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TRANSCRIPT
Monitoring & Sampling Uncertainty
associated with the
Water Framework Directive
Simon O’Toole
Environmental Protection Agency.
TERRITORIES Workshop, Madrid, June 13-14, 2018.
Presentation outline
1. Water Framework Directive (WFD) Introduction
o WFD Purpose & Status Objectives; surface water status assessment
o Priority (Hazardous) Substances, Specific Pollutants
2. Monitoring Design
o Operational, Surveillance & Investigative monitoring
3. Sampling Strategy
o Techniques for Water and Biota sampling
4. Analytical Techniques
o Water, Biota & Sediment analysis
o QA/QC Directive
o Novel Techniques - Passive Sampling & Effects Directed Analysis
5. Environmental Risk Assessment
6. Conclusion
1. The Water Framework Directive
2000/60/EC
Water
Framework
Directive
To protect all waters of the
hydrological cycle
Coordinated and integrated water management across EU
Inland surface waters, transitional waters, groundwaters and coastal waters to achieve ‘‘good status’’
‘Good water status’” includes the requirement for “good chemical status” and “good ecological status”
1. WFD interaction with other EU Legislation
& River Basin Management Plans
Water Framework Directive
Drinking Water Bathing
Water
Urban Waste Water
IPPC
Env. Impact Assess
Major Accidents
FloodsMSFD
Sust. Pesticide
Use
Nitrates
Sewage Sludge
Birds
Habitats
1. WFD Status Objectives:
Surface water status assessment
Chemical Status
Priority Substances
(Annex X)
Priority Hazardous Substances
(Annex X)
Ecological Status
Specific Pollutants
(Annex VIII)
&
Substances selected & EQS applied at EU level;45 Subs (metals, PPPs, PAHs, PBDEs) Substances
identified & EQS derived by individual MSs; X Subs
Biological & Physico-chemical Elements
2. WFD Monitoring Design
Operational, Surveillance & Investigative
Operational
Status or changes in status of waters
at risk
Surveillance
Long-term
changes/ impacts
from human activity
Investigative
Exceedances are unknown
Magnitude/impacts of pollution
2. Monitoring Design;
Location & frequency – Where & When?
o The sampling site should be representative of pressures and impacts
o Link to the objective of the program (Op./Surv./Invest.)
o Different stations for different substance groups?
o Considerations from usage and properties of the substances
o Pollution pressures from diffuse/point sources (intermittent releases)
o Land use and population
o Industrial or urban wastewater effluents
o Bed-sediment re-suspension
o Spatial variations of agri-chemicals in water and sediment follow their
application patterns (temporal)
o Easily degradable chemicals quickly disappear downstream from sources
o Hydromorphological and hydrological conditions
o Navigation, flood protection, drinking water supply, power generation,
irrigation and recreation
2. WFD Monitoring Design;
Temporal fluctuations - seasonality
o Seasonality of water discharge
o Low flow periods result in enhanced signals from stationary sources such
as WWTPs, industrial emissions
o Seasonality of application/use
o Antibiotics, sunscreen, pesticides
o Seasonality of mobilisation
o Atmospheric pollutants mobilised with snowmelt runoff
o Plant Protection Products mobilised with precipitation events
o Persistent compounds (Dioxins, PCBs) mobilised from bottom sediment
and floodplains during extreme events.
o Stability of the compounds
o Less degradation in colder period
o Compartment selection
o Seasonality is higher in water than in sediments
3. Sampling Strategies
Details to be considered for a Sampling Plan
Sampling Strategy
Sample Types
Sample Equipment
Sample Preservation
Sample Handling
Sample Transport Analysis
WFD Operational Monitoring
o 2L plastic bottles - general components
o On-site measurements; DO, pH, cond.,
Temp., on-site filtration for chlorophyll
o Lake sampling a mix of shore & boat
sampling
o Some additional monitoring needed
(depth parameters)
o ~1500 River & Lake sites, 5 times p.a.
WFD Surveillance Monitoring
o Sampling for general components
o Priority Substances at all sites; VOCs - 40 ml
glass vials, Metals - on-site syringe filtration
preserved to pH 2, DOC - on-site syringe
filtration, organic substances - 1 x 2.5L amber
glass bottle & 1 x 250ml amber glass-
stoppered bottle
o ~400 River and Lake sites monthly
3. Sampling Strategies;
Sample handling & Preservation
o Decomposition
o Temperature, UV irradiation, microbial activity and chemical reactions with
external agents (O2, CO2)
o Sample containers
o Silanized glass - increases hydrophobicity - prevents adhesion
o Pre-rinsing with extraction solvent, DI H2O, acetone rinsing - prevents
carryover
o Losses from volatilisation – Exclude air
o Several approaches have been applied to preserve sample integrity:
o Protecting samples from external agents (using brown-glass containers)
o Addition of preservatives should not interfere with target analyte
o Acidification/buffering
o Transport at 4oC
o Refrigerate water samples, freeze sediment and biota samples (≤-20°C)
3. Sampling Strategies
Quality Control
o Effective cleaning can be demonstrated by regular comparison of field
and laboratory blanks
o Samples can be buffered at pH 7 for common conservation procedures
(multi-residual analysis)
o Extract samples within 7 days or 48hrs if sample pH has not been
modified
o Extracts adsorbed on Solid Phase Extraction (SPE) should be stored
frozen (≤-20°C), analyse within 30 days
o Reanalyse selected samples after a holding time twice as long as that
for the original sample, to demonstrate the integrity of the sample pre-
treatment
4. Analytical Techniques
o Water analysis
o pH & conductivity, BOD, COD, TOC, alkalinity, hardness, turbidity, salinity,
colour, suspended solids, chlorophyll
o Silica, total phosphorous, total nitrogen, nutrients (PO4, NH3, NO3, NO2)
o Sulphate, fluoride, chloride, hexavalent chromium
o Metals (ICP-MS)
o PAHs (GC-MS), Pesticides & Herbicides (LC-MS/MS), VOCs (GC-MS)
o QA/QC Directive 2009/90/EC; laying down…technical specifications for
chemical analysis and monitoring of water status
o Method Validation; ISO 17025 standard
o LOQ (quantification limit) ≤ 1/3 EQS
o UoM (relative uncertainty, k=2) ≤ 50% at EQS level
o Participation in proficiency testing programs/Inter Lab Comparisons
o Sediment - Generally investigative/trend monitoring, no EQSSediment
4. Analytical Techniques
Biota monitoring
o Biota analysis
o Monitoring based on “wild” fish
o No common ‘Euro-fish’; different biota in different MS, how to standardise
and compare data?
o Whole fish homogenates comprising a minimum of 10 individual size-
classed fish
o Normalise; size (age)/trophic level, lipid content, dry weight,
gender, protection goal – EQSbiota, hh/EQSbiota, sec pois
o Whole soft body of blue mussels - minimum of 50 mussels,
general size range 4-6 cm
o Bioconcentration/Bioaccumulation/Biomagnification
o Requires evaluation and validation of bioaccumulation data
Guidance Document No. 32 on Biota Monitoring under the WFD
4. Analytical Techniques
Passive Sampling
Passive Sampling devices; in-situ collection of a time-integrated average of
dissolved contaminants;
o Consist of sampling materials mounted or contained within a frame or
support
o Two methods of passive sampling; partition and adsorption
o Linear up-take of substances from weeks to months for different sorbent
materials
o POCIS and SPMD often used in conjunction; cover different Log Kow ranges
o Diffusive gradients in thin films (DGT); metals (& RNs)
Selection
Deployment
Retrieval
Extraction & analysis;
PS derived Cw
Exposure
4. Analytical Techniques
Effects Directed Analysis (EDA)
o Effects-directed analysis;
o not feasible to analyse and
evaluate all substances,
including risks from
cumulative exposure, by a
chemical approach alone
o isolate and identify major
toxicants in complex
mixtures causing adverse
effects
o Biological analysis;
o Bioassays (in vitro and in
vivo)
o Biomarkers
o Ecological indicators
EC Technical Report on Aquatic Effect-based Monitoring Tools 2014 - 077
5. Uncertainty in Environmental Risk
Assessment (ERA)
o EQS(PNEC) = Most reliable ecotox data (µg/L) / Assessment Factor
o Uncertainty is accounted for by the use of Assessment Factors (AF)
o Generation of additional ecotoxicity data reduces the size of the AF,
corresponding to more robust EQSs
o Where uncertainty is high, larger AFs are necessary
o AFs – 1 to 1000
o ERA Risk Quotient = Exposure/Toxicity
o RQ = MEC/EQS (PEC/PNEC)
o If RQ < 1; acceptable risk
o If RQ ≥ 1; non acceptable risk – implement measures
o Inappropriate representation of uncertainty may lead to underestimation
of risk
6. Conclusions
o Sampling can make a significant contribution to overall uncertainty of
measurement
o While sampling protocols have been developed (ISO 5667), uncertainty
from sampling has often been ignored and seldom validated
o Biota monitoring & Passive Sampling
o Biota monitoring determines dissolved phase concentrations – biological
variation, difficult to quantity
o Passive Sampling – method uncertainty – quantifiable
o Passive Sampling could be used as a proxy for biota monitoring
o Use of Passive Sampling in tiered Risk Assessment (trigger levels)
o Mixtures not evaluated - Use of EDA to monitor mixture toxicity (1+1≠ 2),
to assess Mode of Action of substance groups (estrogenicity)
o Use of EDA on Passive Sampling extracts
