Environmental Engineering Reference
In-Depth Information
directive sets out a precise timetable for action, with 2015 as the target date. That means
that not only low levels of chemical pollution but also sustaining healthy aquatic ecosys-
tems have to be achieved. In this sense, the WFD is complemented by other legislations
regulating specific aspects of water.
Particularly in terms of chemical pollution, there are differences between surface water
and groundwater. Regarding surface water, to define good chemical status, environmen-
tal quality standards have to be established for chemical pollutants of high concern across
the EU, that is, the concentration of these compounds should not exceed in order to pro-
tect human health and the environment. The rules for groundwater are slightly differ-
ent; groundwater should not be polluted at all and any pollution must be detected and
stopped.
Groundwater is the main source of public drinking water. The EU Groundwater Directive
(GWD) 2006/118/EC (European Commission 2006) on the protection of groundwater against
chemical pollution and deterioration was developed under Article 17 of the WFD and sets
out criteria for the assessment of the chemical status of groundwater. The GWD estab-
lishes groundwater quality standards for pesticides. For individual pesticides, including
active substances and their relevant metabolites and degradation and reaction products,
the quality standard is 0.1 μg/L and for the total pesticides, it is 0.5 μg/L. Furthermore,
the directive specifies that “total” means the sum of all individual pesticides detected and
quantified in the monitoring procedure, including their relevant metabolites, degradation,
and reaction products. They are the same criteria of the previous Drinking Water Directive
(DWD) (European Commission 1998), where not only the active ingredient but also its
relevant metabolites and degradation products had already been considered “pesticide.”
These general quality standard values are not based on any scientific findings but mean
that pesticides should not be present in water or be below the detection limit. It is not pos-
sible to determine how many pesticides have to be considered in total as this will vary
among catchment areas and could add up to hundreds of pesticides.
But there is an additional input in the GWD; if the groundwater quality standards for
pesticides are not sufficient to meet the objectives of the WFD, for example, if there is an
identified risk for associated terrestrial ecosystems or for other legitimate uses or func-
tions of groundwater, Member States need to establish more stringent values, known as
threshold values. Two criteria can be considered when deriving threshold values: environ-
mental criteria when the protection of associated aquatic ecosystems and groundwater-
dependent terrestrial ecosystems is the concern; and usage criteria, where the threshold
values aim at the protection of drinking water in Drinking Water Protected Areas. The list
of threshold values established by Member States should be regularly reviewed within the
river basin management planning framework. As a consequence, additional substances
can be considered in case of new identified risks, or some substances can be deleted in case
formerly identified risks no longer exist.
The GWD also states that there should be consistency with other EU legislation and,
in particular, for pesticides, consistency with Council Directive 91/414/EEC (European
Commission 1991) concerning the placing of plant protection products on the market has
to be guaranteed. This directive was substituted by the regulation 1107/2009 (European
Commission 1991) in June 2011 by which the directive was revised and improved.
The strategy against pollution of surface waters is set out in Article 16 of the WFD
(European Commission 2000), which requires the establishment of a list of priority sub-
stances and a procedure for the identification of priority substances/priority hazardous
substances as well as the adoption of specific measures against pollution with these
substances. The objective is to protect the aquatic environment from effects such as acute
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