Water Framework Directive Chemical Assessments In Wales…..

In the latest round of Water Framework Directive (WFD) assessments in 2021, 40% of Wales’s waterbodies (WBs) achieved at least good overall status. This rises to 44% when looking just at Welsh rivers and for chemical assessment, surface waterbodies achieved a 94% success rate for good status.

For a waterbody to achieve good overall status under WFD, it must be both good for ecological and chemical status – the ‘one out, all out’ rule. This is confirmed in Natural Resources Wales’s (NRW) “River Basin Management Plan Overview Annex Wales December 2022” .

However, Afonydd Cymru has concerns about the way chemical assessments for WFD are being carried out in Wales. We believe that differences in the way chemicals are being assessed are also resulting in differences in reporting of the state of rivers (and the wider environment) in Wales, in comparison with England, where no waterbodies achieved good overall status. 

Please use the sections below to find out more about the assessment of chemicals in Welsh rivers.


WFD Chemical Status in Wales

In addition to ecological assessments, WFD requires assessment of certain chemicals that may be harmful to humans and the aquatic environment. Waterbodies that meet chemical standards set out in the legislation are classed as ‘Good’. Those waterbodies where the level of chemicals exceed the standards are classed as ‘Fail’.

According to the 2021 WFD chemical classification in Wales, ‘only’ 48 waterbodies are ‘moderate’ in Wales, the rest being ‘High’ or in other words, a “pass” for chemical status classification.

However, 455 waterbodies (out of the total of 714) were not assessed by NRW for “Priority Hazardous Substances” and 452 were not assessed for “Priority Substances”. Despite this, all were still classified as ‘High’ status (in the absence of monitored data).

NRW have confirmed to Afonydd Cymru that….
“….any unmonitored parameter would not cause a failure by default and would be in theory be equivalent to a pass in relation to the impact on the overall classification.”

“We did extensive monitoring and risk assessment aided by expert judgement in the earlier cycles of WFD so that our current monitoring covers the combination of sites and substances to reflect the risk on the ground to the best of our abilities.”

In their protocol for assuming good status, NRW are following the UK Technical Advisory Group (UKTAG) on the WFD’s recommendations which are:
“……where there is no evidence from monitoring or risk assessments to the contrary; the status of a water body should be classed as being at high ecological status and good chemical status. The confidence in such classifications will depend on the quality of the information on pressures and the reliability of the methods of risk analysis.”

Further Information:

State of the water environment indicator B3: supporting evidence
Updated 22 May 2023

WFD Chemical Status in England

In England, the Environment Agency’s (EA) approach was based on a risk assessment methodology similar to the one currently used by NRW in Wales.

However, in contrast to Wales, the EA followed the following requirements of UKTAG:

“UKTAG recommends that the most up to date risk analysis results, supplemented by the most up-to-date results coming through from work on classification, should be used to design the programmes of measures.”

“UKTAG also recommends that the data collected for classification is used to help identify deterioration of status and long-term changes likely to lead to deterioration of status.”

“The process of classification involves making estimates of status mainly from the results of risk-based programmes of monitoring and assessment that are targeted according to the identified risks to water bodies. Sometimes monitoring data are used directly, as, for example, in comparing measurements of the average concentrations of chemical with an environmental quality standard. In other cases monitoring data are used with other information to estimate status using modelling techniques.

Estimates of the status of the water environment will improve over time. More data will accumulate, more advanced scientific techniques for collecting and interpreting data will be developed and the environmental standards used in assessing status may need to be updated to reflect the latest research. As a result, the status of some water bodies will be re-classed as better, or worse, than previously estimated. This may include some water bodies previously estimated to be high status or good status.”

In the latest assessments, the EA introduced a wider programme of monitoring on which to make the WFD chemical assessment. This resulted in 0% surface water bodies meeting the criteria for achieving good chemical status in 2019, compared to a 97% pass in 2016.

These widespread failures are mainly due to four groups of chemicals: polybrominated diphenyl ethers (PBDEs – a group of brominated flame retardants); Mercury; certain polycyclic aromatic hydrocarbons (PAHs) and perfluorooctane sulfonate (PFOS) a group of per-and polyfluoroalkyl substances (PFAS).
In Wales, these four chemicals were monitored only in a small number of waterbodies under regulatory WFD monitoring: PFOS: 4, PAH: 16, PBDEs: 4, Mercury: 0. This was less than 2% of the total waterbodies in Wales.

These chemicals are ubiquitous, persistent in the environment for a long time, accumulative in organisms, and are toxic. Chemicals such as PBDEs have widespread uses and are global pollutants. If they are in English rivers, it is highly likely that they are present in Welsh rivers.


Further Information:

UKTAG Recommendations on Surface Water Classification Schemes for the Purposes of the Water Framework Directive – 2007

Passive Sampling Programme

NRW have implemented a passive sampling programme as presented at Wales Water Forum in 2023, (of which Afonydd Cymru is a stakeholder). This programme employs passive samplers over a 2-6 week period (thus it is more robust than typical spot sampling undertaken in WFD) across a rolling programme of sites. Between 2018 and 2022, a total of 789 samples have been undertaken with over 2,500 separate parameters measured.

The passive sampling programme has identified a range of compounds at >80% of the locations sampled across Wales. A wide range of compounds have been detected, including pesticides, insecticides, pharmaceuticals and PAHs. Breaches were found greater than PNEC (Predicted No-Effect Concentration) at more than 90% of the sites.

This sampling operates as an additional monitoring programme to the WFD assessment, yet the early results did not seem to modify risk assessments in the 2021 WFD classification.

Specific Pollutants

Specific chemical pollutants fall under ecological status classification. According to UKTAG, for good ecological status, the Environmental Quality Standard (EQS) for specific pollutants must not be exceeded. 401 waterbodies in Wales were not assessed for specific pollutants, with 211 of those achieving ‘good’ ecological status. Again, this would therefore suggest that with monitoring of the standard we would expect the outcomes for WFD classification in Wales may be very different to that currently reported.

Additionally, in 2023, the Royal Society for Chemistry reported on the impact of PFAS in rivers in England and Wales. This highlighted further rising concern on chemicals in rivers and additional data which should inform WFD risk assessments.

Further Information:

“Cleaning up UK drinking water” Royal Society for Chemistry 

Afonydd Cymru’s concerns are:

  • The application of UKTAG guidance has potentially been interpreted differently in England to Wales.
  • The passive sampling programme provides data which indicates a wide range of chemicals at levels above safe thresholds. This suggests that the interpretation by waterbody in WFD assessments should be updated to reflect a wider chemical failure than is currently reported. This would likely lead to a decline in chemical and overall WFD classification status in Wales.
  • We do not believe, based upon the differences in monitoring and sampling in Wales, that comparisons can be made between WFD classification between England and Wales. We are concerned that a number of organisations in Wales generally make these comparisons, indicating that Wales’s status is much better than England’s. We feel this is a reflection on the monitoring and reporting, as opposed to any measurable environmental improvement.