Freshwater - State and impacts (Ireland)
State and Impacts
Elevated nitrate concentration in groundwater is an issue, particularly in the southeast and south of the country. It may contribute to eutrophication of surface waters and affect drinking waters. Diffuse agricultural pollution is considered the most significant source.Elevated groundwater phosphate concentrations, particularly in karst limestone areas such as Galway, Mayo and Roscommon, may be contributing to eutrophication in rivers and lakes.
Forty-nine percent of river water bodies are classified as having good or better ecological status, i.e. satisfactory, based on the WFD Interim Biological Classification for river water quality in 2008. 28 per cent of river water bodies are classified as having moderate, 21 per cent poor and 2 per cent bad ecological status.
In the case of nitrate pollution the majority of sites with elevated nitrate concentrations occur in the southeast. The contrast between the western and eastern rivers is not as immediately apparent for phosphate as nitrate pollution, however half of the surveillance monitoring sites in the South-Eastern River Basin District (SERBD) would not achieve Good Status in 2008 based on phosphate levels.
High Ecological Quality River Sites
High ecological quality at river sites is an indicator of largely undisturbed conditions and reflects the natural background status or only minor distortion by anthropogenic influences. Such sites are used as reference sites from which deviation in quality is measured. These sites play an important part in conserving individual species and overall catchment biodiversity and must be protected under the WFD.
The percentage number of high quality sites has almost halved in the last 21 years from almost 30 per cent of the total sampled in the 1987-1990 period to less than 17 per cent in 2006-2008. The seven-fold decrease in sites attaining Reference Condition (Q5) is particularly striking. These sites now comprise less than two per cent of the total surveyed.
Of the 271 lakes assessed for WFD Interim Biological Status in 2008, over 55 per cent had at least good status.
Only very modest nitrogen loading was recorded in 2008 for the 75 lakes on the surveillance monitoring programme, and 81 per cent of surveillance lakes sampled in 2008 were of good or better status for phosphorus concentrations.
For references, please go to http://www.eea.europa.eu/soer/countries/ie/freshwater-state-and-impacts-ireland or scan the QR code.
PDF generated on 23 Feb 2017, 06:59 AM