Post on 06-Jul-2020
Vulnerability assessment of groundwater monitoring data and context setting for EU-wide, zonal and national registration
Ben Miles, BASF SE
17th European Modelling Workshop, Vienna22.10.2014
Background: FOCUS GW (European Commission 2014, coming into force in 2015)
For use of groundwater monitoring data at Tier 4 (EU or country level) there is requirement for quality criteria to be met, particularly
good characterisation of groundwater hydrology
demonstrating connectivity between treated topsoil and the point of sampling of the groundwater
demonstrating that relevant products have been used for a sufficient number of years in relation to the expected solute travel time to the aquifer (estimation should be robustly supported)
Overall exclusion of false negatives (and false positives)
27th European Modelling Workshop, Vienna22.10.2014
Background: FOCUS GW (European Commission 2014, coming into force in 2015)
At EU level, “a safe use” must be demonstrated to exist within the EU, covering a significant area in the context of one or more of the representative uses assessed
Reservations remain whether current knowledge on groundwater hydrology at the EU level, would be sufficient to use monitoring data to ever conclude that “safe use” might cover an extensive area for the EU evaluation
37th European Modelling Workshop, Vienna22.10.2014
How to address the requirements for use ofmonitoring data?
How can we address the quality criteria at the scale of individual monitoring sites?
Having demonstrated leaching vulnerability and connectivity of sampledwells to treated fields and excluded false negatives, how can we assessrepresentativity for a wider area of use (i.e. demonstrate safe use)?
Is lack of knowledge on groundwater hydrology at the EU level a significant problem?
47th European Modelling Workshop, Vienna22.10.2014
Combined approach working at different spatial scales
57th European Modelling Workshop, Vienna22.10.2014
Local scale:Monitoring site analysis
Combined analysis for RA showing relevance of monitoring data and setting monitoring sites/data in context for wider usage area (EU, Zone, Country…)
Large scale:Context setting, wider use area
What we use
What we want to achieve
What we get
What we do
monitoring site data monitoring results
monitoring site data GIS data
detailed hydrogeological site characterisation farmer surveys for product usage vulnerability assessments for wells Site specific modelling (soil column & aquifer)
GIS spatial analysis GW vulnerability mapping using both site
specific and latest EU-wide spatial data Relevance assessment in EU context
Representativeness in spatial context Comprehensive analysis:
use area – gwm sites – FOCUS scenarios
Vulnerability of monitoring sites Relevance of monitoring data Information on leaching behaviour
Work at two scales
What we use
What we want to achieve
What we get
What we do
In relation to current tiered assessmentscheme
67th European Modelling Workshop, Vienna22.10.2014
Approach combines Tier 4 with Tier 3b, includes elements of 3c and 3d
Monitoring site characterisation:Vulnerability and product applications
Monitoring site might be a monitoring well from existing public network ordedicated well installed at edge of field
For a monitoring well from existing public network the characterisation depends on available data
77th European Modelling Workshop, Vienna22.10.2014
Geological profiles,
hydrogeological characterisation,
identification of relevant fields and
farmer surveys for product applicationhistory
Monitoring site characterisation:Vulnerability and product applications
Monitoring site might be a monitoring well from existing public network ordedicated well installed at edge of field
For a monitoring well from existing public network the characterisation depends on available data
87th European Modelling Workshop, Vienna22.10.2014
Geological profiles,
hydrogeological characterisation,
identification of relevant fields and
farmer surveys for product applicationhistory
0.0
-5.15
Protective cover
Concrete foundation-0.6
-4.4
Man made
Gravely sand
-6.0
Boulder Clay
Ground surface
-0.8
+0.3
+0.8
Solid casing
Bentonite fill
Filter gravel
Slotted casing
Sump
Bentonite fill
-5.0
-4.5
-5.0
-5.5
-6.0
-1.3
-1.5
Construction DetailsBorehole Lithology
0.0
-5.15
Protective cover
Concrete foundation-0.6
-4.4
Man made
Gravely sand
-6.0
Boulder Clay
Ground surface
-0.8
+0.3
+0.8
Solid casing
Bentonite fill
Filter gravel
Slotted casing
Sump
Bentonite fill
-5.0
-4.5
-5.0
-5.5
-6.0
-1.3
-1.5
Construction DetailsBorehole Lithology
Monitoring site characterisation:Vulnerability and product applications
Monitoring site might be a monitoring well from existing public network ordedicated well installed at edge of field
For a monitoring well from existing public network the characterisation depends on available data
97th European Modelling Workshop, Vienna22.10.2014
Geological profiles,
hydrogeological characterisation,
identification of relevant fields and
farmer surveys for product applicationhistory
0.0
-5.15
Protective cover
Concrete foundation-0.6
-4.4
Man made
Gravely sand
-6.0
Boulder Clay
Ground surface
-0.8
+0.3
+0.8
Solid casing
Bentonite fill
Filter gravel
Slotted casing
Sump
Bentonite fill
-5.0
-4.5
-5.0
-5.5
-6.0
-1.3
-1.5
Construction DetailsBorehole Lithology
0.0
-5.15
Protective cover
Concrete foundation-0.6
-4.4
Man made
Gravely sand
-6.0
Boulder Clay
Ground surface
-0.8
+0.3
+0.8
Solid casing
Bentonite fill
Filter gravel
Slotted casing
Sump
Bentonite fill
-5.0
-4.5
-5.0
-5.5
-6.0
-1.3
-1.5
Construction DetailsBorehole Lithology
Monitoring site characterisation:Vulnerability and product applications
Monitoring site might be a monitoring well from existing public network ordedicated well installed at edge of field
For a monitoring well from existing public network the characterisation depends on available data
107th European Modelling Workshop, Vienna22.10.2014
Geological profiles,
hydrogeological characterisation,
identification of relevant fields and
farmer surveys for product applicationhistory
0.0
-5.15
Protective cover
Concrete foundation-0.6
-4.4
Man made
Gravely sand
-6.0
Boulder Clay
Ground surface
-0.8
+0.3
+0.8
Solid casing
Bentonite fill
Filter gravel
Slotted casing
Sump
Bentonite fill
-5.0
-4.5
-5.0
-5.5
-6.0
-1.3
-1.5
Construction DetailsBorehole Lithology
0.0
-5.15
Protective cover
Concrete foundation-0.6
-4.4
Man made
Gravely sand
-6.0
Boulder Clay
Ground surface
-0.8
+0.3
+0.8
Solid casing
Bentonite fill
Filter gravel
Slotted casing
Sump
Bentonite fill
-5.0
-4.5
-5.0
-5.5
-6.0
-1.3
-1.5
Construction DetailsBorehole Lithology
catchment
GW Flow
Monitoring site characterisation:Site specific modelling
Is the monitoring timeframe and sampling interval appropriate?
Can measured concentrations at the monitoring well be linked to known productapplications?
117th European Modelling Workshop, Vienna22.10.2014
CWeather, crop andapplication data
Leachingsimulation
GW flowHydrogeological data
time
GW flow andtransport model
Soil data
Monitoring site characterisation:Site specific modelling
Leaching models (e.g. PEARL) parameterised for the treated fields give us expected timeframe andconcentration signal for breakthrough at groundwater surface after application
To look at the expected concentration signal at the well for the monitoring period and make the link between measured concentrations and product applications 2D (or 3D) flow and transport simulationsfor the aquifer are appropriate
Output of field-specific leaching simulations used as boundary conditions for transport simulationsalong the flowpath to the well
127th European Modelling Workshop, Vienna22.10.2014
GW Well
Monitoring site characterisation:Summary
Detailed characterisation of monitoring sites addresses quality criteriarequirements for groundwater data, especially
good characterisation of groundwater hydrology
demonstrating connectivity between treated topsoil and the point of sampling of the groundwater
demonstrating that relevant products have been used for a sufficient number of years in relation to the expected solute travel time
Overall exclusion of false negatives (and false positives)
137th European Modelling Workshop, Vienna22.10.2014
Context setting, wider use area:Mapping monitoring locations to land use
147th European Modelling Workshop, Vienna22.10.2014
Demonstrate that monitoring locationsare in areas with intensive cultivationof target crop relative to proposedusage area
Product monitoring sites
Context setting, wider use area:Mapping monitoring locations to climatic zones
157th European Modelling Workshop, Vienna22.10.2014
Demonstrate that monitoring locationscover a range of climatic zones in Europe, relative to proposed usagearea
Product monitoring sites
Context setting, wider use area:Spatial modelling
167th European Modelling Workshop, Vienna22.10.2014
Approach: account for relevant processes of pesticide fate and movement through soil surface spatially distributed modelling
MetaPEARL: Metamodel of EuroPEARL (process based model) Consideration of sensitive processes and
parameters which are available as map data in GIS Climatic parameter: precipitation, temperature Soil parameters: water content, water flux,
organic matter, bulk density Substance parameters: DT50 and Kom
Proposed in FOCUS guidance for higher-tier exposure assessments
Context setting, wider use area:Spatial modelling
177th European Modelling Workshop, Vienna22.10.2014
Metamodel: Calculate relative leaching vulnerability for all OSR-relevant areas in EU
Context setting, wider use area:Determining relative vulnerability of sites
187th European Modelling Workshop, Vienna22.10.2014
Determine where the monitoringsites are positioned in relationto the vulnerability distributionfor all OSR producing areas bye.g. climate zone
Context setting, wider use area:Summary
197th European Modelling Workshop, Vienna22.10.2014
Context setting can be used to assess representativity of monitoring datafor a wider use area (country, zone, EU level)
Tier 3b is considered to be higher in the assessment scheme than Tiers 3c and 3d, taking a position between these and Monitoring Data at Tier 4
Tools for the assessment exist within the current regulatory framework(e.g. MetaPEARL)
For reliable risk assessment spatial datasets need to be of high qualityand transparent. Consensus needed on which data to use.
Conclusion
Combined approach of site assessment and spatial modelling fulfilsrequirements of guidance for monitoring data to be used in the registrationprocess and fits in current framework of tiered assessment
To fulfil the quality criteria for monitoring data, dedicated edge-of-fieldmonitoring wells have often advantages over wells from existing networks, however both can be used
If monitoring is carried out in generically vulnerable groundwater situationsit is not necessary to have detailed knowledge of hydrology at EU scale –it is sufficient to consider the potential for substances to leach from the soilcolumn.
Usefulness of spatial modelling depends on having agreed datasets ofsufficient quality and appropriate models
207th European Modelling Workshop, Vienna22.10.2014