Aquifer — a subsurface layer or layers of rock or other geological strata of sufficient porosity and permeability to allow either a significant flow of groundwater or the abstraction of significant quantities of groundwater 11.

Artificial water body — a body of surface water created by human activity 8.

Available groundwater resource — the long-term annual average rate of overall recharge of the body of groundwater less the long-term annual rate of flow required to achieve the ecological quality objectives for associated surface waters specified under Article 4, to avoid any significant diminution in the ecological status of such waters and to avoid any significant damage to associated terrestrial ecosystems 27.

Body of groundwater — a distinct volume of groundwater within an aquifer or aquifers 12.

Body of surface water — a discrete and significant element of surface water such as a lake, a reservoir, a stream, river or canal, part of a stream, river or canal, a transitional water or a stretch of coastal water 10.

Coastal water — surface water on the landward side of a line, every point of which is at a distance of one nautical mile on the seaward side from the nearest point of the baseline from which the breadth of territorial waters is measured, extending where appropriate up to the outer limit of transitional waters 7.

Combined approach — the control of discharges and emissions into surface waters according to the approach set out in Article 10 36.

Competent Authority — an authority or authorities identified under Article 3(2) or 3(3) 16.

Deterioration of the status of a body of water — the lowering of the status of at least one of the quality elements, within the meaning of Annex V, by one class, even if that lowering does not result in a fall in the classification of the body of water as a whole; however, if a quality element is already at the lowest class, any further deterioration of that element constitutes a deterioration of the status of the body of water 42.

Direct discharge to groundwater — discharge of pollutants into groundwater without percolation throughout the soil or subsoil 32.

Ecological status — an expression of the quality of the structure and functioning of aquatic ecosystems associated with surface waters, classified in accordance with Annex V 21.

Effect-based trigger value — a threshold for the effects of a pollutant or group of pollutants in water, sediment or biota, where those effects are measured by an appropriate and scientifically validated effect-based monitoring method, above which adverse effects on human health or the environment from that pollutant or group of pollutants in water, sediment or biota, could occur 35a.

Emission controls — controls requiring a specific emission limitation, for instance an emission limit value, or otherwise specifying limits or conditions on the effects, nature or other characteristics of an emission or operating conditions which affect emissions. Use of the term ‘emission control’ in this Directive in respect of the provisions of any other Directive shall not be held as reinterpreting those provisions in any respect 41.

Emission limit values — the mass, expressed in terms of certain specific parameters, concentration and/or level of an emission, which may not be exceeded during any one or more periods of time. Emission limit values may also be laid down for certain groups, families or categories of substances, in particular for those identified under Article 16. The emission limit values for substances shall normally apply at the point where the emissions leave the installation, dilution being disregarded when determining them. With regard to indirect releases into water, the effect of a waste-water treatment plant may be taken into account when determining the emission limit values of the installations involved, provided that an equivalent level is guaranteed for protection of the environment as a whole and provided that this does not lead to higher levels of pollution in the environment 40.

Environmental objectives — the objectives set out in Article 4 34.

Environmental quality standard — the concentration of a particular pollutant or group of pollutants in water, sediment or biota not to be exceeded in order to protect human health and the environment 35.

Good ecological potential — the status of a heavily modified or an artificial body of water, so classified in accordance with the relevant provisions of Annex V 23.

Good ecological status — the status of a body of surface water, so classified in accordance with Annex V 22.

Good groundwater chemical status — the chemical status of a body of groundwater, which meets all the conditions set out in table 2.3.2 of Annex V 25.

Good groundwater status — the status achieved by a groundwater body when both its quantitative status and its chemical status are at least ‘good’ 20.

Good quantitative status — the status defined in table 2.1.2 of Annex V 28.

Good surface water chemical status — the chemical status required to meet the environmental objectives for surface waters set out in Article 4(1)(a) of this Directive, that is the chemical status achieved by a body of surface water in which concentrations of pollutants exceed neither the environmental quality standards for priority substances listed in Part A of Annex I to Directive 2008/105/EC of the European Parliament and of the Council ( 1 ) nor the environmental quality standards for river basin specific pollutants set and applied in accordance with Article 8d of that Directive, and in which effect-based trigger values, where available, are also not exceeded 24.

Good surface water status — the status achieved by a surface water body when both its ecological status and its chemical status are at least ‘good’ 18.

Groundwater — all water which is below the surface of the ground in the saturation zone and in direct contact with the ground or subsoil 2.

Groundwater status — the general expression of the status of a body of groundwater, determined by the poorer of its quantitative status and its chemical status 19.

Hazardous substances — substances or groups of substances that are toxic, persistent and liable to bio-accumulate, and other substances or groups of substances which give rise to an equivalent level of concern 29.

Heavily modified water body — a body of surface water which as a result of physical alterations by human activity is substantially changed in character, as designated by the Member State in accordance with the provisions of Annex II 9.

Inland water — all standing or flowing water on the surface of the land, and all groundwater on the landward side of the baseline from which the breadth of territorial waters is measured 3.

Lake — a body of standing inland surface water 5.

Pollutant — any substance liable to cause pollution, in particular those listed in Annex VIII 31.

Pollution — the direct or indirect introduction, as a result of human activity, of substances or heat into the air, water or land which may be harmful to human health or the quality of aquatic ecosystems or terrestrial ecosystems directly depending on aquatic ecosystems, which result in damage to material property, or which impair or interfere with amenities and other legitimate uses of the environment 33.

Priority hazardous substances — priority substances which are identified as “hazardous” in accordance with the legislation referred to in Article 16(3) 30a.

Priority substances — substances listed in Part A of Annex I to Directive 2008/105/EC, that are substances which present a significant risk to or via the aquatic environment and are prioritised in accordance with Article 16(2) of this Directive 30.

Quantitative status — an expression of the degree to which a body of groundwater is affected by direct and indirect abstractions 26.

River — a body of inland water flowing for the most part on the surface of the land but which may flow underground for part of its course 4.

River basin — the area of land from which all surface run-off flows through a sequence of streams, rivers and, possibly, lakes into the sea at a single river mouth, estuary or delta 13.

River basin district — the area of land and sea, made up of one or more neighbouring river basins together with their associated groundwaters and coastal waters, which is identified under Article 3(1) as the main unit for management of river basins 15.

River basin specific pollutants — pollutants that are not or no longer identified as priority substances, but which Member States have identified, on the basis of the assessment of pressures and impacts on surface water bodies carried out in accordance with Annex II, as being discharged or deposited in significant quantities into a river basin or sub-basin and thus posing a significant risk to or via the aquatic environment within their territory 30b.

Sub-basin — the area of land from which all surface run-off flows through a series of streams, rivers and, possibly, lakes to a particular point in a water course (normally a lake or a river confluence) 14.

Surface water — inland waters, except groundwater; transitional waters and coastal waters, except in respect of chemical status for which it shall also include territorial waters 1.

Surface water status — the general expression of the status of a body of surface water, determined by the poorer of its ecological status and its chemical status 17.

Transitional waters — bodies of surface water in the vicinity of river mouths which are partly saline in character as a result of their proximity to coastal waters but which are substantially influenced by freshwater flows 6.

Water intended for human consumption — borrowed from another act; this instrument states no meaning of its own 37.

Water services — all services which provide, for households, public institutions or any economic activity: (a) abstraction, impoundment, storage, treatment and distribution of surface water or groundwater, (b) waste-water collection and treatment facilities which subsequently discharge into surface water 38.

Water use — water services together with any other activity identified under Article 5 and Annex II having a significant impact on the status of water. This concept applies for the purposes of Article 1 and of the economic analysis carried out according to Article 5 and Annex III, point (b) 39.