Groundwater bodies

Warning

Last updated - 2026-07-02

Changes based on feedback from WG DIS and WG Groundwater members.

• The “lithology placeholder” was removed.

• The gwAtRiskQuantitative and gwReasonsForRiskQuantitative attributes were reintroduced.

• The gwPollutantCausingRisk and gwPollutantBackgroundLevelSet attributes were reintroduced.

• Further information about the 3rd cycle reporting of natural background levels was included GroundWaterBody - 3rd cycle - Parameters with reported Natural Background Level.

Purpose and overview

This section revises the reporting of information related to Groundwater Bodies in the 2nd and 3rd cycle of reporting of the Water Framework Directive River Basin Management Plans. It also presents a proposal for simplifying the electronic reporting in the 4th cycle.

Current structure - 3rd cycle

In the 3rd cycle, the information about Groundwater bodies was reported in 4 separate schemas:

• the GWB_2022 schema, containing information about each groundwater body (Figure 48)

• the GWMET_2022 schema, containing information about the methodologies (see Groundwater methodologies)

• the GML_GroundWaterBody_2022 schema, containing the GroundWaterBody spatial dataset.

• the GML_GroundWaterBodyHorizon_2022 schema, containing the ancillary GroundWaterBodyHorizon spatial dataset.

GWB_2022 schema - 3rd cycle

The GWB_2022 schema was already partially revised with regard to the reporting of exemptions. See:

• Groundwater chemical exemptions by pollutant

• Groundwater quantitative exemptions

• Groundwater related protected area exemptions

Other simplifications already discussed also apply to the GWB schema:

• removal of the textual reporting of “other” pollutants

• removal of the textual reporting of “other” pressures

• removal of the textual reporting of “other” impacts

The Commission has revised the GroundWaterBody class, and removed the following elements:

• GWB/GroundWaterBody/gwEORiskQuantitative

• GWB/GroundWaterBody/gwEORiskChemical

• GWB/GroundWaterBody/gwAtRiskQuantitative

• GWB/GroundWaterBody/gwAtRiskChemical

• GWB/GroundWaterBody/gwReasonsForRiskQuantitative

The Commission has revised the GWPollutant class, and removed the following elements:

• GWB/GroundWaterBody/GWPollutant/gwPollutantExceedancesNotCounted

        ---
config:
  class:
    hideEmptyMembersBox: true
  layout: dagre
  theme: default
---

classDiagram
class GWChemicalExemptionType ["«XSDcomplexType»
GWChemicalExemptionType"] {
  «XSDelement»
  + gwChemicalExemptionType: GWChemicalExemptionType_Union_Enum
  + gwChemicalExemptionPressure: SignificantPressureType_Enum
}

class GWPollutant ["«XSDcomplexType»
GWPollutant"]{
  «XSDelement»
  + gwPollutantCode: ChemicalSubstances_Enum
  + gwPollutantOther: OtherType [0..1]
  + gwPollutantCausingRisk: YesNoUnknown_Linear_Union_Enum
  + gwPollutantCausingFailure: YesNoCode_Enum
  + gwPollutantUpwardTrend: YesNoUnknownUnknown_Linear_Union_Enum
  + gwPollutantTrendReversal: YesNoUnknownNotApplicable_Code_Enum
  + gwPollutantExceedancesNotCounted: YesNoUnknownCode_Enum
  + gwPollutantBackgroundLevelSet: YesNoCode_Enum
  + gwPollutantBackgroundLevelValue: ThresholdType [0..1]
  + gwPollutantBackgroundLevelUnit: UnitOfMeasure_Enum [0..1]
  + gwPollutantTrendReversalProcess: YesNoUnknownNotApplicableCode_Enum
}

class GWAssociatedProtectedArea ["«XSDcomplexType»
GWAssociatedProtectedArea"]{
  «XSDelement»
  + euProtectedAreaCode: FeatureUniqueEUCodeType
  + protectedAreaType: ProtectedGWAreaType_Enum
  + protectedAreaObjectivesSet: ProtectedAreaObjectivesEnum [0..1]
  + protectedAreaObjectivesMet: YesNoInformation_Union_Enum [0..1]
  + protectedAreaComment: String1000Type [0..1]
  + protectedAreaExemption: ExemptionType_Enum [1..*]
}

class GroundWaterBody ["«XSDcomplexType»
GroundWaterBody"] {
  «XSDelement»
  + euGroundWaterBodyCode: FeatureUniqueEUCodeType
  + linkSurfaceWaterBody: YesNoCode_Enum
  + linkSurfaceWaterBodyCode: FeatureUniqueEUCodeType [0..*]
  + linkTerrestrialEcosystem: YesNoUnknownCode_Enum
  + geologicalFormation: GeologicalFormation_Enum
  + groundwaterBodyTransboundary: YesNoCode_Enum
  + gwSignificantPressureType: SignificantPressureType_Enum [1..*]
  + gwSignificantPressureOther: String100Type [0..1]
  + gwSignificantImpactType: SignificantImpactType_Enum [1..*]
  + gwSignificantImpactOther: String1000Type [0..1]
  + gwAtRiskQuantitative: YesNoCode_Enum
  + gwReasonsForRiskQuantitative: QuantitativeFailure_Enum [0..*]
  + gwEoRiskQuantitative: GWERiskQuantitative_Enum [0..1]
  + gwQuantitativeStatusValue: StatusCode_Enum
  + gwQuantitativeReasonsForFailure: QuantitativeFailure_Enum [0..*]
  + gwQuantitativeAssessmentYear: YearRangeType
  + gwQuantitativeAssessmentConfidence: Confidence_Enum
  + gwQuantitativeStatusExpectedAchievementDate: GoodStatus_Enum
  + gwQuantitativeExemptionType: ExemptionType_Enum [1..*]
  + gwQuantitativeExemptionPressure: SignificantPressureType_Enum [0..*]
  + gwAtRiskChemical: YesNoCode_Enum
  + gwEoRiskChemical: EORiskChemical_Enum [0..1]
  + gwChemicalStatusValue: StatusCode_Enum
  + gwChemicalReasonsForFailure: ReasonsForFailure_Enum [0..*]
  + gwChemicalAssessmentYear: YearRangeType
  + gwChemicalAssessmentConfidence: Confidence_Enum
  + gwChemicalStatusExpectedAchievementDate: GoodStatus_Enum
}

class GWB ["«XSDcomplexType»
GWB"]{
  «XSDelement»
  + countryCode: CountryCode_Enum
  + euRBDCode: FeatureUniqueEUCodeType
}


GWAssociatedProtectedArea --> GroundWaterBody: GWAssociatedProtectedArea
GWPollutant --> GroundWaterBody: GWPollutant
GWChemicalExemptionType --> GWPollutant: GWChemicalExemptionType
GroundWaterBody --> GWB: GroundWaterBody

    

Figure 48 Class diagram for the GWB_2022 schema in the 3rd cycle.

In the 4th cycle of reporting, the data will be delivered in the Reportnet3 platform:

• the remaining GWMET_2022 classes and elements were reorganised into a relational model, as required by the migration to Reportnet3

• selective denormalisation was used to keep a low number of tables and facilitate the quality control

• the requirements of Directive 2006/118/EC also need to be taken into account

(36) In order to ensure a level playing field in the Union and allow comparability of water body status between Member States, there is a need to harmonise national threshold values for some man-made synthetic groundwater pollutants. Threshold values should be established as necessary at Union level for pollutants which have an anthropogenic origin or for the products of their degradation or decomposition, provided that those pollutants and degradation products either do not occur naturally in groundwater, or, if identical natural counterparts exist, provided that their natural background levels are, at most, low. Those threshold values should be included in the repository of harmonised threshold values for man-made synthetic substances in groundwater of national, regional or local concern in a new Part D of Annex II to Directive 2006/118/EC. A harmonised threshold value for individual pharmaceuticals should be included for application by Member States to any pharmaceutical active substance identified as posing a risk at national level unless a stricter standard or threshold value has been set specifically for that substance at Union or national level.

(37) All provisions of Directive 2006/118/EC relating to the assessment of groundwater chemical status should be adapted to the introduction of the third category of harmonised threshold values in a new Part D of Annex II to that Directive, in addition to the quality standards set out in Annex I to that Directive and the national threshold values set out in accordance with the methodology set out in Part A of Annex II to that Directive.

—ELI: http://data.europa.eu/eli/dir/2026/805/oj

Groundwater - descriptive data - 4th cycle

The proposed structure for the 4th cycle electronic reporting is presented in the class diagram in Figure 49 and a brief description of each table is included in Table 44.

• The core data about each groundwater body is reported in 3 tables: GroundWaterBody, LinkSurfaceWaterBody and GWNaturalBackgroundLevel.

  • The content of this set of tables does not depend of the status assessment, and can be prepared in advance.

• A second set of tables contains information about the chemical and quantitative status assessment and about pressures and impacts: GroundWaterBodyStatus, GWQuantitativeStatus, GWPollutant and GWPressureImpact.

  • The ancillary table GWGrouping supports the reporting of grouping (if used the assessment).

  • A link to the GWMethodologies::ThresholdValue table clarifies which threshold value is applied to each pollutant.
    (A list of the default EU threshold values will be provided where defined by the EU legislation.)

        ---
config:
  class:
    hideEmptyMembersBox: true
  layout: dagre
  theme: neutral
  themeVariables:
    noteBkgColor: LightYellow
    noteTextColor: black 
---
classDiagram
direction TB

class GWLinkSurfaceWaterBody{
    + euGroundWaterBodyCode: wiseIdentifier
    + euSurfaceWaterBodyCode: wiseIdentifier
    + linkType: GroundwaterSurfaceWaterLink
}

class GWNaturalBackgroundLevel{
    + euGroundWaterBodyCode: wiseIdentifier
    + parameterCode: Parameter
    + naturalBackgroundLevelSet: YesNo
    + parameterValue: range [0..1]
    + parameterUnit: UnitOfMeasure [0..1]
}

class GroundWaterBody{
    + euGroundWaterBodyCode: wiseIdentifier
    + aquiferType: AquiferMediaTypeValue
    + aquiferProductivity: AquiferProductivity
    + groundWaterBodyTransboundary: YesNo
    + linkSurfaceWaterBody: YesNo
    + linkTerrestrialEcosystem: YesNoUnknown
}

class GWQuantitativeStatus{
    + euGroundWaterBodyCode: wiseIdentifier
    + gwQuantitativeStatusValue: QuantitativeStatus
    + gwQuantitativeAssessmentPeriod: range
    + gwQuantitativeAssessmentConfidence: AssessmentConfidence
    + gwQuantitativeAssessmentMethod: AssessmentMethod [1..n]
    + gwGroupingIdentifier: wiseIdentifier [0..n]

    + gwAtRiskQuantitative: YesNo
}

class GWPressureImpact{
    + euGroundWaterBodyCode: wiseIdentifier
    + gwPressureType: PressureType [0..1]
    + gwImpactType: ImpactType  [0..1]
}

class GWStatus{
    
    + euGroundWaterBodyCode: wiseIdentifier
    + gwQuantitativeStatusValue: QuantitativeStatus
    + gwChemicalStatusValue: ChemicalStatus

    + gwQuantitativeReasonsForFailure: ReasonForFailure [1..n]
    + gwQuantitativeReasonsForRisk: ReasonForFailure [1..n]
    + gwChemicalReasonsForFailure: ReasonForFailure [1..n]
} 

class GWPollutant{
    + euGroundWaterBodyCode: wiseIdentifier
    + gwPollutantCode: Parameter

    + gwThresholdIdentifier: wiseIdentifier
    + gwGroupingIdentifier: wiseIdentifier [0..n]
    + gwPollutantCausingFailure: YesNoUnknown
    + gwPollutantAssessmentPeriod: range
    + gwPollutantAssessmentConfidence: AssessmentConfidence 
    + gwPollutantAssessmentMethod: AssessmentMethod [1..n]

    + gwPollutantCausingRisk: YesNoUnknown

    + gwPollutantUpwardTrend: YesNoUnknownNotAssessed
    + gwPollutantTrendReversal: YesNoUnknownNotApplicableNotAssessed
    + gwPollutantTrendReversalProcess: YesNoUnknownNotApplicableNotAssessed

}

class GWGrouping{
    + gwGroupingIdentifier: wiseIdentifier
    + euGroundWaterBodyCode: wiseIdentifier
}

GroundWaterBody "1" -- "1" GWStatus    
GWStatus "1" -- "0..1" GWQuantitativeStatus
GWStatus "1" -- "0..n" GWPollutant
GWStatus "1" -- "0..n" GWPressureImpact

GWQuantitativeStatus ..> GWGrouping: gwGroupingIdentifier
GWPollutant ..> GWGrouping: gwGroupingIdentifier

GWLinkSurfaceWaterBody "0..n" -- GroundWaterBody: {linkSurfaceWaterBody = 'Yes'}
GWNaturalBackgroundLevel "0..n" -- GroundWaterBody

GWNaturalBackgroundLevel .. GWPollutant: {quality control}

%% note for GWPollutant "GroundwaterMethodologies::ThresholdValue.gwThresholdIdentifier"

classDef default fill:white,stroke:#000;
classDef forFixing fill:white,stroke:#f00;

    

Figure 49 Groundwater - descriptive data - 4th cycle

Table 44 Groundwater - 4th cycle - brief table description

Table	Description
GroundWaterBody	modified The GroundWaterBody table contains the attributes that describe the groundwater body and that do not vary with the status of the water body. Therefore the table can be prepared immediately, even if the 4th cycle RBMPs have not yet been finalised. All the attributes existed in the 3rd cycle reporting. The linkSurfaceWaterBody value controls the content of the LinkSurfaceWaterBody table. In the 3rd cycle, the reporting guidance requested description of “the main geological formation of the aquifer type”. The usability of the reported data was limited, beyond visualisation purposes. For the 4th cycle, a suggestion is made to split the data in two attributes: aquiferMediaType and aquiferProductivity, using the separation already present in the published WISE_WFD database and in the WISE visualisations. However, expert guidance must be provided, specially with regard to the aquifer productivity classes, their definition and comparability across Member States.
GWLinkSurfaceWaterBody	modified. If the groundwater body is linked to one or more surface water bodies, that relation is reported in the GWLinkSurfaceWaterBody table. The linkType attribute specifies the type of water flow between the groundwater and the surface water body.
GWNaturalBackgroundLevel	modified The data related to the natural background level (NBL) of substances in groundwater is moved from the GWPollutant class into a separate GWNaturalBackgroundLevel table. This facilitates both the reporting and the quality control procedures that will be introduced to avoid mistakes in the reporting (see Natural background levels).
GWStatus	new The GWStatus table synthesizes information about the status of the water body, and the causes of failure (if applicable). Formally, the chemicalStatusValue could be derived from the information in the GWPollutant table. If, and only if, chemicalStatusValue = 'unknown' and no assessment of the chemical status was done, may all corresponding rows in the GWPollutant table be missing. (An ERROR will raised by the quality control, since this is a non-compliance and should not be reported by mistake.) Likewise, the quantitativeStatusValue could be derived from the GWQuantitativeStatus table. If, and only if, quantitativeStatusValue = 'unknown' and no assessment of the quantitative status was done, may the corresponding row in the GWQuantitativeStatus table be missing. (An ERROR will raised by the quality control, since this is a non-compliance and should not be reported by mistake.)
GWPollutant	modified The GWPollutant table contains data related to the chemical status at substance level. The information about the assessment method, assessment confidence, and assessment period can be reported at pollutant level, allowing more flexibility in reporting different situations for different pollutants or indicators of pollution. (If the same method, confidence and period apply to all substances assessed for a groundwater body, then identical values can be reported for all substances) The threshold value used in the assessment is specified in the gwThresholdIdentifierattribute, linking to the GWMethodologies::ThresholdValue table (or to the European standard if applicable).
GWQuantitativeStatus	new The GWQuantitativeStatus table gathers the data related to quantitative status. The assessment method, confidence and period is reported using the same pattern applied for groundwater pollutants. It is now possible to report the use of grouping for the quantitative status assessment.
GWGrouping	new If grouping was not used, this table is not necessary. If grouping was used for the assessment of quantitative or chemical status, the GWGrouping table is used to define sets of water bodies that were monitored and assessed together as an ensemble. The same ensemble can be used for different purposes. The same water body can be a member of different ensembles. The groupingIdentifier value uniquely identifies an ensemble using the WISE identifier syntax. The euGroundWaterBodyCode identifies a member of the ensemble. If an ensemble is used in the assessment of a given element, then at least one of its water bodies must be monitored for that element (i.e. must have gwPollutantAssessmentMethod = 'monitoring'). (To avoid mistakes and ambiguities, the groupingIdentifier value must be different from any known water body identifier. It is recommended to use a clear pattern to avoid conflicts with existing and future water body identifiers. For example, using a ‘_GWGROUPING’ suffix).
GWPressureImpact	modified. For the water bodies that do not achieve good quantitative status in 2027, the significant pressures causing poor quantitative status are reported in the GWQuantitativeExemption table (see Figure 44) and do not need to be reported again in the GWPressureImpact table. For water bodies that do not achieve good chemical status in 2027, the significant pressures are reported in the GWChemicalExemption table (see Figure 43) and do not need to be reported again in the GWPressureImpact table. For cases where a pressure is not causing failure, but still causes an impact that needs to be managed, the GWPressureImpact table should be used. Note that the reporting of pressures and impacts is combined into a single GWPressureImpact table. In the 3rd cycle, the XML structure did not allow a specific pressure to be link to a given impact. In the proposed structure, this is possible (but not mandatory). Illustrative examples will be provided.

Groundwater - codelists - 4th cycle

• For the AquiferMediaTypeValue codelist, see Figure 50.
  The codelist was realigned with the INSPIRE codelist to allow more flexibility.

  • See the definitions in Table 45.

• For the AquiferProductivity codelist, see Figure 50.
  The codelist allows the reporting of aquifer productivity independently of the aquifer media values.
  Further technical guidance on concepts, classification schemes and class boundaries is needed.[1]

  • See the definitions in Table 46.

• For the AssessmentMethod codelist, see Figure 51.
  The codelist is used to report the assessment method for the chemical status and for the quantitative status.
  The same codelist is used for surface water bodies, for the assessment method of ecological status or potential, and for the assessment method of chemical status.

  • See the definitions in Table 47.

• For the AssessmentConfidence codelist, see also Figure 51.
  The codelist allow the reporting of the level of confidence in the results of the status assessment.
  The same codelist is used for surface water bodies. See also [2] [3] [4].

  • See the definitions in Table 48.

• For the GroundwaterSurfaceWaterLink codelist, see Figure 52.
  The codelist is used to report the type of link between a given groundwater body and a given surface water body.

  • See the definitions in Table 49.

• For the ReasonForFailure codelist, see Figure 53.

  • See the definitions in Table 50.

  • For groundwater bodies in poor quantitative status, the codelist values are used in the gwQuantitativeReasonsForFailure attribute to provide further information about one or more causes of failure (the most frequent cause will be likely be 'waterBalance').
    For groundwater bodies in good or unknown quantitative status, the option notApplicable must be used.

  • For groundwater bodies failing to achieve good chemical status, the codelist values are used in the gwChemicalReasonsForFailure attribute to provide further information about one or more causes of failure (the most frequent cause will be likely be 'waterQuality').
    For groundwater bodies in good or unknown quantitative status, the option notApplicable must be used. For groundwater bodies in good or unknown chemical status, the option notApplicable must be used.

  • For groundwater bodies where good quantitative status is at risk, the codelist values are used in the gwQuantitativeReasonsForRisk attribute to provide further information about one or more causes of risk. For groundwater bodies where gwAtRiskQuantitative = 'no' the option notApplicable must be used.

• For the PressureType codelist, see Figure 86 in the section PressureType codelist - 4th cycle

        ---
config:
  class:
    hideEmptyMembersBox: true
  layout: dagre
  theme: neutral
---
classDiagram
direction TB

class AquiferMediaTypeValue{
<<enumeration>>
compound
fractured
karstic
karsticAndFractured
porous
porousAndFractured
other
unknown
}

class AquiferProductivity{
<<enumeration>>
high
moderate
low
insignificant
unknown
}

classDef default fill:white,stroke:#000;
classDef forFixing fill:white,stroke:#f00;

    

Figure 50 AquiferMediaTypeValue codelist and AquiferProductivity codelist - 4th cycle

Table 45 Codelist - 4th cycle - AquiferMediaTypeValue

Notation	Label	Definition	URI
compound	Compound	A combination of a porous, karstic and/or fractured aquifer.	https://inspire.ec.europa.eu/codelist/AquiferMediaTypeValue/compound
fractured	Fractured	Fractured aquifers are rocks in which the primary porosity is negligible and the water circulation is through the secondary porosity (fractures, faults, joints, bedding planes).	https://inspire.ec.europa.eu/codelist/AquiferMediaTypeValue/fractured
karstic	Karstic	Karstic aquifers are fractured aquifers where the cracks and fractures have been enlarged by solution, forming large channels or even caverns.	https://inspire.ec.europa.eu/codelist/AquiferMediaTypeValue/karstic
karsticAndFractured	Karstic and fractured	A combination of karstic and fractured aquifer.	https://inspire.ec.europa.eu/codelist/AquiferMediaTypeValue/karsticAndFractured
porous	Porous	Porous aquifers are unconsolidated or consolidated deposits where water circulates through pores between the grains.	https://inspire.ec.europa.eu/codelist/AquiferMediaTypeValue/porous
porousAndFractured	Porous and fractured	A combination of porous and fractured aquifer.	https://inspire.ec.europa.eu/codelist/AquiferMediaTypeValue/porousAndFractured
other	Other	Other aquifer media types not covered by the other values.	https://inspire.ec.europa.eu/codelist/AquiferMediaTypeValue/other

Table 46 Codelist - 4th cycle - AquiferProductivity

Notation	Label	Definition
high	High productivity	«to-be-provided»
moderate	Moderate productivity	«to-be-provided»
low	Low productivity	«to-be-provided»
insignificant	Insignificant productivity	«to-be-provided»
unknown	Unknown	No information is available about the aquifer’s productivity

        ---
config:
  class:
    hideEmptyMembersBox: true
  layout: dagre
  theme: neutral
---
classDiagram
direction TB

class AssessmentMethod{
<<enumeration>>
  monitoring
  grouping
  remoteSensing
  modelling
  expertJudgement
  notApplicable
}

class AssessmentConfidence{
<<enumeration>>
  high
  medium
  low
  unknown
  notApplicable
}

classDef default fill:white,stroke:#000;
classDef forFixing fill:white,stroke:#f00;

    

Figure 51 AssessmentMethod codelist and AssessmentConfidence codelist - 4th cycle

Table 47 Codelist - 4th cycle - AssessmentMethod

Notation	Label	Definition	Notes
monitoring	Monitoring	The status assessment used monitoring data collected at the water body being assessed.	This includes monitoring through conventional in situ sampling (including grab sampling, continuous sampling, passive sampling, eDNA sampling, etc.).
grouping	Grouping	The status assessment used monitoring data from other similar water body(ies).	Choose only ‘grouping’ if no monitoring data for the water body was used in the assessment, and only monitoring data from other similar water bodies was used. Choose ‘monitoring’ AND ‘grouping’ if the monitoring data for the water body was supplemented with monitoring data from other water bodies.
remoteSensing	Remote sensing	The status assessment was supported by Earth observation/remote sensing monitoring techniques.	This option can be combined with any of the following options: ‘monitoring’, ‘grouping’,’modelling’.
modelling	Modelling	The status assessment was based on modelling and/or statistical analysis.	This option can be combined with any of the following options: ‘monitoring’, ‘grouping’,’remoteSensing’.
expertJudgement	Expert judgement	The status assessment was based on expert judgement.	Select this option if there is no monitoring data available in this water body, and if monitoring data from other water were also not used, and if monitoring using remote sensing techniques was also not used. This option can NOT be combined with any other option.
notApplicable	Not applicable	This option is only valid if there was no assessment of the status (i.e. if the status is ‘unknown’).	This option can NOT be combined with any other option.

Table 48 Codelist - 4thCycle - AssessmentConfidence

Notation	Label	Definition	Notes
high	High confidence	«to-be-provided»	E.g. good monitoring data and a good conceptual model or understanding of the system based on information on its natural characteristics and its pressures
medium	Medium confidence	«to-be-provided»	E.g. limited or insufficiently robust monitoring data and expert judgement plays a significant role in assessment of status.
low	Low confidence	«to-be-provided»	E.g. no monitoring data, or no conceptual model or understanding of the system.
unknown	Unknown	No information about the confidence level of the status assessment.
notApplicable	Not applicable	Select this option if the status was not assessed.	This option is only valid if the status is ‘unknown’.

        ---
config:
  class:
    hideEmptyMembersBox: true
  layout: dagre
  theme: neutral
---
classDiagram
direction LR

class GroundwaterSurfacewaterLink{
<<enumeration>>
groundwaterDischargesToSurfaceWater
surfaceWaterRechargesGroundwater
bidirectionalWaterExchange
unknown
}

classDef default fill:white,stroke:#000;
classDef forFixing fill:white,stroke:#f00;

    

Figure 52 GroundwaterSurfaceWaterLink codelist - 4th cycle

Table 49 Codelist - 4th cycle - GroundwaterSurfaceWaterLink

Notation	Label	Definition
groundwaterToSurfaceWater	Groundwater discharges to surface water	«to-be-provided»
surfaceWaterToGroundwater	Surface water recharge groundwater	«to-be-provided»
bidirectionalWaterExchange	Bidirectional water exchange	«to-be-provided»
unknown	Unknown	Use this option in the information requested is not known.

        ---
config:
  class:
    hideEmptyMembersBox: true
  layout: dagre
  theme: neutral
---
classDiagram
direction LR

class ReasonForFailure{
<<enumeration>>
surfaceWater
groundWaterDependentTerrestrialEcosystem
salineOrOtherIntrusion
waterBalance
drinkingWaterProtectionArea
waterQualityAssessment
notApplicable
}

classDef default fill:white,stroke:#000;
classDef forFixing fill:white,stroke:#f00;

    

Figure 53 ReasonForFailure codelist - 4th cycle

Table 50 Codelist - 4th cycle - ReasonForFailure

Notation	Label	Definition	Notes
surfaceWater	Surface water	Failure to achieve Environmental Objectives (Article 4 WFD) for associated surface water bodies, resulting from anthropogenic water level alteration or change in flow conditions; significant diminution of the status of surface waters resulting from anthropogenic water level alteration or change in flow conditions.	This option is only valid if GroundWaterBody.linkToSurfaceWaterBody = 'yes'
groundWaterDependentTerrestrialEcosystem	Groundwater-dependent terrestrial ecosystems	Significant damage to groundwater-dependent terrestrial ecosystems resulting from an anthropogenic water level alteration.	This option is only valid if GroundWaterBody.linkTerrestrialEcosystem = 'yes'
salineOrOtherIntrusion	Saline or other intrusion	Regional saline or other intrusions resulting from anthropogenically induced sustained changes in flow direction.
waterBalance	Water balance	Exceedance of available groundwater resource by long-term annual average rate of abstraction, which may result in a decrease of groundwater levels.	This option is NOT a valid gwChemicalReasonsForFailure value.
drinkingWaterProtectionArea	Drinking water protected area	Deterioration in quality of waters for human consumption.	This option is only valid if there are Drinking Water Protection Areas associated with the water body. This option is NOT a valid gwQuantitativeReasonsForFailure value.
waterQualityAssessment	Water quality sssessment	Significant impairment of human uses and/or significant environmental risk from pollutants across the groundwater body.	This option is NOT a valid gwQuantitativeReasonsForFailure value.
notApplicable	Not applicable	This option MUST be used if the status is ‘good’ or ‘unknown’.	This option can NOT be combined with any other option.

See also:

• CIS Guidance Document 18 - Groundwater Status and Trends Assessment https://circabc.europa.eu/sd/a/8564a357-0e17-4619-bd76-a54a23fa7885/Guidance No 26 - GW risk assessment and conceptual models.pdf

• Technical report No. 6 - Technical report on groundwater dependent terrestrial ecosystems. http://bookshop.europa.eu/en/technical-report-on-groundwater-dependent-terrestrial-ecosystems-pbKHAV12006/

Todo

Groundwater - Topics that require discussion and clarification.

• Revision of the ImpactType codelist.

• Mapping tables to 3rd cycle codelists

Annexes - Data analysis - 3rd cycle

This section contains some of the exploratory data analysis that supported the revision of the data model.

It is not relevant for the understanding of the proposed model, but may be informative for data providers involved in the testing phase of the 4th cycle dataflows.

About the EEA discodata service

The example queries can be executed interactively in the EEA discodata service.
Note that some queries may timeout.
If you need to analyse the entire European dataset, download it in CSV format.
For example, the link https://discodata.eea.europa.eu/download/WISE_WFD/v2r1/GWB_GroundWaterBody downloads the data of the [WISE_WFD].[v2r1].[GWB_GroundWaterBody] table.

Geological formation

The WFD2016 and WFD2022 geologicalFormation attribute values are clearly similar to the Aquifer Type Code attribute (Table 51) in the International Hydrogeological Map of Europe 1:1,500,000 (IHME1500), although there is no reference to that source is made in the WFD Reporting Guidance documents.

A provisional spatial analysis of the two datasets (using only the topmost horizons) reveals limited agreement between the classifications.
In Figure 54, the rows represent the reported WFD geological formation and the columns represent the IHME aquifer type. The values show the percentage of the area of each WFD geological formation classified under each IHME aquifer type. For example:

• 48% of the area reported as ‘Fissured aquifers including karst - highly productive’ under WFD is similarly classified under IHME

• 33% of the area reported as ‘Fissured aquifers including karst - moderately productive’ under WFD is classified under IHME as ‘Practically non-aquiferous rocks, porous or fissured’.

In practice, this means that an existing pan-European hydrogeological map (IHME1500) can not be easily used to replace the information reported under WFD, but it also highlights the need for better clarification of the aquifer type and aquifer productivity values to be used in the 4th cycle.

Figure 54 WFD geological formation and IHME1500 aquifer type.

See detailed description

Table 51 International Hydrogeological Map of Europe 1:1,500,000 - Attributes

Column	Description	Example
AQUIF_CODE	Aquifer Type Code Code of the six classes of aquifer types specifying productivity and rock type of aquifers supplemented by areas covered by water or ice. Classification according to the Standard Legend for Hydrogeological Maps (SLHyM). 1: Highly productive porous aquifers, 2: Low and moderately productive porous aquifers 3: Highly productive fissured aquifers (including karstified rocks) 4: Low and moderately productive fissured aquifers (including karstified rocks) 5: Locally aquiferous rocks, porous or fissured 6: Practically non-aquiferous rocks, porous or fissured 200: Inland water 300: Snow field / ice field Remark: Aquifer type 1 and 2 include less frequently fissured-porous aquifers and aquifer type 3 and 4 include less frequently porous-fissured aquifers.	5
AQUIF_NAME	Aquifer Type Clear name of the six aquifer codes.	Highly productive porous aquifers
SALTINTRUS	Seawater Intrusion Aquifers influenced by seawater intrusion. 0: No influence 1: Seawater intrusion	0
LEVEL1	Lithology Level 1 Lithological description of mapping units after revision of the original map unit specifications. Method: Geometrical aggregation, translation of original lithological descriptions into a uniform lithological taxonomy scheme. Litho1 encompasses 229 classes of lithological descriptions.	Quartzites, sandstones, shales, volcanic rocks
LEVEL2	Lithology Level 2 Generalisation of LEVEL1 by further grouping of class descriptions. Method: Aggregation allowing only for primary and secondary consolidated and/or primary and secondary unconsolidated lithological components in each class description. Each class name starts with the primary consolidated lithological compound (if present). Litho2 encompasses 86 lithological classes.	Quartzites, sandstones
LEVEL3	Lithology Level 3 Generalisation of LEVEL2 by further grouping of class descriptions. Method: Aggregation allowing only for primary consolidated and/or primary unconsolidated lithological components in each class description. Each class name starts with the consolidated lithological compound (if present). Litho3 encompasses 29 lithological classes.	Quartzites
LEVEL4	Lithology Level 4 Aggregation forming 10 petrographic “supergroups”	Metamorphic rocks
LEVEL5	Lithology Level 5 Ternary class division referring to the degree of rock consolidation	Consolidated materials

Copyright: IHME1500 v1.2 © BGR & UNESCO 2019

Citation: BGR & UNESCO (eds.) (2019): International Hydrogeological Map of Europe 1:1,500,000 (IHME1500). Digital map data v1.2. Hannover/Paris

Source: Documentation of the digital vector dataset. Description of the attribute tables. Shapefile: ihme1500__ec4060_v12_poly

Aquifer productivity

See Figure 55: the CIS Guidance Document 2 does not provide quantitative guidelines, beyond the mention to the 10 m3/d threshold for drinking water abstraction. Does then the classification geologicalFormation = 'Insignificant aquifers' mean that the aquifer is not relevant in terms of potential yield, but is significant due to dependent surface water bodies, or groundwater dependent ecosystem? This should be clarified in the codelist definitions.

Figure 55 Criteria for definition of an aquifer (CIS Document 2).

National documents vary, when addressing productivity in terms of potential long-term abstraction rate.

Example - Ireland 2026 [1]:

“Yield is one of the main concerns in aquifer development projects, yields from existing wells are conceptually linked with the main aquifer categories:

• Regionally important (R) aquifers should have (or be capable of having) a large number of ‘excellent’ yields: in excess of approximately 400 m3/d.

• Locally important (L) aquifers are capable of ‘good’ well yields 100-400 m3/d.

• Poor (P) aquifers would generally have ‘moderate’ or ‘low’ well yields - less than 100 m3/d.”

Example - Scotland 2004 [5]:

“Productivity classes are a measure of the expected (i.e. potential) long-term abstraction rate of groundwater from a typical borehole at an individual abstraction site.”

Class	Range	Unit
Very high	(20,)	L/s
High	(10,20]	L/s
Moderate	(1,10]	L/s
Low	(0.1,1]	L/s
Very low	(0,0.1]	L/s

Reasons for failure

Show code

Example 25 [gwChemicalStatusValue] vs [gwChemicalReasonsForFailure] - 3rd cycle

-- https://discodata.eea.europa.eu/

SELECT [gwChemicalStatusValue]
  ,[gwChemicalReasonsForFailure]
  ,COUNT(DISTINCT [euGroundWaterBodyCode]) AS numberOfGroundWaterBodies
  ,COUNT(DISTINCT [countryCode]) AS numberOfCountries
FROM [WISE_WFD].[v2r1].[GWB_GroundWaterBody_gwChemicalReasonsForFailure]
WHERE [cYear] = 2022 AND [hasDescriptiveData] = 1
GROUP BY [gwChemicalStatusValue],[gwChemicalReasonsForFailure]

Show code

Example 26 Number of reasons for chemical failure - 3rd cycle

-- https://discodata.eea.europa.eu/
SELECT [numberOfReasonsForFailure],
COUNT(DISTINCT [euGroundWaterBodyCode]) AS [numberOfGroundWaterBodies],
COUNT(DISTINCT [countryCode]) AS [numberOfCountries]
FROM 
(
SELECT [countryCode],[euGroundWaterBodyCode]
  ,COUNT(DISTINCT [gwChemicalReasonsForFailure]) AS [numberOfReasonsForFailure]
FROM [WISE_WFD].[v2r1].[GWB_GroundWaterBody_gwChemicalReasonsForFailure]
WHERE [cYear] = 2022 AND [hasDescriptiveData] = 1 
GROUP BY [countryCode],[euGroundWaterBodyCode]
) AS a
GROUP BY [numberOfReasonsForFailure]

Show code

Example 27 [gwQuantitativeStatusValue] vs [gwQuantitativeReasonsForFailure] - 3rd cycle

-- https://discodata.eea.europa.eu/

SELECT [gwQuantitativeStatusValue]
  ,[gwQuantitativeReasonsForFailure]
  ,COUNT(DISTINCT [euGroundWaterBodyCode]) AS numberOfGroundWaterBodies
  ,COUNT(DISTINCT [countryCode]) AS numberOfCountries
FROM [WISE_WFD].[v2r1].[GWB_GroundWaterBody_gwQuantitativeReasonsForFailure]
WHERE [cYear] = 2022 AND [hasDescriptiveData] = 1
GROUP BY [gwQuantitativeStatusValue],[gwQuantitativeReasonsForFailure]

Show code

Example 28 Number of reasons for quantitative failure - 3rd cycle

-- https://discodata.eea.europa.eu/

SELECT [numberOfReasonsForFailure],
  COUNT(DISTINCT [euGroundWaterBodyCode]) AS numberOfGroundWaterBodies,
  COUNT(DISTINCT [countryCode]) AS numberOfCountries
FROM 
(
SELECT [countryCode],[euGroundWaterBodyCode]
  ,COUNT(DISTINCT [gwQuantitativeReasonsForFailure]) AS [numberOfReasonsForFailure]
FROM [WISE_WFD].[v2r1].[GWB_GroundWaterBody_gwQuantitativeReasonsForFailure]
WHERE [cYear] = 2022 AND [hasDescriptiveData] = 1 
GROUP BY [countryCode],[euGroundWaterBodyCode]
) AS a
GROUP BY [numberOfReasonsForFailure]

Natural background levels

In the 3rd cycle, natural background levels (NBL) were reported for 8608 water bodies (38.6%) and over 90 substances.

An exploratory analysis shows the expected high frequency of reporting of NBLs for metals and metalloids (e.g. arsenic, cadmium or lead), major ions and nutrients (e.g. chloride, sulphate, ammonium or nitrate) and physico-chemical parameters like electrical conductivity (likely as an indicator of saline intrusion).

Other parameters are more unexpected and are likely due to reporting errors (e.g. chlorite instead of chloride).

More importantly, the values reported are sometimes physically impossible (e.g. above 1000mg/L) or clearly unlikely.

See table

Table 52 GroundWaterBody - 3rd cycle - Parameters with reported Natural Background Level

parameterGroup	parameter	Countries	WaterBodies
Major Ions and Nutrients	CAS_18785-72-3 - Sulphate	19	4444
Major Ions and Nutrients	CAS_16887-00-6 - Chloride	20	4433
Major Ions and Nutrients	CAS_14798-03-9 - Ammonium	17	4328
Major Ions and Nutrients	CAS_14797-55-8 - Nitrate	11	4217
Major Ions and Nutrients	CAS_14265-44-2 - Phosphate	10	407
Major Ions and Nutrients	CAS_14797-65-0 - Nitrite	6	186
Major Ions and Nutrients	CAS_16984-48-8 - Fluoride	6	88
Major Ions and Nutrients	CAS_7440-09-7 - Potassium	4	80
Major Ions and Nutrients	CAS_7440-23-5 - Sodium	8	59
Major Ions and Nutrients	CAS_7723-14-0 - Total phosphorus	4	51
Major Ions and Nutrients	CAS_7439-95-4 - Magnesium	3	28
Major Ions and Nutrients	CAS_7440-70-2 - Calcium	3	28
Major Ions and Nutrients	CAS_71-52-3 - Hydrogen Carbonate (Bicarbonate) HCO3	2	26
Metals and Metalloids	CAS_7440-38-2 - Arsenic and its compounds	18	4514
Metals and Metalloids	CAS_7440-43-9 - Cadmium and its compounds	13	4301
Metals and Metalloids	CAS_7439-92-1 - Lead and its compounds	11	4257
Metals and Metalloids	CAS_7440-02-0 - Nickel and its compounds	15	4170
Metals and Metalloids	CAS_7439-97-6 - Mercury and its compounds	10	4155
Metals and Metalloids	CAS_7440-66-6 - Zinc and its compounds	8	3954
Metals and Metalloids	CAS_7440-47-3 - Chromium and its compounds	8	3947
Metals and Metalloids	CAS_7440-50-8 - Copper and its compounds	5	3906
Metals and Metalloids	CAS_7440-48-4 - Cobalt and its compounds	2	3772
Metals and Metalloids	CAS_7440-62-2 - Vanadium and its compounds	2	3772
Metals and Metalloids	CAS_7440-42-8 - Boron	7	139
Metals and Metalloids	CAS_7429-90-5 - Aluminium and its compounds	7	135
Metals and Metalloids	CAS_7439-89-6 - Iron and its compounds	6	128
Metals and Metalloids	CAS_7439-96-5 - Manganese and its compounds	6	118
Metals and Metalloids	CAS_7782-49-2 - Selenium and its compounds	4	79
Metals and Metalloids	CAS_7440-61-1 - Uranium	3	74
Metals and Metalloids	CAS_7440-39-3 - Barium	2	71
Metals and Metalloids	CAS_7439-98-7 - Molybdenum and its compounds	1	70
Metals and Metalloids	CAS_7440-28-0 - Thallium	1	70
Metals and Metalloids	CAS_7440-36-0 - Antimony	3	8
Metals and Metalloids	CAS_18540-29-9 - Chromium (VI)	1	2
Physicochemical Parameters	EEA_3142-01-6 - Electrical conductivity	14	4179
Physicochemical Parameters	EEA_3152-01-0 - pH	2	27
Physicochemical Parameters	EEA_3121-01-5 - Water temperature	1	1
undefined	CAS_14998-27-7 - Chlorite	1	138
undefined	CAS_1231244-60-2 - Metazachlor OA	1	70
undefined	CAS_172960-62-2 - Metazachlor ESA	1	70
undefined	CAS_67129-08-2 - Metazachlor	1	70
undefined	CAS_108-95-2 - Phenol	1	49
undefined	CAS_122-34-9 - Simazine	1	27
undefined	CAS_5915-41-3 - Terbuthylazine	1	27
undefined	CAS_1031-07-8 - Endosulfan sulfate	1	26
undefined	CAS_1066-51-9 - Aminomethylphosphonic acid (AMPA)	1	26
undefined	CAS_1071-83-6 - Glyphosate	1	26
undefined	CAS_118-74-1 - Hexachlorobenzene	1	26
undefined	CAS_152019-73-3 - Metolachlor OA	1	26
undefined	CAS_1582-09-8 - Trifluralin	1	26
undefined	CAS_15972-60-8 - Alachlor	1	26
undefined	CAS_1912-24-9 - Atrazine	1	26
undefined	CAS_2212-67-1 - Molinate	1	26
undefined	CAS_2921-88-2 - Chlorpyrifos	1	26
undefined	CAS_298-00-0 - Parathion-methyl	1	26
undefined	CAS_309-00-2 - Aldrin	1	26
undefined	CAS_330-54-1 - Diuron	1	26
undefined	CAS_33213-65-9 - Beta-Endosulfan	1	26
undefined	CAS_34123-59-6 - Isoproturon	1	26
undefined	CAS_3424-82-6 - o,p’-DDE	1	26
undefined	CAS_465-73-6 - Isodrin	1	26
undefined	CAS_470-90-6 - Chlorfenvinphos	1	26
undefined	CAS_50-29-3 - DDT, p,p’	1	26
undefined	CAS_53-19-0 - o,p’-DDD	1	26
undefined	CAS_56-38-2 - Parathion	1	26
undefined	CAS_60-57-1 - Dieldrin	1	26
undefined	CAS_608-73-1 - Hexachlorocyclohexane	1	26
undefined	CAS_608-93-5 - Pentachlorobenzene	1	26
undefined	CAS_72-20-8 - Endrin	1	26
undefined	CAS_72-55-9 - p,p’-DDE	1	26
undefined	CAS_76-44-8 - Heptachlor	1	26
undefined	CAS_87-86-5 - Pentachlorophenol	1	26
undefined	CAS_959-98-8 - Alpha-Endosulfan	1	26
undefined	EEA_32-03-1 - Total DDT (DDT, p,p’ + DDT, o,p’ + DDE, p,p’ + DDD, p,p’)	1	26
undefined	EEA_34-01-5 - Pesticides (Active substances in pesticides, including their relevant metabolites, degradation and reaction products)	2	17
undefined	CAS_64743-03-9 - Phenols	1	10
undefined	CAS_67-66-3 - Trichloromethane	1	9
undefined	EEA_3133-06-0 - Total organic carbon (TOC)	1	7
undefined	CAS_14866-68-3 - Chlorates	1	4
undefined	CAS_6190-65-4 - Desethylatrazine	1	4
undefined	EEA_33-42-1 - Total trichloroethylene + tetrachloroethylene	2	4
undefined	CAS_50-32-8 - Benzo(a)pyrene	1	3
undefined	EEA_33-19-2 - Mono basic phenols	1	2
undefined	CAS_124-48-1 - Dibromochlorometane	1	1
undefined	CAS_127-18-4 - Tetrachloroethylene	1	1
undefined	CAS_1333-82-0 - Chromium trioxide (CrO3)	1	1
undefined	CAS_79-01-6 - Trichloroethylene	1	1
undefined	CAS_86-73-7 - Fluorene	1	1
undefined	CAS_886-50-0 - Terbutryn	1	1
undefined	EEA_3133-04-8 - CODMn	1	1
undefined	EEA_33-05-6 - BTEX	1	1
undefined	EEA_33-29-4 - Surfactants (anionic)	1	1

Show code

Example 29 Substances for which natural background levels were reported - 3rd cycle

-- https://discodata.eea.europa.eu/
SELECT ISNULL(b.[parameterGroup],'undefined') AS [parameterGroup]
      ,[gwPollutantCode] AS [parameter]
      ,COUNT(DISTINCT [countryCode]) AS nCountries
      ,COUNT(DISTINCT [euGroundWaterBodyCode]) AS nWaterBodies
  FROM [WISE_WFD].[v2r1].[GWB_GroundWaterBody_GWPollutant] a
  LEFT JOIN (
  SELECT *
    FROM (VALUES
    ('Metals and Metalloids', 'CAS_7429-90-5', 'Aluminium and its compounds'),
    ('Metals and Metalloids', 'CAS_7440-36-0', 'Antimony'),
    ('Metals and Metalloids', 'CAS_7440-38-2', 'Arsenic and its compounds'),
    ('Metals and Metalloids', 'CAS_7440-39-3', 'Barium'),
    ('Metals and Metalloids', 'CAS_7440-42-8', 'Boron'),
    ('Metals and Metalloids', 'CAS_7440-43-9', 'Cadmium and its compounds'),
    ('Metals and Metalloids', 'CAS_7440-47-3', 'Chromium and its compounds'),
    ('Metals and Metalloids', 'CAS_18540-29-9', 'Chromium VI'),
    ('Metals and Metalloids', 'CAS_7440-48-4', 'Cobalt and its compounds'),
    ('Metals and Metalloids', 'CAS_7440-50-8', 'Copper and its compounds'),
    ('Metals and Metalloids', 'CAS_7439-89-6', 'Iron and its compounds'),
    ('Metals and Metalloids', 'CAS_7439-92-1', 'Lead and its compounds'),
    ('Metals and Metalloids', 'CAS_7439-96-5', 'Manganese and its compounds'),
    ('Metals and Metalloids', 'CAS_7439-97-6', 'Mercury and its compounds'),
    ('Metals and Metalloids', 'CAS_7439-98-7', 'Molybdenum and its compounds'),
    ('Metals and Metalloids', 'CAS_7440-28-0', 'Thallium'),
    ('Metals and Metalloids', 'CAS_7440-02-0', 'Nickel and its compounds'),
    ('Metals and Metalloids', 'CAS_7782-49-2', 'Selenium and its compounds'),
    ('Metals and Metalloids', 'CAS_7440-61-1', 'Uranium'),
    ('Metals and Metalloids', 'CAS_7440-62-2', 'Vanadium and its compounds'),
    ('Metals and Metalloids', 'CAS_7440-66-6', 'Zinc and its compounds'),
    ('Major Ions and Nutrients', 'CAS_14798-03-9', 'Ammonium'),
    ('Major Ions and Nutrients', 'CAS_7440-70-2', 'Calcium'),
    ('Major Ions and Nutrients', 'CAS_16887-00-6', 'Chloride'),
    ('Major Ions and Nutrients', 'CAS_16984-48-8', 'Fluoride'),
    ('Major Ions and Nutrients', 'CAS_71-52-3', 'Hydrogen Carbonate Bicarbonate HCO3'),
    ('Major Ions and Nutrients', 'CAS_7439-95-4', 'Magnesium'),
    ('Major Ions and Nutrients', 'CAS_14797-55-8', 'Nitrate'),
    ('Major Ions and Nutrients', 'CAS_14797-65-0', 'Nitrite'),
    ('Major Ions and Nutrients', 'CAS_14265-44-2', 'Phosphate'),
    ('Major Ions and Nutrients', 'CAS_7440-09-7', 'Potassium'),
    ('Major Ions and Nutrients', 'CAS_7440-23-5', 'Sodium'),
    ('Major Ions and Nutrients', 'CAS_18785-72-3', 'Sulphate'),
    ('Major Ions and Nutrients', 'CAS_7723-14-0', 'Total phosphorus'),
    ('Physico-chemical Parameters', 'EEA_3142-01-6', 'Electrical conductivity'),
    ('Physico-chemical Parameters', 'EEA_3152-01-0', 'pH'),
    ('Physico-chemical Parameters', 'EEA_3121-01-5', 'Water temperature')
) AS v(parameterGroup, parameterCode, name) ) b

    ON a.[gwPollutantCode] like b.parameterCode+' - %'

  WHERE a.[gwPollutantBackgroundLevelSet] = 'yes' 
      AND a.[cYear] = 2022 
      AND a.[hasDescriptiveData] = 1
      AND a.[gwPollutantCode] != 'EEA_00-00-0 - Other parameter'
  GROUP BY a.[gwPollutantCode]
      ,b.[parameterGroup]
  ORDER BY 1, 4 desc, a.[gwPollutantCode]

References

---

[1] (1,2)

Geological Survey Ireland. Aquifer classification. https://www.gsi.ie/en-ie/programmes-and-projects/groundwater/activities/understanding-ireland-groundwater/aquifer-classification/Pages/Aquifer-classification-how-to.aspx, 2026. Division of Department of Climate, Energy and the Environment.

[2]

M. D. Mastrandrea, C. B. Field, T. F. Stocker, O. Edenhofer, K. L. Ebi, D. J. Frame, H. Held, E. Kriegler, K. J. Mach, P. R. Matschoss, and G. K. Plattner. Guidance note for lead authors of the IPCC fifth assessment report on consistent treatment of uncertainties. Technical Report, Intergovernmental Panel on Climate Change (IPCC), 2010. URL: https://www.ipcc.ch/site/assets/uploads/2017/08/AR5_Uncertainty_Guidance_Note.pdf.

[3]

M. D. Mastrandrea, K. J. Mach, G. K. Plattner, and others. The IPCC AR5 guidance note on consistent treatment of uncertainties: a common approach across the working groups. Climatic Change, 108:675, 2011. doi:10.1007/s10584-011-0178-6.

[4]

A. Kause, W. Bruine de Bruin, J. Persson, and others. Confidence levels and likelihood terms in IPCC reports: a survey of experts from different scientific disciplines. Climatic Change, 173:2, 2022. doi:10.1007/s10584-022-03382-3.

[5]

A. M. MacDonald, D. F. Ball, and B. É. Ó Dochartaigh. A GIS of aquifer productivity in Scotland: explanatory notes. Technical Report Commissioned Report CR/04/047N, British Geological Survey, 2004. URL: https://nora.nerc.ac.uk/id/eprint/504764/1/CR-04-047N_SEPA\%20Aq\%20productivity.pdf.