Mercury emissions from coal combustion driving poor status of EU freshwaters

A 2027 coal phaseout is needed if EU legal obligations on limits of toxic mercury in freshwater are to be met.

The atmospheric deposition of mercury predominately emitted by coal combustion plants is contributing to the failure of good chemical status of freshwater bodies in the European Union.

Member States have not taken sufficient action and risk breaching EU water law that necessitates the phaseout of mercury emissions, as explored in a new briefing from the European Environmental Bureau.

A toxic heavy metal

Mercury is a pollutant that is highly toxic to living organisms, including humans. The combustion of coal is the main source of mercury to air in the EU, representing around 60% of emissions.

Just 10 coal combustion plants found in Bulgaria, the Czech Republic, Germany (based on data for 2017) and Poland emitted 7.6 tonnes of mercury in 2019, more than twice that of the emissions of France, Greece and Spain combined.

Once emitted, mercury persists in the atmosphere and disperses widely, existing in different chemical forms. It can be converted into an especially toxic organic form called methylmercury via natural processes.

Mercury builds up in living organisms and becomes progressively more concentrated higher up the food chain via a process called bioaccumulation. This process represents the main risk of exposure for people: through the ingestion of food containing mercury.

There is no safe level of exposure to mercury and it is particularly dangerous for foetuses and young children, as exposure causes neurological damage, slowing brain development and negatively affecting cognitive abilities. The pollutant also affects the cardiovascular system, kidneys, liver and lungs.

Mercury on the water

The atmospheric deposition of mercury is the reason behind the failure of over 45,000 or 30% of water bodies in the EU to achieve good chemical status, as defined by the Water Framework Directive (WFD).

This Directive is the main EU legal instrument that set out to achieve the good status of all EU water bodies either by 2015, or by 2027 at the latest. Despite the adoption of the Directive 20 years ago, 40% of water bodies are in a bad chemical status due to excessive concentrations of what are known as Priority Hazard Substances.

Mercury is defined as one of these Priority Hazardous Substances, which means Member States are obligated to take measures to cease mercury emissions. Water protection authorities have so far not addressed mercury pollution in the River Basin Management Plans, the main tools used to implement the WFD.

While the remediation of mercury already emitted is costly, preventing the pollutant at its source by stopping the combustion of coal is much more affordable and effective.

Jeopardising the environment

Mercury emissions are also covered by another piece of binding EU legislation, namely the Industrial Emissions Directive, which aims to reduce harmful emissions from industry. This Directive mandates stricter permit conditions for emissions in cases where environmental standards are not met.

However, permit writers align their emission limits to the most lenient of standards set by the Directive, leading to the majority of cases remaining business as usual when it comes to mercury emissions. Meanwhile, derogations for setting less strict emissions values are allowed under the Directive in what are supposed to be limited and specific cases, but in reality Member States have used these derogations extensively.

“This piece of legislation looks to protect the environment as a whole, by preventing pollution at the source. So, when permits are granted, it must be in the spirit of those aims. But again and again, we see permits approved that totally contradict those aims of protection and directly jeopardise the environment. We need to start using the Industrial Emissions Directive as it was intended: to protect human health and the environment,” said Bellinda Bartolucci, a lawyer at environmental law charity ClientEarth.

Implementing the stricter emissions standards set out in the Industrial Emissions Directive, as well as those recommended by the guidance on coal combustion from the Minimata Convention, would cut the emission of mercury substantially – but coal combustion will still emit mercury even with the strictest standards applied.

Kicking coal for water by 2027?

To comply with the obligation to phase out mercury due to it being a Priority Hazardous Substance under the Water Framework Directive and to fulfil the Directive’s objective of achieving good chemical status of EU waters, Member States would need to cease coal combustion by the end of 2027 at the latest.

The upcoming review of EU law on mercury as part of the European Green Deal zero pollution ambition for a toxic-free environment presents an opportunity to further cut down on mercury pollution. Strict pollution control limits of other sources of mercury emissions would be required, such as for the production of cement, iron, steel and non-ferrous materials, alongside the prohibition of burning high mercury containing fuels.

The European Commission should also not approve any state aid to coal combustion plants with closure dates beyond 2027, as to do so would be funding the continuing emissions of mercury.

“Mercury is a key reason why European rivers and lakes are in poor chemical health. But instead of taking measures against the largest emitters, countries like Germany, Czech Republic and Bulgaria allow large coal plants to emit above EU standards, ignoring the fact they have a legal obligation to take every possible measure to restore Europe’s waters to good status by 2027,” said Sara Johansson, European Environmental Bureau Policy and Researcher for Industrial Production.

European countries were already under pressure to phase out coal by 2030 at the latest to be in line with the UN Paris Climate Agreement, but several will not meet the 2027 Water Framework Directive goal under their current plans.

Denmark, Finland, Germany, the Netherlands, Slovakia and Spain are aiming for phaseouts after 2027 but by 2030, while Bulgaria, Croatia and Romania have indicated phaseouts for post-2030. Discussions continue for the phaseouts of the Czech Republic and Slovenia, and Poland has stuck to its distant 2049 target.