5. Improving protection against chemical risks in water

5.1.         Introduction

Earlier chapters discussed approaches to tackle the significant concern that we are failing to adequately protect aquatic ecosystems from mixtures of low concentrations of chemicals, and reviewed information available for established water pollutants. Once released into the aquatic environment, persistent, harmful chemicals are very difficult to control and may have long-lasting effects. We need effective ways to protect our water resources, so as to ensure their long term sustainability.

Two major challenges confront our understanding of chemicals in surface waters across Europe. The first is that, despite significant effort, we struggle to show that at the European level there have been improvements in the environment resulting from increased controls of the most well-known pollutants. The second is that chemical status under the WFD reflects scientific understanding that is at least 20 years old.

Headline chemical status is driven by the “one out all out” approach of the WFD, where the status reflects that of the worst component. For chemicals, the pass/fail nature of the EQS means that the failure of one priority substance or one RBSP will lead to the water body failing to achieve good status. Although it is possible to see improvements in individual priority substances (EEA, 2018a), the revision of EQS and addition of new priority substances to reflect better understanding of chemical risks represents recurrent new challenges to achieving good chemical status. This difficulty is more than a “communications issue”. Maintaining political support and resources towards improved environmental protection is difficult at every level  when little, no, or even negative progress is made.

There is a need to be able to communicate about improvements made according to the standards when they were set. Equally, the WFD needs to reflect robust, new scientific understanding which identifies new risks. This chapter reflects on the findings of earlier chapters and proposes some possible ways forward.

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5.2.         Data collection on chemicals in water at EU level

Significant effort goes into reporting into the European system and then in making that information available. In the light of Peter Drucker’s observation, “if you can’t measure it, you can’t change it”, we reviewed what was available for key chemical pollutants.

5.2.1.     Data on chemical status and priority substances
Monitoring obligations need to balance costs of resources to undertake them, with the value of the knowledge gained and application of that knowledge. Collecting data which have no application is not only wasted effort, it may mean that an opportunity is missed to gather information which would be used to inform measures.

What should be a priority substance? A working basis for a “European level pollutant” is provided by the prioritisation process, which considers a substance to be of European concern if it exceeds proposed EQS in 4 or more Member States (JRC, 2016). Following reporting of the second River Basin Management Plans, the continuing relevance of a priority substance can be considered. (table 5.1).

Table 5.1: Priority substances which exceed EQS in less than 15 (out of 111 105) surface water bodies and 4 or fewer Member States

Source: https://tableau.discomap.eea.europa.eu/t/Wateronline/views/WISE_SOW_PrioritySubstance/SWB_SWPrioritySubstance_Europe?:embed=y&:display_count=no&:showVizHome=no (29 Aug 2018)

Preliminary results based on WISE-SoW database) including data from 25 Member States (EU28 except Greece, Ireland and Lithuania).

The very low numbers of water bodies failing for these substances suggest that, assuming monitoring and reporting are accurate, measures have been effective in preventing the entry of these chemicals into surface waters. This is a success for European water and chemicals policies.

With such low numbers of water bodies failing to achieve good status for these substances, they may be candidates for delisting as priority substances, freeing up resources for monitoring of substances now presenting more of a risk to the quality of European waters.

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It is also possible to review River Basin Specific Pollutants to identify those which might have European wide relevance (table 5.2). RBSPs most often exceeding their EQSs are shown, with the range in EQS values used (derived from Member States RBMP reporting).

Table 5.2 Selected River Basin Specific Pollutants with largest numbers of countries reporting failures; Comparison of minimum and maximum national standards for annual average EQS.

Note: Data from RBMP reporting differ from those reported by Irmer et.al. (2014) which were derived from voluntary reporting.

– 1 country had standards for both free and total cyanide, hence 8 countries reported in table 2.1.
Source https://tableau.discomap.eea.europa.eu/t/Wateronline/views/WISE_SOW_FailingRBSP/SWB_FailingRBSP_Europe?:embed=y&:display_count=no&:showVizHome=no  (30 Aug 2018)

Decisions on what substances are proposed as priority substances are made through the collaborative process under the WFD, prior to a Commission proposal subject to the co-decision process. It is currently unclear when the next revision to the list of priority substances may be made.

Guidelines for EQS derivation are set in the technical guidance document for environmental quality standards (EC, 2011b). Although such documents should promote coherence and harmonisation, EQS values can differ by up to 10 000 times for the same substance (e.g. phenol, glyphosate) (Irmer, et al, 2014).

As well as variation in values of EQS, there can be significant differences in numbers of RBSPs between Member States – between 1-136 RBSPs were reported as causing failure in the 2nd RBMPs[1]. This has an influence on the likelihood of an RBSP failing to meet an EQS, and so the likelihood of a water body being able to achieve good ecological status. More RBSPs make it more likely that a water body may not meet the EQS.

Looking forward, it would seem that improving consistency (or harmonising) RBSP EQS values would improve comparability between river basin districts. It would not address differing numbers of substances for which standards are set, and, given the variation across Europe of substances meeting the RBSP definition, it seems difficult to overcome that issue. Consideration should be given to including all chemicals information in one place, e.g. chemical status, reflecting actual water management, if other ways are found to better integrate chemical and ecological status.

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5.2.2.     Emissions to water
Reporting known or estimated chemical emissions is a way to gather information on trends over time, without knowing what impact those might have. Unfortunately, emissions data on priority substances as reported for the WFD, E-PRTR and WISE-SoE are only partially informative. The WFD dataset is difficult to interpret, with apparent errors, inconsistencies and missing river basin districts. 

Lack of comparable information at EU level on diffuse sources of pollution to water represents a potentially significant gap (Roovaart et al, 2013a and b).

Given these significant concerns, what can we see in the data? 

Table 3.2 provided an overview of the number of Member States reporting of emissions in 2010 for the different source groups: industry, UWWTPs and diffuse sources.

The metals cadmium, lead, mercury and nickel were widely reported, but even for these long-regulated substances are there difficulties with the data reporting. While a range of diffuse sources were reported for metals, different approaches in calculation between the countries render those data incomparable.

For another set of pollutants, about half of the countries reported on a regular basis (some PAHs, 4-Nonylphenol, DEHP). Although this allows for some overview at European level, there were difficulties with the data from different reporting streams (E-PRTR, WFD, WISE-SoE), making interpretation of trend difficult.

For a number of pollutants, only a few Member States report loads (TBT, Brominated diphenylethers, Isoproturon, hexachlorocyclohexane). Therefore, no useful overview exists for these pollutants at EU level.

Diffuse sources of pollution have been reported by only a few countries, even though – where they are reported – they seem to constitute a large proportion of diffuse sources for almost all priority substances (Roovaart et al, 2017). This represents a significant data gap.

Ways forward :

Currently, data on emissions are required under EU legislation for both EPRTR and WFD, and are voluntarily reported under WISE SoE. Improving emissions data so that they are collected under consistent and comparable approaches would provide clear information on the direction of travel for chemical pressures. This could be especially helpful for substances where the surface water chemical status assessed under WFD is driven by historic rather than current emissions. Streamlining reporting, so that robust data collected for one obligation would satisfy the European emissions reporting requirement, could offer a way to address this issue.

As point sources of pollution are better controlled, so the relative significance of diffuse sources increases. Our lack of knowledge about diffuse emissions represents an important information gap. Improvement in the monitoring and reporting of diffuse sources is needed, to ensure that pressures are correctly understood and measures can be appropriately targeted.

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5.3.         Conclusions on assessing ecological impacts from chemical pollution

The chemical status of surface waters, reported under the WFD, provides an assessment of a very limited number of harmful chemicals in water bodies comparable across Europe. Much more detailed information on chemical contamination can be available at a more local scale. Through scientific efforts like the application of novel methods of sampling and chemical enrichment (Schulze et al. 2017), the detection of several hundred organic chemicals in a single freshwater sample is becoming more common.

Currently, there is no established link between the assessment of chemical status and ecological status of surface water bodies. This is in contrast to the real situation where organisms may be living in polluted water, possibly impacted by multiple pressures. Improvements in our understanding as to how chemical mixtures can adversely impact organisms may be used to improve our understanding of the interlinkage between ecological status and chemical status. Application of the precautionary principle means this should include consideration of chemical mixtures, which can act along similar pathways in the organism. However, potential consequences of the presence of multiple chemicals is not reflected in current lists of priority substances and RBSPs.

More generic solutions are needed to protect water from contamination by chemicals. Approaches which regulate concentrations in water on a substance-by-substance approach will not cope with large numbers of substances present at apparently low concentrations but which might, in combination, have ecological effects. Effects-based approaches offer a way to combine existing information on the presence and abundance of species in ecological monitoring, while improving our understanding of the links between chemical and ecological information. The flexible approach of the WFD would allow Member States to use effects-based methods in a complementary way, alongside routine monitoring in water management. The major obstacles to the use of such tools seem to be the mis-alignment with chemicals source control approach, aimed at single substances, and the lack of legal obligation. In the absence of legal requirement, one way to demonstrate the value would be to collect case studies where effect-based information has been used in a regulatory context for surface waters. Another option is for effects-based methods to be used as part of ecological status assessment.

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5.4.         Conclusions on the effectiveness of source control legislation

Reported emission data do not allow quantitative conclusions about the effectiveness of source control measures taken in the past. The data are not sufficiently reliable and the time series are not long enough for analysis. However, emission loads should have decreased, driven by the implementation of the directives on Dangerous Substances (1976), Urban Waste Water (1991) and Industrial Emissions (2010). Additionally, chemicals are now widely regulated and environmental concerns reflected in risk and hazard assessments (chapter 1.3).

Over recent decades, reductions in emissions from industry have led to significant sources now being from domestic use (Gardner et al, 2014). Despite much tighter regulation, pesticide use in agriculture can still cause contamination.  Events such as heavy rainfall can overload drainage systems and cause surges in the pollutant load into surface waters.

We rely on urban waste water treatment to reduce concentrations of many pollutants in water, but they may not meet sufficiently low concentration of micro-pollutants such as pharmaceuticals, ingredients of household chemicals, chemicals used in small businesses or industries, or pesticides. Investigations into more advanced waste water treatment techniques, for the elimination of micro-pollutants via a fourth treatment stage, are being tested in several countries. Such techniques cost about 10 to 15 EURO cents per m³ in big treatment plants, but they are not yet applied on a regular basis (UBA, 2018).

Table 5.1 showed examples of substances for which measures to prevent water pollution seem to have been effective. Sometimes this involved totally banning the use of a substance; less drastic measures may be to restrict uses where losses to water might occur, either through more careful use of the substance (such as in good practice for pesticide application) or banning its use in certain applications because such measures are not possible.

In this report, the focus has been on priority substances continuing to present a risk to Europe’s surface waters. Table 5.3 summarises the current situation and considers what more could be done to improve environmental protection.  

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Table 5.3 – Effectiveness of controls to prevent chemicals reaching aquatic environment from point sources

Note – Information on diffuse sources is mostly poor, so excluded from this table.  

1 - see Table 3.2

2 – table 3.1 based on 111 105 water bodies and number of water bodies failing for substance (Many = over 10 000; Medium = over 1 000; Low = over 100)

3 – Historic = use before 1940

4 – International restrictions as POPS

5 – regulatory approval for isoproturon expired in 2017, so data reflect the period where its use was still permitted

Moving beyond the well-established pollutants represented by priority substances, we need to implement methods which effectively assess the risk presented by mixtures in the aquatic environment. Longer term sustainability can be provided by the development of alternative approaches which deliver the desired function currently provided by harmful chemicals. Developing a circular economy is part of this process.

[1] https://tableau.discomap.eea.europa.eu/t/Wateronline/views/WISE_SOW_FailingRBSP/SWB_FailingRBSP?iframeSizedToWindow=true&:embed=y&:showAppBanner=false&:display_count=no&:showVizHome=no

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