1. Drinking Water Protected Areas: Luxembourg Experiences
22nd Working Group C Plenary Meeting Brussels
21/03/2012
Tom SCHAUL
Administration de la gestion de l’eau
Grand-Duché Luxembourg

2. 0. Overview Transposition of EU Groundwater Directive Luxembourg
- Legal Act
- Delineation of Groundwater Bodies
- Status
Drinking Water Protected Areas (DWPA), Luxembourg
- Groundwater as Drinkwater resource
- Drinking Water Protection Zones:
- History
- Methodologies
- Actual re-delineation
- Challenges
3. Discussions relative to Guidance Document No16

3. 1. GWD-Luxembourg: Legal Act
Règlement grand-ducal du 08 juillet 2010 relatif à la protection
des eaux souterraines
Quality standards
Threshold values 3

4. 1.GWD-Luxembourg: Delineation of Groundwater Bodies
- based on 10 Hard Rock (sediment deposits)
aquifers responding to WFD criterias
- delineation according to geological criterias
and hydrogeological understandings
 homogeneous geological units
31 monitoring stations 4

5. 1.GWD-Luxembourg: Delineation of Groundwater Bodies
Transboundary GWB with France, Germany, Belgium (Rhine river basin) 5

6. 1.GWD-Luxembourg: Status
2 out 5 GWB in poor chemical status:
(1) nitrates
(2) pesticides
Most common Pesticides:
+ Metolachlore ESA A
Desethyl-Atrazine (58%) B
Atrazine (53 %) C
Dichlorbenzamide (49 %) D
Bentazone (28%) E
N,N-Dimethylsulfamide (4 %) F
Desisopropyl-atrazine (3 %) 20 40 60 80
200
400
600
Pesticide concentration [ng/l] 6

7. 2.DWPA: Groundwater as Drinkingwater Luxembourg
2/3 of drinking water from groundwater
(78 000m3/day)
336 Abstraction points:
75% springs / 25% drillings
+/- 1% with treatement due to human made pollution
Muschelkalk
Luxemburger Sandstein
Bundsandstein
Mittlerer Lias
Dogger
Devonschiefer 7

8. 2.DWPA: Groundwater as Drinkingwater resource, LU
Sediment deposits / fissured aquifers
Main aquifer: Luxembourg Sandstone
( > 80% of ressources)
 partially rapid flow / high vulnerability 8

9. 2. DWPA: Identification and Delineation Luxembourg
Protection zones ( zones de protection-ZPS):
(1) Identified in River Management Basin Plan
(19 out of monitoring stations in ZPS)
- No binding legal act
(2) Re-delineation according to
- National Water Law of 2008:
- creation of binding legal acts
- at latest by end 2015
- 2012: binding legal act
defining measures in all ZPS
- Risk approach / vulnerability mapping 9

10. 2.DWPA: Identification and Delineation Luxembourg
Protection zones (ZPS):
- part of a groundwater body
« Safeguard zones » according to art.7 WFD
Second interpretation of
Guidance Document 16
with focused protection measures
(in accordance with DW obligations)
+ focused monitoring 10

11. 2.DWPA: Identification and Delineation Luxembourg
According to guidance document No16:
DWPA:
- whole groundwater bodies
- cover:
(1) Safeguard zones:
(2) Zones of potential abstraction
LU: Zones of potential abstraction
Possible delineation according to water law
Actually no zones identified
Delineation not always useful 11

12. 2. DWPA: Identification and Delineation Luxembourg
Delineation of zones of potential abstraction not useful:
Example: Confined aquifer of Luxembourg Sandstone:
DW exploitation sites for emergency cases 12

13. 2. DWPA: Identification and Delineation Luxembourg
Example: Confined aquifer of Luxembourg Sandstone:
Results of numerical modelisation study
No additional abstraction possible
Over-exploitation and hence
poor quantitative status
Delimitation of «  safeguard zones »
But: no delimitation of
zones of potential abstraction
 DWPA = GWB ?
Map representing numerical simulation of GW-drawdown due to additional abstraction 13

14. 2. Actual Re-Delineation of « Zones de protection »
Consideration of hydrogeological properties:
Fissured aquifers with preferential infiltrations
and flows
Risk based approach
Vulnerability mapping 14

15. 2. Actual Re-Delineation of » Zones de protection »
Harmonized methodology of delineation based
on a national guideline:
Vulnerability approach
Stepwise:
Catchment characteristics (quality, hydraulics,…)
=> Mapping + field investigations
Orientated on German Guideline DVGW W101 and
international guidelines in fissured/karstic
aquifers (eg Cost620, Switzerland) 15

16. 2. Actual Re-Delineation of » Zones de protection »
Example: Spring catchement with high risk ( high vulnerability)
ZIII: Wider protection zone (catchment area)
ZII: Closer protection zone ( 50 days travel time)
ZII-V1: Closer protection zone with higher vulnerability
(preferential flows, infiltrations)
ZI: Immediate protection zone
(20 meters upgradient to catchment ) 16

17. 2. Actual Re-Delineation of » Zones de protection »
Example: Abstraction boreholes in a confined aquifer (low vulnerability)
 good protection
no closer protection zone
wider protection zone
delineation:
- according to abstraction regime
(limited to 4 month/year)
- consideration of increasing
future abstraction rate
- numerical modelling
 Additional monitoring wells
Wider protection
Zone (+/-2km)
Abstraction boreholes
Additional monitoring wells 17

18. 2. Actual Re-Delineation of » Zones de protection »
Risk categories according to table 1 GD- N016
Delimitation of protection zones LU
Monitoring and measures
Type 1:
Low Risk, General Protection Zones
- Wider Pz
- Specific monitoring possible (additionnal stations, frequences)
- Measures related to type of zone
Type 2:
Moderate Risk
Precautionary Protection
- Wider PZ
- Closer PZ
- Specific monitoring possible(additionnal stations, frequences)
Type 3:
High Risk
Specific Protection
- High
vulnerability PZ 18

19. 2. Actual Re-Delineation of » Zones de protection »
Example: Abstraction spring catchments (Lux. Sandstone)
Challenging situations:
Rapid transit times (up to 60m/ hour)
No preferential infiltration
Depth groundwater table at depth of 30-60m
Identification of high risk zone ( ZII-V1)  difficult
Very large extension of zone II ( 50 days transit times) 19

20. 3. Discussions relative to Guidance Document No16
Delineation of zones of potential abstraction not always useful
«DWPAs are whole groundwater bodies » ?
Further guidances in relation to risk based approach.
More experience exchanges eg. with case studies spring catchment and specific hydrogeological settings (eg fissured aquifers).
Harmonized methodology in transboundary GWB. 20

21. Thank you! 21