conditions) to achieve goals such as a specific water quality.

Advantages: Standards of this type can be updated on the basis of the latest findings and technologies; dischargers are called upon to fulfil more stringent requirements than those actually demanded by the quality goal.

Geoecological conditions and the requirements which the environment is called upon to fulfil are taken into greater account than is the case with any other method. This method is therefore often considered better than the two referred to above.

Disadvantages: Administration and monitoring are more difficult because standards may vary from plant to plant. Serious distortions of competition may occur. Standards of this type are applied in countries such as the United Kingdom.

However, differences in the values stipulated by standards cannot be ascribed solely to the use of different strategies. A role is also played by the different techniques used for performing measurements and transmitting the measured values, the statistical characteristics of the limit value (mean values, peak values, percentiles), the measurement location, etc.

One thing common to all types of standard is that compliance with them must be monitored. A standard is not meaningful unless it can be established whether the actual level is above or below the standard and how far it deviates from the standard. However, the nature of the monitoring system plays a crucial role in determining the results obtained; different monitoring systems may arrive at totally different results for one and the same actual situation.

It follows that there are very close links between a standard and the monitoring system. Indeed, determination of a standard must incorporate stipulation of the basic monitoring principles.

Yet even if two different countries apply identical, equally well-defined standards for a particular substance, it must not be concluded that equal importance is attached to these standards, for example within the framework of the air pollution control strategy of the two countries concerned. It is thus also essential to ask, for instance, what happens when the standard is exceeded; in other words, to ascertain the philosophy behind the standards and the entire concept of air pollution control. If - to take an extreme case - nothing happens in one country, whereas in the other a plant is closed down, it is clear that the importance attached to the standards from the monitoring viewpoint is totally different even though they lay down identical values. Unless all the aspects involved in defining standards are known and taken into account, it thus cannot be concluded that a country with a low SO2 standard pursues a tougher policy on air pollution control than a country in which a higher limit applies.

In the light of these considerations, the following points should be borne in mind when interpreting and using standards:

1. The range of existing standards is immense. It is thus neither feasible nor expedient to make a collection of all available standards. Such a collection would be the size of a small library and would not make any major contribution to achieving the goal set. Any compilation of standards that is possible and meaningful within a given context can therefore represent only a more or less arbitrary selection from such a collection.

2. A standard does not consist simply of a single figure; definition of standards calls for a wealth of information. Comparison of standards from different countries is a complex process which must be carried out with great care and requires a high degree of expertise. The standards collected thus cannot be analysed and interpreted on the basis of strictly scientific criteria, but must essentially be subjected to an interpretative appraisal, especially as the reasons for particular standards can be ascertained from the normally available documentation only through "detective work" or not at all.

This applies in particular to

- establishment of the reasons for particular standards and the related assessment of their validity (i.e. the appropriateness of their content) and their applicability to other countries;

- statistical analysis of what is often a wide range of different standards for a particular pollutant;

- recommendation of individual standards for use.

For the reasons mentioned above, it is probably virtually impossible to classify standards according to their "soundness" (i.e. their "quality" and thus their correctness/appropriateness/ reliability).

3. The collected standards and analysis of them give no indication of whether and to what extent regional geoecological conditions played a part in their formulation. On the contrary, it must be pointed out that countries with a more sensitive environment often apply higher (i.e. more generous) standards than those with a less sensitive environment. There are certain indications that the condition of the environment is more likely to play a role: a poor environmental situation may well result in generous standards being laid down, as enforcement of more stringent ones would involve unacceptable expense or would not be possible at all. Countries which have no chemical industry or lack functioning monitoring systems will have tougher standards for the same emissions, as compliance with them is ensured without the need for elaborate systems or is not monitored.

4. For fundamental scientific reasons, standards must never be regarded as limits below which there will be no negative impacts but above which the consequences will be disastrous. Every standard is at best merely one aspect (often chosen arbitrarily and dependent on many criteria that cannot be objectivised and are often unrelated to the area concerned) in the (generally unknown) functional relationship between impact or condition and the damage caused. The use of standards as "yes/no" decision-making criteria in the administrative and legal fields (e.g. in connection with granting of trade permits or legal actions to recover damages) does not indicate, let alone substantiate, their "correctness" or justifiability on the basis of scientific criteria. Standards which are not directly receptor-oriented, particularly emission standards, cannot do more than serve as guidelines for eliminating what are clearly insignificant aspects from further study. (However, standards which relate to concentrations and not to pollutant loads are totally unsuitable for this purpose as well).

Inappropriate decisions may be reached if standards are used without explicit consideration of all the marginal conditions limiting their validity.

The frequent need to weigh competing environmental goals against each other (e.g. emission or waste water pollution?) or to weigh the claims of environmental goals against those of economic goals calls for more varied criteria and yardsticks than standards can offer.

5. Quantitative standards (lending themselves in principle to measurement and objective monitoring) have been used hitherto for the most part to determine the presence of substances and pollutants in environmental media. They do not cover the particularly serious consequences of action taken by man to shape the environment and the effects which this may have on usable resources (and thus on the basis of economic activity) and on fauna and flora.

Given the present situation as regards scientific discussion and development of standards, it must be said that standards are at best an aid that should be used with the utmost caution in environmental studies. Under no circumstances should the decision on whether or not a project is to be implemented be made solely contingent upon compliance or non-compliance with standards.

At the same time, however, there can be no doubt that standards are an essential aid to evaluating the environmental impacts of project measures.

1.3 Structure of the compendium of environmental standards (CES)

The Compendium of Environmental Standards is based on two classification principles:

1. On the basis of the direct starting points for standards, a distinction is made between two categories:

Standards pertaining to the release/discharge of pollutants/ noise/heat and the use of environmental media (influences on the environment) (Section 3)

Standards pertaining to environmental quality (Section 4)

Further distinctions are accordingly made on the basis of impact or source categories and aspects of environmental quality (elements to be protected, sectors of the environment, media etc.) (see matrices overleaf).

Matrix: Standards for influences on the environment

Impacts on the environment:

1 Waste water
2 Waste heat
3 Emission
4 Solid wastes
5 Chemical aids
6 Changes in land-use
7 Removal of soil
8 Action influencing the water balance
9 Action influencing the surface configuration
10 Noise emission


Sources, measures
Focal areas of project activities

1 2 3 4 5 6 7 8 9 10
  - Standards/Related impacts -
Transport (road, rail, water, air)  
Municipal water supply  
Municipal waste disposal (Impacts of varying intensity)
Manufacturing industry  
Mining, raw-material recovery  
Hydraulic engineering measures (irrigation and drainage, etc.)  
Other (e.g. fisheries, housing, telecommunications)  

Matrix: Standards for environmental quality

Goals, receptors, elements to be protected

1 Man
2 Natural household
3 Fauna and flora
4 Cultural and material assets

Requirements in respect of environmental quality from the receptors' viewpoint relate to

1 2 3 4

Effects Requirements

- Standards/Related impacts -

Air quality  
Climatic situation  
Noise situation  
Available water supply

(Impacts of varying intensity/requirements of varying types and stringency)

Water quality  
Soil quality  
Agricultural/forestry land  
Special biotope functions  
Food quality  
Special uses and functions  

2. On the basis of the areas covered by existing data sources and specialist fields, it is possible to define "information categories" which can be viewed as relatively independent volumes of information. They essentially comprise the following:

Sources, measures and project activities
(Equipment, plants, planning and construction measures, source-specific standards)

Chemical substances
(Individual substances, compounds and substance groups that can be clearly defined in chemical terms)

Non-specific substance categories
(Substance groups that are non-specific in chemical/physical terms, collective designations used in environmental planning for particular substance groups)

Parameters and indicators
(Physical or ecological measured values, parameters and indicators, with the exception of substances and substance categories)

Environmental media
(Individual parameters, standards or indicators for determining the quality of environmental media)

Acceptors and elements to be protected
(Individual parameters, standards or indicators for determining environmental quality with respect to specific acceptors or elements to be protected, excluding environmental media)

Categories or environmental subsectors used in specialised planning
(Environmental subsectors used in specialised planning)

Uses and functions
(Individual parameters, standards or indicators for determining the environmental quality of specific areas of land, forms of land-use and land functions)

International environment legislation
(EC treaties and international multilateral environment treaties)

Regulations and guidelines
(National and international regulations and guidelines, methods for controlling factors influencing the environment and for determining environmental quality)

The information categories "Chemical Substances and Groups of Substances" and "International Environment Legislation" are covered by separate sections in the CES. The information in question is compiled as registers in the form of tables, overviews and information sheets. Both classification principles reflect the potential main areas of interest, while at the same time defining the framework for further processing and for updating.

A certain degree of redundancy has been allowed for in order to enhance readability and on pragmatic grounds. For example, the text concerning "standards in the EC Water Protection Directive" is included in the section "International Environment Legislation", while the water-related standards in respect of chemical substances are in turn given with the other information on the substances in question in the section "Chemical Substances". Each of the sections is thus self-contained. Each can be seen as a source of data for the other, with a certain amount of overlap in terms of content.

Another important aspect of the overall CES concept is that the work is intended to be viewed as a manual which both provides information and draws attention to other information sources. Examples of the latter include compendiums on hazardous goods (e.g. HOMMEL, most recent version), lists of protected species (e.g. IUCN database), compilations of chemical data (e.g. IRPTC, 1987; UN-CLP, most recent version) and compilations of legal texts (e.g. BURHENNE, most recent version). Some registers have in part been incorporated directly in the CES. Where appropriate, additional data could be included or sections combined and new registers defined.

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