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Ground-breaking research shows 99.9% microplastics are removed from UK drinking water

  • More than 99.9% of microplastics are removed from drinking water and waste water through water company treatment processes
  • Water industry calls for government, customers and businesses to do more to prevent plastic entering the water system in the first place

Pioneering water industry research has revealed that water treatment processes remove 99.9% of microplastic particles from sources of drinking water.

The research found that raw water (untreated water in the environment) contained on average 4.9 microplastics per litre while potable water (water that has gone through a treatment process) contained only 0.00011 microplastics per litre.

While our water treatment processes have been shown by the study to be very effective at removing microplastics from drinking water and treated wastewater returned to the environment, the water industry is calling on government and business to do more to prevent plastic entering the water environment and the sewer network in the first place.

Microplastics are present in our waterways and our wider environment due to the volume of plastics used in society today. They get into our water system both from direct and indirect sources – such as particles released from wear of car tyres on roads or microfibres released from synthetic clothes when washed – and from the breakdown of larger plastics such as litter washed into drains, and items such as sanitary products incorrectly flushed down toilets that subsequently break down into smaller particles. New measures are needed to control these causes of microplastic pollution at source.

The ambitious measures set out in the EU Single Use Plastics Directive represent a significant first step in reducing the quantity of plastic waste entering drainage systems and the environment, and must be implemented in full. Additionally, while the government’s intention to introduce an extended producer responsibility system for packaging in 2023 is welcome, stronger incentives and penalties must also be put in place to encourage producers to avoid harmful formulations in other products (such as tyres and clothes), and to take responsibility for preventing pollution and cleaning up the environment.

The research, carried out by the Centre for Ecology & Hydrology, is the most robust study of its kind to date. It was commissioned by UK Water Industry Research (UKWIR) to create a better understanding of microplastics in the water system. The research comes after a recent report from the World Health Organisation said there was no current evidence of any risk to human health from the presence of microplastics in drinking-water but called for more research into the potential impact.

The water industry is planning more research to better understand microplastics and their impact on its operations and activities. The findings and recommendations from this research will be used to inform discussions between the water industry, regulators and stakeholders to define and develop the next research steps.

English water companies are committed to tackling plastic pollution at source, aiming to prevent the equivalent of 4 billion plastic bottles ending up as waste by 2030. In addition, the sector will end the use of avoidable single-use plastics in our businesses and help the public make a real difference by providing them access to tens of thousands of free drinking water refill facilities through our partnership with the Refill campaign

Steve Kaye, Chief Executive, UKWIR said:

“We’re pleased to publish this important piece of UKWIR research and share the findings with everyone who, like ourselves, is seeking to further the science around the source, fate and impact of microplastics.

“As our study shows, one of our key objectives was to ensure the sampling and analytical techniques used were robust enough to produce credible results. We’re confident the Centre for Ecology and Hydrology, who carried out the research, have achieved this. It’s good news that the research demonstrates the water industry’s treatment processes are performing well in removing microplastics, something they were not designed to do but are achieving with significant success.

“As ever, with important pieces of research, it has raised further questions which require more study by ourselves and others. We’ll now work with the water industry’s regulators and partners to prioritise the next steps.

 Michael Roberts, Chief Executive, Water UK said:

 “This important research underlines the effectiveness of water treatment in the UK in removing microplastics and other pollutants from our water supply. It’s thanks to these robust processes that the we all enjoy world class water whenever we turn on our taps.

 “However, while the vast majority of microplastics are removed in the treatment process, we aren’t complacent and therefore will support UKWIR in undertaking further research to understand the true nature and impact of this hidden problem.

“Action from government, industry and the public remains critical to prevent these microplastics entering our water system and wider environment in the first place. Tackling our over reliance on plastics and improving end of life collection will be the only way to effectively address any risks from such pollutants.”


For more information please contact the Water UK communications team on 020 7344 1805 or


UKWIR is the research body for the UK and Irish Water industry. They facilitate, manage & deliver a strategic programme of research projects to address the key ‘one voice’ challenges facing the water industry.

Water UK

Water UK is the trade body representing all of the major water and wastewater companies in the UK. Our members provide drinking water to nearly 64 million people every day. The water industry has set out ambitious plans to prevent the equivalent of 4 billion plastic bottles ending up as waste as well as improving 8,000 km of rivers and waterways over the next few years.

Centre for Ecology & Hydrology

The Centre for Ecology & Hydrology (CEH) is the UK’s centre for excellence in environmental science across air, land and water. CEH is a Natural Environment Research Council (NERC) research institute, part of UK Research and Innovation (UKRI).