Implementing EU legislation in the
regional groundwater quantity and
quality policy of Flanders
Griet Heuvelmans
[email protected]
Flemish Environment Agency
European groundwater legislation
Water Framework Directive (WFD)
Defines ‘good status’ for groundwater quantity and quality
Obligation to develop river basin management plans
Groundwater Directive (GWD)
Further specifications for chemical status assessment
Refinement of concepts and methodology
Annexes with lists of substances that need to be considered
Periodic review and revision
2014: list of substances revised (Fosfate, Nitrite)
‘Watch list’ for emerging pollutants under construction
Directives on nitrates, pesticides, drinking water
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Planning cycle of WFD
Delineate
groundwater bodies
6 year cycle
Assess pressure and
impact
Formulate
measures
Assign function
and set standards
Assess status
Delineation of groundwater bodies
HCOV: Hydrogeological
Code of Flanders
Hydrogeological
code
Hydrogeological
maps
Fault
3D hydrogeological maps
(depth, thickness)
Administrative
boundary
Isolated sequences of
aquifers and aquitards
Groundwater
systems
Groundwater
bodies (GWB)
CVS_0800_GWL_1
Management units
CVS_0800_GWL_2
CVS_0800_GWL_3
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Quantitative pressure
Quantitative pressure
Phreatic and confined
abstractions, relatively
small abstraction rates
Groundwater
scarcity
Groundwater
scarcity
Mainly phreatic
abstractions
Phreatic and confined
abstractions
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Qualitative pressure
Diffuse sources versus point sources
Most important diffuse sources in Flanders:
Manure
Pesticides
Heavy metals (historical industrial emissions)
Relation with other EU directives (nitrate, pesticides)
Impact of quantitative pressure on groundwater quality:
Saline intrusion
Changing redox conditions in confined aquifers
Functions, protected areas and
environmental standards
Most GWB in Flanders serve different functions
Protected areas (parts of groundwater bodies)
Around public drinking water production sites
Groundwater dependent terrestrial ecosystems (GWDTE)
Environmental standards:
Quantity:
water balance, salt water intrusion, GWDTE, baseflow
Quality:
Environmental standard: max. conc. for specific end-user
Natural background value: ‘natural’ conc for specific GWB
Threshold value: for evaluating the need for action
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Environmental standard, natural
background values and status
http://nfp-at.eionet.europa.eu/Public/irc/eionetcircle/bridge/library?l=/deliverables/bridge_groundw-205pdf/_EN_1.0_&a=d
In case of ‘bad’ natural
quality: limits on
groundwater applicability
in spite of compliance with
environmental standards
and good status of GWB
Examples:
As in Campine region
B, Cl, Na, … in
coastal and some
confined GWB
Primary monitoring network
Primary monitoring network:
Screens in all aquifers that
are used for water
production (phreatic and
confined GWB)
In total: 830 screens
Monthly gw level
measurements
Yearly sampling and
quality analysis
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Phreatic monitoring network
Phreatic monitoring network:
Limited to phreatic GWB
Standard installation:
multilevel well with 3
screens in different redox
zones
Well depth: 2 - 100 m
In total > 5000 screens
6-monthly gw level
measurement and quality
analysis
Dissemination of data
All monitoring data are freely available
Dissemination via ‘DOV’ (database of the subsurface in
Flanders) web portal: dov.vlaanderen.be
Groundwater level data
Groundwater quality data
Hydrogeological maps
Protection zones
Drilling reports
Cone penetration tests
…
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Qualitative status assessment
9/42 GWB in good qualitative status (ref. year 2012)
Main problems:
Phreatic GWB:
Almost all GWB: pesticide and manure (NO3, K, …)
GWB in Campine region: heavy metals (As, Ni, …)
Confined GWB: qualitative problems are related to
(over)exploitation
Redox reactions: e.g. pyrite oxidation produces SO4
Salt water intrusion: e.g. Cl, EC
Example: Pesticides (2014)
In 2014, > 40 substances were analysed in all samples
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Quantitative status assessment
Phreatic GWB in a good status (ref. year 2012)
8 confined GWB are in a bad status (ref. year 2012):
Because exploitation might lead to salt water intrusion
Natural flow
direction
Actual flow
direction
Due to change in flow direction,
natural freshening of aquifer is
slowed down or reversed
Quantitative status assessment
8 confined GWB are in a bad status:
Because exploitation might lead to salt water intrusion
Because exploitation might lead to oxic conditions
Example: Paleocene aquifer (Landenian)
In this zone, overexploitation
might induce oxic conditions in
the confined aquifer
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Quantitative status assessment
8 confined GWB are in a bad status:
Because exploitation might lead to salt water intrusion
Because exploitation might lead to oxic conditions
Because of long-term declining trends of hydraulic heads
Well 4-0056 in HCOV 1300
Well 7-0234 in HCOV 0400
Remediation measures
For groundwater quality: Interference with other environmental
directives and action plans
Nitrate directive and ‘MAP’ (manure action plan)
Pesticide directive and ‘VAP’ (Flemish action plan for
pesticide reduction)
For groundwater quantity:
Reduce groundwater abstractions from confined aquifers
Scenario-analyses with models to substantiate measures
Development of ‘restoration programs’
In both cases: groundwater systems respond slowly to measures
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Principles of the restoration programs
Initially designed for guiding the permitting process
Spatially differentiated action programs:
Delineate ‘action zones’ and ‘attention zones’ for GWB in
bad quantitative status based on scenario analyses
No fixed, linear reduction of abstractions, but prioritise action
(allocate groundwater) in function of:
Required water quality: practical and legal restrictions
Possibilities for water saving: technological advances
Availability of alternative water sources: rainwater, shallow
(phreatic) groundwater, surface water
Example: Landenian aquifer system
4 action zones with different measures (take action where
needed)
Action zone 3:
Stand still
Action zone 4: Limited
expansion allowed
Action zone 2:
More limited
reduction
Action zone 1:
Large reduction
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Example: Oligocene aquifer system
Action zone in Oligocene aquifer system: more restrictive
permitting if alternative groundwater source is available
No alternative groundwater
source (salt water)
Phreatic groundwater is
potential alternative
No alternative groundwater
source (transmissivity too low)
Complementary measures
Action and attention zones were initially designed for
supporting the permitting process
The zones will additionally be used for:
Adjust existing groundwater taxation zones
Prioritise environmental inspections
Perform pilots for the detection of illegal groundwater
abstractions
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