Only 53% of Irish surface water bodies have satisfactory water quality, showing a considerable deterioration in water quality, according to a new report from the Environmental Protection Agency (EPA) – with an increase in nitrogen (N) run-off from agriculture seen as a key factor in this.

The EPA published the Water Quality in Ireland Report for the period 2013-2018 today, Tuesday, December 10.

The key findings showed that 92% of groundwater bodies, 80% of coastal waters, 53% of rivers, 50% of lakes and 38% of estuaries were found to be of satisfactory quality.

Since the last full assessment, river water quality has got worse, with a net decline of 5.5% (128 water bodies) in the status of river water bodies.

According to the report: “Since 2013, N emissions to water have increased as both cattle numbers and fertiliser use have increased.

“N emissions to water are a particular concern in the south and south-east of the country where losses to the marine environment are elevated and increasing, and the relatively freely draining soils are very susceptible to N leaching from agriculture,” the report said.

N loss reduction measures need to be targeted in these areas, for example by improving nutrient use efficiencies and reducing the use of chemical fertilisers.

Waste water was highlighted as another key contributor – with increases in this down to increases in the Irish population, according to the EPA.

It was also found that the loss of the pristine (“best of the best”) river water bodies is continuing, with just 20 pristine river sites now left – down from over 500 sites in the late 1980s.

Meanwhile, the number of seriously polluted river water bodies (the “worst of the worst”) has started to rise – from six to nine – after many years of an improving trend.

The number of fish kills increased to 40 in 2018 after a historic low of 14 in 2017. It is likely that the hot summer and low flow conditions in 2018 had an impact on this.

Commenting on the assessment, EPA director Matt Crowe said: “Ireland has made commitments to protect and improve water quality, under the Water Framework Directive and the National River Basin Management Plan 2018-2021.

“However, the findings of this report indicate that water quality is getting worse after a period of relative stability and improvement.

“The main significant pressures impacting water quality in Ireland include agriculture, wastewater discharges, impacts to the physical habitat conditions including excess sediment (hydromorphology), and pressures from forestry activities.

Of particular concern in the most recent assessment is the increase in nutrients – N and phosphorus (P) – finding their way into our water bodies. Agriculture and waste water are the main sources of nutrients.

“Over a quarter of river sites monitored have increasing nutrient levels and nutrient loads to the marine environment have also increased,” Crowe said.

Mary Gurrie, water programme manager, added: “The overall increase in nutrient concentrations is a worrying development for our water quality.

“These excess nutrients come from human activities, predominantly our farms and waste water.

We need to address the sources and the pathways by which these nutrients make their way into our rivers and lakes. Good water quality is essential for our health and well-being.

“The National River Basin Management Plan sets out a programme of measures to protect and improve water quality. It is essential that the measures required are implemented in order to avoid further deterioration and achieve the good water quality which people expect,” Gurrie concluded.