The Environmental Protection Agency has said that overall water quality in Ireland's rivers, lakes and estuaries is getting worse after a period of relative stability and improvement.
In its Water Quality in Ireland report, the EPA found that the quality of almost half of river sources in Ireland is unsatisfactory and the number of pristine waters has fallen to an all time low.
The report assessed the ecological health of rivers, lakes, canals, groundwaters, estuaries and coastal waters.
Over 2,700 surface water bodies and more than 500 groundwater bodies were examined over a five-year period.
Just over half (52.8%) of all surface water bodies were found to be in satisfactory ecological health.
That is a 4.4% deterioration in overall surface water quality since 2015.
The deterioration has been driven mostly by increased nitrogen runoff from agricultural lands and phosphorus runoff from urban wastewater sources.
The EPA said the number of high status river water bodies has now fallen by a third in less than ten years.
The report says Ireland now has only 20 pristine river water bodies - less than 1% of all the river sections examined - which is a record low and compares with 500 pristine river sections in the 1980s.
The number of fish kills increased to 40 in 2018 after a historic low of 14 in 2017.
The number of seriously polluted bad status rivers has increased to nine from a low of six over the past three years.
EPA Director Matt Crowe said water quality in Ireland is now getting worse after a period of stability.
Minister for Housing, Planning and Local Government Eoghan Murphy said it is more important than ever that all sectors now engage in this increasingly urgent situation and reduce their impact on water quality.
Since 2013, nitrogen emissions to water have increased as both cattle numbers and fertiliser use have increased.
Nitrogen emissions to water are a particular concern in the south and southeast of the country where losses to the marine environment are elevated and increasing, and the relatively freely draining soils are very susceptible to nitrogen leaching from agriculture.
The EPA said nitrogen loss reduction measures need to be targeted in these areas, for example by improving nutrient use efficiencies and reducing the use of chemical fertilisers.
Phosphorus concentrations are elevated in various parts of the country including parts of the northwest, northeast, east coast, southeast and south of the Shannon Estuary.
Phosphorus losses come primarily from waste water discharges and from runoff losses from agriculture on poorly draining soils.
The increase in human population since 2013 has resulted in an increase in waste water to be treated.
Works are ongoing by Irish Water to improve the level of treatment nationally, however further work is required to reduce the impact of waste water discharges on our water quality.
Main Findings of the EPA Report:
Overall Surface Water and Groundwater Status
- 52.8% of surface waters (rivers, lakes, transitional, coastal waters) are in good or high ecological status and the remaining 47.2% are in moderate, poor or bad ecological status.
- Overall there has been a 4.4% net decline (117 water bodies) in the quality of surface water bodies since 2010-2015.
- 92% of groundwater bodies are in good chemical and quantitative status which reflects a 1% improvement since the last period of assessment.
- 75% of monitored surface waters are in good chemical status. When ubiquitous priority substances are omitted, the percentage in good chemical status increases to 99% of surface waters.
- 53% of river water bodies are in good or high ecological status and the remaining 47% are in moderate, poor or bad ecological status.
- Overall there has been a 5.5% net decline (128 water bodies) in the quality of river water bodies.
- The number of high status river water bodies has dropped by nearly a third (91 water bodies) since the baseline assessment in 2007-2009.
- The dramatic loss of high quality biological sites (Q5 and Q4-5) seen since the late 1980s shows no sign of recovery. The number of remaining Q5 highest biological quality sites is now at an all-time low of just 20.
- The number of poor status river water bodies has increased by a third (110 water bodies) since the first assessment in 2007-2009.
- The number of seriously polluted bad status river water bodies has increased to nine having reached a low of six water bodies in the last assessment 2010-2015.
- Over a third (35.8%) of monitored river sites failed to meet the environmental quality standard for phosphorus.
- At least a quarter of river sites had increasing nutrient concentrations between 2013-2018.
- 50.5% of lake water bodies are in good or high ecological status; the remaining 49.5% are in moderate, poor or bad ecological status.
- There has been a 4.3% improvement in the number of lake water bodies in good or high ecological status since the last assessment in 2010-2015, but overall lake status has remained stable since the first assessment in 2007-2009.
- Almost a third (29%) of lakes failed to meet the environmental quality standard for total phosphorus.
- Over a quarter (28.8%) of lakes analysed had increasing trends in total phosphorus concentration.
- There has been little change in the quality of our canals since the last assessment; 13 of the 15 water bodies (87%) assessed are in good ecological potential.
Transitional and coastal waters
- 80% of coastal water bodies are in good or high ecological status, the highest for any surface water category.
- Transitional water bodies are the worst performing water category with only 38% in good or high ecological status and the remaining 62% in moderate, poor or bad status.
- Almost a quarter (23.3%) of estuaries and coastal waters failed the assessment criteria for dissolved inorganic nitrogen.
- After many years of reductions, loadings of phosphorus and nitrogen to the marine environment have started to increase. The average total nitrogen and total phosphorus loads have increased by 8,806 tonnes (16%) and 329 tonnes (31%) respectively, since a low in 2012-2014.
- 92% of groundwater bodies (474 out of 514) are in good chemical and quantitative status.
- 38 groundwater bodies (7.4%) are in poor chemical status and two groundwater bodies (0.4%) failed to meet the quantitative status objective.
- 97% of groundwater monitoring locations had an average nitrate concentration below the threshold value.