Lakes and Watercourses

included. In addition to a large number of chemical parameters, there are
several that provide direct or indirect measures of biodiversity.
In all of the reports, assessments of environmental quality are handled
in the same way for all of the parameters, and usually consist of two separate
parts (see also page 11). One part focuses on the effects that observed
conditions can be expected to have on environment and human health.
Since knowledge of such effects is often limited, the solution in many cases
has been to present a preliminary classification scale based on general
knowledge about the high and low values that are known to occur in Sweden.
The second focuses on the extent to which measured values deviate
from established reference values. In most cases, the reference value represents
an approximation of a “natural” state, i.e. one that has been affected
very little or not at all by human activities. Of course, “natural” is a concept
that is not relevant to the preservation of cultural environments; in such
contexts, reference values have a somewhat different meaning.
The results of both parts are expressed on a scale of 1-5, where Class 1
indicates slight deviations from reference values or no environmental
effects, and Class 5 indicates very large deviations or very significant effects.
The report on Contaminated Sites with its discussion of pollutants in
heavily affected areas complements the other five reports. In those cases
where the parameters are dealt with in several of the reports, which is particularly
the cases for metals, the report on Contaminated Sites corresponds
(see further pages 11-12). However, the various parameters cannot
be compared with each other in terms of risks. The following paragraphs
review the extent of agreement with corresponding or similar systems used
by other countries and international organizations.
INTERNATIONAL SYSTEMS FOR ENVIRONMENTAL QUALITY ASSESSMENT
Among other countries, the assessment system that most resembles Sweden's
is that of Norway. The Norwegian system includes “Classification of
Environmental Quality in Fjords and Coastal Waters” and “Environmental
Quality Classification of Fresh Water”. A five-level scale is used to classify
current conditions and usability. Classifications are in some cases based on
levels of pollution, in other cases on environmental effects.
The European Union's proposal for a framework directive on water quality
includes an assessment system that in many ways is similar to the Swedish
Environmental Quality Criteria.
If the parameters used in the latter are regarded as forms of environmental
indicators, there are many such systems in use or under development. However,
the concept of environmental indicators is much broader than the
parameters of Environmental Quality Criteria.
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