An overview of water quality monitoring schemes for compliance with the WFD

An Overview Michael Jackman Chemical Expert

Module 2: Water Budget, Pressures and Impacts, Significant Water Management

Issues, Monitoring, Characterization Report

Monitoring Schemes according to EU Water Framework Directive

1) Surveillance2) Operational3) Investigative

1) Surveillance Monitoring

An initial baseline assessment of the water basin.

Monitor the impacts of natural conditions and anthropogenic activities. E.g. long range transport and deposition of pollutants from the atmosphere

Supplementing and validating the Annex II risk assessment procedure.

The assessment of long-term changes in natural conditions especially of reference sites;

From this derive:The efficient and effective design of future monitoring programmes which can highlight water quality trends.

Sufficient water bodies should be monitored to provide an assessment of the overall surface water status within each catchment and sub-catchment of the river basin district.

Monitoring should be carried out at least at the points where:The volume of water present is significant within the river basin district, including large lakes and reservoirs.

Significant bodies of water cross a Member State boundary;At such other sites as are required to estimate the pollutant load which is transferred across Member States boundaries,

At points where the water is transferred into the marine environment.

Sampling Pointss

Selection of Support Quality Elements

Any priority list substances discharged into the river basin or sub-basins must be monitored.

Other pollutants also need to be monitored if they are discharged in significant quantities in the river basin or sub-basin.

The selection should also be derived from information on the ecological status where indications of toxic impacts are found or from ecotoxicological evidence.

Biological Quality elements

Biological quality elements are the core of WFD compliant monitoring of ecological status. The development of national methods or the adaptation of existing methods to the specific regional conditions is of utmost importance for comparability and consistency of IRBM.

The national BQE methods are not only a formal requirement for the WFD but they are the new benchmark for almost all aspects of future international water management with the continued assessment of chemical status.

Therefore, the development and continuous improvement of assessment methods needs specific attention.

Frequency Of Surveillance Monitoring

Surveillance monitoring must be carried out for each monitoring site for at least a period of one year all biological quality elements and all general physico-chemical quality elements.

Frequency of Physico-Chemical Sampling

Frequency of BQE Sampling

Timing of sampling

Samples should therefore be taken at times which will adequately represent the quality and its variations with minimum effort. The sampling programme should be designed to account for seasonal and diurnal cycles and consider business week cycles, random or transient events, and long-term persistence or trends.

It might be necessary to increase sampling frequency while abnormal conditions persist, for example, during process plant start-up, during flood conditions in a river or at times of algal blooms

2) Operational Monitoring

The national river basin management scheme to monitor water bodies that are at risk.

The location of the sampling points for operational monitoring ideally should points where there is a change in the water source conditions e.g. after a major effluent producer .

Selection of monitoring sites

Operational monitoring has to be undertaken for all water bodies that have been identified by the risk assessment

From the results of the surveillance monitoring, as being at risk of failing

All water bodies into which priority substances

Quality elements for Operational Monitoring

Monitor for those biological elements most sensitive to the known pressures

E.g. for organic pollution then benthic invertebrates might be the most sensitive indicator

Non-biological indicators

Non biological quality element may complement the use of biological indicators but it cannot replace it.

However of non-biological indicators (such as physicochemical parameters) can be used operationally to derive limits to reduce pressures (e.g. discharges from Urban Waste Water

Treatment Works) are related to specific physico-chemical parameters (e.g. total organic carbon, BOD or nutrients). In this case one could monitor non-biological indicators and other biological indicators (e.g. benthic invertebrates) at different frequencies with the results from the physico-chemical monitoring being periodically validated by the results of the biological monitoring

Determinant selection

The criteria for determinant selection are considered to reflect the probability to detect a substance. These criteria are:• ‘Detectability’, described as the ratio between the parameter and its LOD. Large numbers indicate ‘easily detectable’ and vice versa

• Degradability; a half quantitative criterion that describes whether a substance is refractory and shows conservative behaviour or whether t is rather easily degradable. Conservative substances need only limited sites while degradable substances need to be monitored in more locations or closer to the source.

Frequency of Operational Sampling

Monitoring Frequencies should provide a reliable assessment of the status of the relevant quality element.

The more frequent monitoring will mostly likely be necessary than surveillance monitoring in many cases.

The way data arising from traditional sampling programmes (e.g. regular monthly sampling) and from more targeted sampling, as might be used in operational monitoring, must be treated appropriately.

To confirm this statistical analysis can be used.

Protected Areas e.g. Drinking water abstraction points

Bodies of surface water which provide more than 100 m3 a day as drinking water an average shall bedesignated as monitoring sites

Such bodies shall be monitored for all priority substances discharged and all other substances discharged in significant quantities which could affect the status of the body of water and which are controlled under the provisions of the Drinking Water Directive.

Key Features of each BQE for RiversAspect/feature Benthic invertebrates Macrophytes Benthic Algae Fish Phytoplankton

Measured parameters indicative of QE

Composition, abundance diversity, and presence of sensitive taxa.

Composition and abundance , and presence of sensitive taxa

Composition and abundance, , and presence of sensitive taxa

Composition and abundance, sensitive species diversity, age structure,

Composition, abundance and planktonic blooms, and presence of sensitive taxa

Supportive/interpretative parameters measured or sampled at the same time

Morphology, physico-chemical parameters (e.g. Temp/DO, nutrients, pH etc), river flow, substrate/habitat sampled

Morphology, river flow, depth, transparency

Substrate/habitat sampled, morphology, nutrients (N, P, Si), TOC, pH, hydrological regime, light conditions

Substrate/habitat sampled, river size (depth/width), river flow, temp, oxygen

Chlorophyll a, flow, physico-chemical parameters (e.g. temp, DO, N, P, Si)

Pressures to which QE responds

Mainly developed to detect organic pollution or acidity, can be modified to detect full range of impacts.

Mainly used to detect eutrophication, river dynamics including hydropower effects.

Mainly used as an indicator of productivity. Can be used to detect eutrophication, acidification, river dynamics.

Can be used to detect habitat and morphological changes, acidification and eutrophication.

Used as indicator of productivity/eutrophication.

Mobility of QE Low, although unfavourable conditions may cause drift

Low. Generally fixed position.

Low High. Tendency to avoid undesirable conditions (e.g. low oxygen conditions).

High. Drifting with river water

Aspect/feature Benthic invertebrates Macrophytes Benthic Algae Fish Phytoplankton

Level and sources of variability of QE

High seasonal variation in community structure. Influenced by climatic events e.g. rainfall/flooding

High seasonal variation in community structure and abundance.

High seasonal variation in community structure. Limited by light and nutrient availability and available substrate for colonisation. Influenced by climatic events

High seasonal variation in community structure (e.g. spawning/migration) and abundance. High interannual variation due to age structure.

High inter and intra-seasonal variation in community structure and biomass. Influenced by climatic events, light, nutrient availability, stability and residence time

Presence in rivers Abundant Abundant if suitable habitat. Limited in fast flowing streams.

Abundant if suitable habitat. Limited in large, deep rivers with poor habitat

Abundant Generally low. May be abundant if conditions conducive to growth

Sampling methodology ISO 8265, 7828, 9391 (surber sampler, handnet, grab)

CEN –standard under development

CEN –standard under development

Depending on habitats – nets, electrofisher

Integrated sample (3-4m), depth sampler

Habitats sampled Riffle, pool (rocks/logs), edge (littoral), macrophytes,

Littoral, deposition areas (eg pools)

Benthic substrate/artificial substrate

All habitats Water column

Typical sampling frequency

6 monthly/Annual Annual/6 monthly Quarterly/6 monthly Annual Monthly/Quarterly

Key Features of each BQE for Rivers

Key Features of each physico-chemical element for Rivers

Investigative Monitoring

When a problem is indicated from the above monitoring schemes, it may be necessary to concentrate on monitoring water in a specific area.

This entails taking extra samples from additional locations and analysing specific parameters to obtain more detailed information.

An important aspect of investigative monitoring is to list the procedures for responding to pollution incidents.

Investigative Monitoring

An important type of investigative monitoring is part of Early Warning & Emergency Response Systems (EWER)

This consist of the procedures for responding to pollution incidents including monitoring this will be the subject of another presentation.

Thank you for your attention