- At the time of submitting this report,
information on monitoring requirements had not been validated the Walloon and Brussels
regions of Belgium.
- Within the EEA area, many requirements for monitoring
arise from the European Commission. However, there are also many other international
commitments which make monitoring requirements.
- Four types of Directive have been employed by the EU
to control the pollution of water: use-related directives; industry sector directives;
substance directives; and, product directives. With the exception of the products
directives, most of these directives require the implementation of monitoring, either
routine programmes or preliminary investigations. The extent to which monitoring
requirements associated with directives overlap depends on commonalities between the
national implementation of directive requirements, and the monitoring undertaken for this
purpose will therefore vary from country to country.
- The requirements made in directives have been
designed largely independently from each other. The Commission has, however, taken some
initiatives to harmonise monitoring requirements and reporting of results in the Exchange
of Information Decision (77/795/EEC as amended by Directive 86/574/EEC) and in the
reporting of implementation of certain directives as specified in the Reporting Decision
- In total four directives and one proposed directive
make requirements for groundwater monitoring (the requirements made in the Dangerous
Substances Directive have been superseded by the Groundwater Directive). The only
international commitment for groundwater monitoring is the 1992 Convention on
Transboundary Water Courses. At present there is no overlap in international monitoring
requirements for groundwater.
- In EU legislation, all monitoring requirements which
apply to rivers, also apply to lakes and reservoirs. Most directives which apply to
freshwaters also apply to salt waters. The Shellfish Waters Directive is the only
directive which applies to estuaries and coastal waters but not freshwaters.
- Of the 15 directives that require monitoring of fresh
surface waters, all include water column monitoring. The Dangerous Substances Directives
and the Titanium Dioxide Directive also require monitoring of sediment and biota. The
Exchange of Information Decisions make the only requirements for flow measurements. There
are eight international agreements which also require monitoring of water quantity in
terms of flow and water level.
- Barriers to the harmonisation of monitoring can be
introduced at the sampling, analysis, and reporting stages, and can arise either because
requirements differ (i.e. conflict) or because requirements are not clearly specified
(i.e. are weak).
- The most specific requirements in terms of named
water bodies and measuring stations are in the Exchange of Information Decision. These
rivers are nationally significant rivers and lakes and as such are quite likely to be
sampled for other national and international obligations (e.g. Rhine and Elbe
- The scope for overlap of sampling locations between
directives appears to be limited to areas where use and designation overlap, which is
probably a limited circumstance in many States. Many of the directives allow the competent
authority of each Member State to make decisions on such aspects as the exact sampling
point, the distance from this point to the nearest point where pollutants are discharged
and the depth at which the samples are to be taken but the same sites and depths should be
used in all surveys, in relation to physical and temporal conditions.
- For international agreements sample location will
generally be related to the purpose of the agreement often being at designated or fixed
sites. Other agreements are less specific about sampling location perhaps being determined
by the needs of signatories or monitoring programme.
- For some directives, once the fate and behaviour of
an effluent is known and the effects have been established, and as long as there is no
deterioration, then there is also scope for the Member States to use a lower sampling
frequency than specified in the directive. Sampling period is not usually specified or, if
it is, the interpretation of its definition can give rise to differences between countries
(for example, bathing season). These imprecise requirements can give rise to different
- The sampling frequency specified in international
agreements is very variable within agreements and between agreements.
- As the choice of sampling location is, for some
directives, related to areas designated by the Member States rather than by the European
Commission, it is unlikely that, for those directives, a comparison of quality across
Europe of these designated waters will give a complete picture of quality because the
degree of comparability will depend on the interpretation of the designation rules and
national differences of how these are implemented. Therefore, the degree of coverage that
water quality data encompasses within each country will be determined by national
designations and the prevalence of the industries that are required to be regulated.
- It is not apparent from most of the published
directives whether there have been any, or if so, what, statistical considerations when
defining the required sampling frequencies or numbers. These aspects have a significant
effect on the statistical precision and confidence of the monitoring data produced. The
required frequency should be derived with reference to the quantified risks that some
waters will be misclassified (against compliance criteria). Furthermore, for fairness of
comparison, the frequency of sampling should be uniform throughout Europe.
- Sources of error in the overall assessment of a
determinand in a water body may include sampling error and analytical error. The
analytical requirements made in the directives are generally very basic and defined in
terms of performance criteria (i.e. limits of detection, precision and accuracy) and/or by
analytical method. The degree of definition, however, varies greatly from directive
to directive. Many directives make very broad requirements to use appropriate
methods for pre-treatment and analysis. The analytical requirements made in
international agreements are also generally very basic and hardly ever defined in terms of
- The performance criteria are the key requirements
with regard to analysis. Despite this several directives, the Titanium Dioxide Directive
and all the use-related directives (except the Surface Water through the Sampling Analysis
Directive) fail to establish performance requirements for analysis. The laboratories
concerned with applying the directives should be free to use appropriate
methods providing they satisfy performance criteria.
- Probably the most significant omission in
requirements for analytical technologies is a requirement for analytical quality control
(AQC). Increasingly AQC is being recognised as essential for data from monitoring
programmes to be reliable and comparable.
- Microbiological methods should be standardised for
efficiency of recovery and performance (accuracy, specificity, precision) and, in order to
secure harmonisation of results between Member States, single reference procedures must be
agreed for each determinand.
- The reporting frequency is variable per directive, as
well as the reporting period covered.
- Another important aspect of directives, particularly
when a comparison of quality across Member States is expressed as a comparison of
compliance against limits and standard values (e.g. as in the Bathing Waters Directive),
is how the compliance requirements in the directives are expressed, calculated and
interpreted. Differences in interpretation of these requirements is another significant
barrier to harmonisation of monitoring and implementation of directives across Europe.
- In addition to the aspects described above, another
significant barrier to obtaining valid and quantitative, temporal and spatial comparisons
of water quality across Europe is the different ways in which directives are implemented
and interpreted at the Member State level. A particular issue of primary importance to the
process of harmonisation is the need to standardise definitions for determinands and
sampling methodologies. This issue has not been addressed in this project, but it is
recommended that such an assessment is undertaken.
- The outputs from Project MW1 and MW2 (inventories of
current monitoring networks) will be used in the next phase of the Topic Centres
work programme for this year - the design of an inland water monitoring network to meet
the needs of the European Environment Agency.