On World Water Day in March 2022, we celebrated our groundwater. Groundwater is found underground in the cracks and spaces in soil, sand and rock. It can accumulate in aquifers and is used as a source of drinking water. It is estimated that 75% of people in Europe depend on groundwater for their tap/drinking water1.
Here we will look at the reasons why and how our groundwater resources are becoming contaminated and what can be done to stop this from happening.
Groundwater plays a huge and vital role in both our health and economic activity. Human activity can impact its quality as well as its quantity, as can climate change, endangering humanity’s supply of safe drinking water for the future.
Due to the ‘hidden’ nature of groundwater, restoration is even more difficult than for surface waters, mostly due to the ‘long memory’ of groundwater as pollution is very often irreversible.
Contamination occurs when pollutants infiltrate the ground or soil and leach into groundwater sources. The most common pollutants stem from agricultural practices such as the use of nitrates, coming from the excessive use of fertilisers and pesticides. Soils can also be contaminated by leaching landfills and hazardous chemicals emitted from industrial sites or as atmospheric deposition. Depending on the mobility, persistency and bioaccumulation of the substances, the soil characteristics and the depth of the aquifer, these substances can enter groundwater sources over time and cause long-lasting pollution of groundwater.
Once contaminated, it is difficult to return groundwater to its original clean state, and even when this is possible, it takes a long time as well as financial and human resources. Furthermore, the provision
of drinking water from a very contaminated source might not be possible, leading to a reduction of the available sources.
“due to the ‘long memory’ of groundwater , pollution is very often irreversible”
As stated in the Water Framework Directive (WFD), water suppliers must have access to adequate and reliable water sources that are protected from contamination so that the treatment to be applied
to drinking water is reduced over time; therefore, the sustainable protection of groundwater is essential.


The EU holds the key to achieving this. It is in the process of reviewing several pieces of important legislation in this area: the Groundwater Directive (GWD) and EQS Directive lists of pollutants, soil legislation, the Sustainable Use of Pesticides Directive (SUD), and the restriction of PFAS and other potentially harmful substances through the REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) Regulation.
The revision of the annexes (Pollutant Lists) of the 2006 Groundwater Directive and EQS Directive should lead to a legislative proposal in September 2022. The GWD sets standards for pesticides and nitrates in groundwater, and identifies other substances for Member States to consider setting thresholds.
Establishing ground rules
Drinking water and wastewater services have an essential mission: ensure the supply of high-quality drinking water and effectively treat wastewater, thus contributing to the protection of human health and the environment.
This is why, in the revision of the Pollutants Lists, we are calling for the implementation of the Precautionary Principle: the principle that preventive action should be taken and that environmental damage should, as a priority, be rectified at source, as well as the Polluter Pays Principle, as laid out in Article 191.2 of the Treaty on the Functioning of the EU.
The revision of the Pollutants Lists should fully align with the zero-pollution ambition enshrined in the Chemicals Strategy for Sustainability and the Zero Pollution Action Plan (ZPAP). Thus, groups of substances and mixtures should be regulated according to a hierarchy of pollutants based on criteria such as CMR (carcinogenic, mutagenic and reprotoxic chemicals), PMT (persistent, mobile and toxic), PBT (persistent, bioaccumulative, toxic) and EDC (endocrine-disrupting chemicals), and on the related ECHA work, giving priority to those pollutants (or their metabolites/degradation products) that are relevant for drinking water resources protection and that of ecosystems.
On the Priority Substances list under the EQS Directive, we welcome the intention to consider PFAS as a group of substances. We support a strict restriction. Concerning Annexes I and II of the GWD, we support the inclusion of the 10 PFAS and other substances (pharmaceuticals) identified by Member State authorities. In addition, we also favour the inclusion of the “Sum of 20 PFAS” and “total PFAS” parameters (as stated in the new Drinking Water Directive (DWD)) to ensure consistency.


We need to protect our groundwater resources. If, as a last resort, water service providers need to implement additional costly treatments in order to remove substances of emerging concern to fulfil legal requirements imposed by the DWD, the extra-treatment costs have to be covered according to the Polluter Pays Principle through various tools, including extended producer responsibility (EPR) schemes to keep water services affordable.
The right mix
Soil and water are intrinsically linked, and healthy soils help protect water resources in a sustainable way. Soils provide natural functions as they adsorb substances from water and contribute to percolation and groundwater recharge.
For this reason, the future European Soil Health Law should include concrete objectives to support the protection of drinking water resources, thereby improving groundwater quality. This requires – among others – reducing agricultural emissions from fertilisers and pesticides, remediating contaminated sites, addressing ‘at source’ diffuse soil contamination due to atmospheric deposition and/or waste disposed on land and taking preventative measures.
We also support the adequate integration and coordination of both soil and water management as well as measures that contribute to reducing nutrient losses. Soil must be used in a sustainable way so that its capacity to deliver its natural functions is not hampered. Contaminated sites must be identified, registered and remediated in line with the Polluter Pays Principle.
Using pesticides sustainably
We need to be clear: it is not a question of whether drinking water operators are capable of treating any type of raw water. The real question is, “do we as a society, and as individual citizens, prefer drinking water of a most natural composition or a highly treated and processed product with significant carbon emissions?”
The Farm2Fork (F2F) Strategy announced the evaluation of the Directive on the Sustainable Use of Pesticides (SUD). Pesticides are substances that prevent, destroy or control a harmful organism (a ‘pest’) or disease, or protect plants or plant products during production, storage and transport. They include herbicides, fungicides, insecticides, acaricides, rodenticides, growth regulators, repellents etc.
It is vital that we have enough food for all at a fair price. However, the same is true for water. Water suppliers need that water resources are protected to realise the right to water so that drinking water is safe as well as affordable.


According to the European Environmental Agency (EEA), one or more pesticides were detected above their effective threshold in up to 30% of all surface water (rivers, lakes) monitoring sites between 2013 and 20192.
Agriculture is considered the greatest contributor to pesticides in surface and groundwater used for the abstraction of drinking water, through application, runoffs or incorrect disposal. Pesticides, their metabolites and transformation products are more and more having a negative impact on the quality of drinking water resources, and drinking water operators have to increasingly resort to expensive and energy-intensive additional treatments, while consumers bear the costs.
The SUD is supported at EU level by two strategies: the Farm to Fork Strategy (F2F), is at the heart of the European Green Deal, aiming to make food systems fair, healthy and environmentally-friendly. It also has two pesticide reduction targets: a 50% reduction in the use and risk of chemical pesticides and a 50% reduction in the use of more hazardous pesticides.
The second is the ZPAP, which intends to achieve reduce pollution to levels that are no longer considered harmful to health and ecosystems, creating a toxic-free environment and cleaning the air, water and soil by 2050.
Member States have failed to deliver the adequate protection of drinking water sources. Water utilities have not witnessed a significant decline in the presence or in the concentration of pesticides in drinking water resources over the past decade. In certain regions, concentrations are even increasing.
“water utilities have not witnessed a significant decline in the presence of pesticides in drinking water resources over the past decade”
That is why EurEau fully supports the ambition of the F2F Strategy and the Commission’s proposed reduction goal for pesticide use of at least 50% by 2030.
We also stress the importance of drastically reducing the use of pesticides in drinking water catchment areas, in line with the provisions of the new DWD that oblige competent authorities to carry out a risk assessment and evaluate and initiate preventive measures, leaving mitigation measures as a tool of last resort. This is of particular importance for the protection of groundwater used for the abstraction of drinking water, because groundwater pollution lasts for a long time.
In order to be able to implement the DWD, water operators believe it is fundamental to enhance the availability, the granularity, the transparency, and the accessibility of the data on pesticides application up to the agricultural unit/field/crop, something that will be essential for carrying out the risk-based approach in terms of the drinking water resources and the abstraction of drinking water. The new rules on the use of pesticides must consider “sensitive areas” any protected areas under the WFD, including the safeguard zones established according to Article 7(3) of the WFD as modified by the implementation of the new DWD.


Adequately sized buffer zones must ensure effective protection according to the properties of the pesticides and the local conditions.
At the same time, we appreciate the intention to prioritise and widen the implementation of integrated pest management with adequate obligations for professional users.
If, despite all, these measures to protect drinking water resources fail and additional measures at the level of drinking water production become necessary to protect human health, then the Polluter Pays Principle should be applied consistently.
It is also fundamental to enforce the provision of the current Plant Protection Products Regulation that obliges Member States to review the authorisations for active substances of pesticides in case concentrations in water resources exceed the objectives set by the water legislation.
REACH-ing out for a full ban on PFAS
Per-and polyfluoroalkyl substances (PFAS) – or ‘forever chemicals’ – are a group of around 5,000 chemicals that are used to make fluoropolymer coatings and products that resist heat, oil, stains, grease, and water. These fluoropolymer coatings are found in a variety of products (food wrappers, umbrellas, frying pans, paint, some textiles and fire-fighting foam, to name a few) as their water-repelling properties and durability are very useful.
PFAS either are, or degrade to, very persistent chemicals that can accumulate in humans, animals and the environment and may cause adverse effects. They are widely present in the environment, in soil and in food.
PFAS can enter and contaminate groundwater resources either through sites where they are made, used, disposed of, spilt or through seepage.
Although a Europe-wide quantification of the different routes of human and environmental exposure is not complete, it is estimated that the contribution of PFAS accumulation in humans through food is in the range of 83-98%, and the contribution through drinking water in the range of 2-17%. More recently, inhalation has been identified as another important route.
It is not yet definitively known if all PFAS have a detrimental effect on our health and at which concentrations. Research is ongoing into this. While we are waiting for a definitive answer, it is better to be cautious – in line with the Precautionary Principle – and have a total ban on these chemicals.


First, some PFAS have been proven to be toxic, while for the rest, there are many unknowns regarding their impact on health and the environment. For some of these substances, the tolerable weekly intake has been reduced by several orders of magnitude. We cannot exclude that the same will happen with other PFAS.
Secondly, PFAS pose a problem for water operators precisely due to their very persistent and very mobile (vPvM) qualities.
In the absence of effective control-at-source measures, PFAS are released to the environment through multiple pathways and, locally, may reach drinking water resources, including groundwater resources. Due to their persistency, concentrations are likely to increase and drinking water suppliers will have to resort to costly extra treatment measures to comply with the limit values set in the 2020 DWD or national regulations.
The applicability of advanced (industrial) technologies to remove PFAS from our drinking water, based on physical separation or destruction techniques, is currently being investigated in pilot projects in laboratories. The results indicate that the large-scale removal of PFAS in water treatment plants will not be economically nor environmentally viable, while being technically challenging.
And there is a third reason to call for a rapid phase-out of all PFAS uses. The EU has so far failed to implement the Polluter Pays Principle enshrined in the TFEU and emphasised in the Chemicals Strategy for Sustainability and the ZPAP. The cost for extra water treatment or for the development of new, uncontaminated drinking water wells is not borne by those who sell PFAS, but by the water consumer.
The EU institutions have a golden opportunity to make a lasting impact on human health and environmental protection through the ZPAP. The ZPAP in its aim to achieve no pollution should go beyond a monitoring exercise and should take actions to reduce pollution at the source. Banning PFAS would be a major achievement.
The European Commission has begun work on a revision of the REACH Regulation. The REACH Regulation addresses the production and use of chemical substances, and their potential impacts on both human health and the environment.
There are many reasons why PFAS should be phased out, which can be done under REACH. Already today, we find a cocktail of different PFAS in many of our aquifers, and in varying concentrations. Depending on the local situation, drinking water suppliers may have to take expensive and resource intensive measure to guarantee the quality of our drinking water from both surface and groundwater. The REACH restriction initiated by five Member States must lead to zero PFAS emissions into the environment.
Act now
The time is now for the European Commission and Member States to do more to better protect our groundwater sources so that these can continue to be used as reliable and safe reservoirs for society’s drinking water needs even in light of climate change.


They can do this in a number of ways. Efficient and effective legislation and environmental awareness are needed to prevent deterioration and improve the resource quality of groundwater. The structures are already in place. We have tools across the EU that protect our water environment, such as the Control-at-Source, the Polluter Pays and the Precautionary Principles, that are set out in the EU treaties. These need to be finally implemented according to the aims of the European Green Deal and its flagship initiative – the zero pollution ambition. We see new times are dawning and we fully support this urgently needed interdepartmental strategy to protect our environment for generations to come.
References
1 https://ec.europa.eu/environment/water/water-framework/groundwater/resource.htm.
2 https://www.eea.europa.eu/highlights/new-indicator-on-pesticides-in