Science Week

The Role of the Environmental Protection Agency in Protecting Our Waters

Ripples in a river

Published in Blog - 8 min read - Sep 21, 2026

Ripples in a river

Article by the Environmental Protection Agency (EPA), whose work helps to protect, improve and restore our environment through regulation, scientific knowledge and working with others.

The purpose of the Environmental Protection Agency (EPA) is to protect, improve and restore our environment through regulation, scientific knowledge and working with others. Our vision is that we live sustainably in a healthy environment that is valued and protected by all. 

In the water area, the EPA’s responsibilities include: 

  • monitoring, assessing and reporting on the quality of rivers, lakes, transitional and coastal waters, bathing waters and groundwaters, and measurement of water levels and river flows 
  • monitoring and assessing the impact of human activities and pressures 
  • regulation of wastewater, industrial and waste activities and oversight of local authority performance of their statutory environmental functions 
  • reporting to the Commission under a range of directives including the Water Framework Directive, Nitrates Directive and the Bathing Water Directive and 
  • co-ordination and funding of environmental research activity to identify pressures, inform policy and provide solutions.  

Given the EPA’s role in protecting Ireland’s waters, we are delighted to partner with Research Ireland for this year’s Science Week.  

Did you know that the EPA is also responsible for monitoring levels of radioactivity in seawater around Ireland? 

There are natural and human-made sources of radioactivity in the environment, including the marine environment. 

Naturally occurring radioactivity has been present in the environment including our seas since the earth was formed. Sources of human-made radioactivity include nuclear reprocessing plant discharges, nuclear weapons fallout and nuclear accidents. 

The EPA has a marine monitoring programme in place to assess levels of radioactivity in seawater, seaweed, fish and shellfish from around Ireland’s coastline.  

The focus of this monitoring programme is on human-made sources of radioactivity and there is less information available on naturally occurring radioactivity in Ireland’s marine environment.   

The Radioactivity in the Irish Coastal Environment (RICE) project funded by the EPA was undertaken to provide an updated assessment of radioactivity in the Irish coastal environment. A key focus of this project was to understand the baseline levels of naturally occurring radionuclides (unstable atoms that emit radiation) and the current levels of human-made radionuclides.  

Levels of naturally occurring and human-made radionuclides were determined in seaweeds, sediments, oysters and salmon. The analysis used advanced laboratory processes such as high-resolution gamma spectrometry, radiochemical techniques and alpha spectrometry.  

Here’s what the assessment found: 

  • Across all samples, naturally occurring radionuclides were found at higher levels than those of human-made radionuclides.  
  • While human-made radionuclides were detected, particularly along the north-east coast of Ireland as a result of low-level liquid radioactive waste discharged from the Sellafield nuclear fuel reprocessing site on the north-west coast of England, their activity concentrations are generally significantly lower than those of naturally occurring radionuclides.  
  • Comparison with historical surveys and monitoring data confirms a substantial reduction in human-made radionuclide concentrations since the 1980s, reflecting reduced discharges from Sellafield, the natural decay of radioactive material over time and environmental redistribution.  
  • The study also looked at the radiation dose people may receive from eating seaweeds, oysters and salmon. The principal contributor in this case is the naturally occurring radionuclide polonium-210, while human-made radionuclides provided a negligible contribution. Estimated ingestion doses associated with the consumption of these seafoods are low and are not considered to be of radiological concern based on current dietary habits.  

Overall, the RICE project provided a comprehensive assessment of radioactivity in the Irish coastal environment, established robust national baseline data for naturally occurring radionuclides, confirmed the continued decline of human-made radionuclides associated with historical discharges, and demonstrated that current levels of radioactivity in Irish coastal waters are dominated by natural sources.  

The good news is that radioactivity in the Irish marine environment does not pose a threat to human or marine life, but it is important that the EPA keeps monitoring the levels to ensure this remains the case.  

For more information, visit epa.ie

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