1. The International Committee on Contaminated Land Management of Groundwater Quality in the Netherlands
Copenhagen, 4-5 October 2017

2. October 2017■ Copenhagen, Denmark■ www..iccl.ch
Outline
Characteristics of the Netherlands
Characteristics of soil and groundwater policy in the Netherlands
Area-oriented approach of the plumes
An example: the Rotterdam harbour
Conclusion
October 2017■ Copenhagen, Denmark■

3. Characteristics of the Netherlands
Delta of 4 internationals rivers
Soil: fine sediment of clay, sand and peat. Multi layered.
Shallow groundwaterlevels.
Groundwater flows.
Fresh water aquifers up to depth 700 meter, salt water aquifers up to depth of 900 meter
+/- 50% drinking water from groundwater resources
October 2017■ Copenhagen, Denmark■

4. Characteristics of the Netherlands
The Netherlands without dikes
Cooperation: the polder model, a cultural aspect in the fight against water
October 2017■ Copenhagen, Denmark■

5. Characteristics of the Netherlands
Fresh water aquifers up to depth 700 meter, salt water aquifers up to depth of 900 meter.
October 2017■ Copenhagen, Denmark■

6. Soil and groundwater policy (1)
Policy development since 1980’s after emerging site Lekkerkerk
Policy development: From multifunctional to risk based fit for use approach.
Owner of a site has the obligation to remediate
Distinction between new and historical contamination (1987)
Groundwater is included in definition contaminated site and part of soil legislation
Soil quality must comply with the current or future use
Policy goal is to reuse as much soil as possible
41 competent authorities for remediation
425 municipalities have a soil policy (excavated soils)
October 2017■ Copenhagen, Denmark■

7. Soil and groundwater policy (2)
Growing interest of using subsoil (energy, climate, water, spatial planning)
Remediation in the most sustainable and cost effective way
Presently focus on historical contamination with unacceptable risks
Towards a new environmental and spacial planning law where development determines the moment of remediation
Sustainable land management!
October 2017■ Copenhagen, Denmark■

8. Remediation policy: focus on sites with unacceptable risks
Period  unacceptable human risks
Period  unacceptable risks for the groundwater and ecology
End result of inventory:
400 human health
1400 migration to groundwater
200 ecology
October 2017■ Copenhagen, Denmark■

9. Urgent sites migration to groundwater
Historic contamination: the pollution originated before 1987
The quality of the groundwater exceeds the intervention values for groundwater
The volume of affected groundwater is over m3 and the annual increase in volume is over m3
There is a layer of contaminants on top or below the aquifer
Relation to vulnerable objects, defined according to the source-path-receptor model (water supply for human consumption, process water for industry or a protected area in accordance with the EU Water Framework Directory)
October 2017■ Copenhagen, Denmark■

10. Urgent sites migration to groundwater (2)
For the 1400 locations
Competent authorities:
Start of remediation before 2020
Integrated area-oriented approach of the plumes
Stimulate private owners to remediate their sites (source)
October 2017■ Copenhagen, Denmark■

11. October 2017■ Copenhagen, Denmark■ www..iccl.ch
Single plume; single owner => liability and responsibility is straight forward
October 2017■ Copenhagen, Denmark■

12. Urban inner city reality => source liability is clear, but who takes care of the plumes?
Drinking water extraction
Parking garage
Metro tunnels
ATES
Multi party monitoring of intermingled plumes

13. Bottlenecks for remediation of groundwater plumes
urban areas often contain large mixed plumes
who is liable?
often no technical or cost effective solution available, since plumes are located under city centers
therefore there is no incentive to remediate these sites
dispersion of the contamination is influenced by other functions of the subsoil
municipalities want to make an integrated comparative assessment by developing an urban area.
a change in addressing the liability is needed
an incentive is needed to reach the policy goal
October 2017■ Copenhagen, Denmark■

14. Area oriented approach
Integrated management and monitoring 13

15. October 2017■ Copenhagen, Denmark■ www..iccl.ch
Solutions 1. Owner
disconnect source from plume
the owner has to remediate the source by existing legislation
transfer the liability for the plumes to a public organization
owner sells the plume (redemption money) and is no longer liable
October 2017■ Copenhagen, Denmark■

16. Solutions 2. Public organization
Government is responsible for groundwater and has the instruments to organize an area oriented approach
For the mixed plumes up scaling to an area is needed
Competent authority has to make a (management) plan => including the permissible value of the contamination on the borders (target values, intervention values, …)
Public consultation is obliged
Financial agreements:
Urban (re)development is mostly the
driver so other stakeholders have an
interest
area oriented approach
October 2017■ Copenhagen, Denmark■

17. Area-oriented approach of the plumes
Define the total area
Only for historic contamination!! Contamination originating after 1987 must be remediated directly by polluter
Risk management in stead of remediation on an area level
Monitoring on the border of the area and if necessary take remediation measures at borders or plane of compliance (poc)
Dispersion within the area is allowed; the quality of the groundwater must comply with the functions of the subsoil
reduces costs 50% (average)
October 2017■ Copenhagen, Denmark■

18. An Example: the Rotterdam Harbour
October 2017■ Copenhagen, Denmark■

19. An Example: the Rotterdam Harbour (2)
October 2017■ Copenhagen, Denmark■

20. October 2017■ Copenhagen, Denmark■ www..iccl.ch
Conceptual Model
October 2017■ Copenhagen, Denmark■

21. October 2017■ Copenhagen, Denmark■ www..iccl.ch
Conceptual Site Model
Contaminant distribution
Availability of representative field data (from databases and industry)
Priority contaminants
Related to industrial activities
Geohydrology
Regional scale
Complex soil stratification
Influence of heterogeneities (sand piles, groundwater extractions)
Natural attenuation
Very important for long travelling times
Redox conditions
Biodegradation rates from representative field studies
Modeling of future impacts
at receptors (Monte-Carlo)
October 2017■ Copenhagen, Denmark■

22. October 2017■ Copenhagen, Denmark■ www..iccl.ch
3rd plane of compliance
October 2017■ Copenhagen, Denmark■

23. 3rd plane of compliance (2)
October 2017■ Copenhagen, Denmark■

24. Result risk assessment
Impact to surface water (1st plane of compliance):
contaminant flux from the groundwater is small compared to other emission sources
concentration within the surface water remains well below norms
Impact to aquifer (2nd plane of compliance)
already considerable (8% of the aquifer impacted) and gradually increasing (to 12% in 2040)
aquifer has limited use (brackish to salt water)
Impact to adjacent groundwater systems (3rd plane of compliance)
relatively limited now (3% of the border impacted) but strongly increasing (to 8% in 2030 and 10% in 2050)
October 2017■ Copenhagen, Denmark■

25. October 2017■ Copenhagen, Denmark■ www..iccl.ch

26. October 2017■ Copenhagen, Denmark■ www..iccl.ch
Conclusions
Advantages of area oriented approach
Protection of residential area and farms
Use of natural resilience
Optimization of monitoring
Cost-effective
Modeling gives insight in risks and measures
Area oriented approach is a cost effective and sustainable way of risk based management!
October 2017■ Copenhagen, Denmark■