Integrated Water Quality Assessment 2013

The EPA undertook an assessment of the 2013 water quality monitoring data in Ireland.  This assessment covers the entire Western and South Eastern River Basin Districts (RBDs) and the parts of the North Western and Neagh-Bann RBDs that are in the Republic of Ireland*.  It also includes overall national statistics.

This assessment presents the latest monitoring data, an assessment of the data and a focus on key issues that affect water quality in each of the four RBDs studied.

The assessment of water quality is presented using four Key Indicators:

1. Physico-Chemical Quality

2. Biological Quality

3. Pressures

4. Overall (Integrated) Quality

Under these headings the key issue, i.e. nutrient enrichment is examined.

Overall Summary

Nutrient enrichment (excessive inputs of phosphorus and nitrogen) is the main cause of water pollution in Ireland.  Overall in 2013, 59% of river monitoring stations and 59.6% of lake monitoring stations displayed a high level of compliance with the relevant phosphorus Environmental Quality Standard (EQS).  The percentage compliance of river stations with the phosphorus EQS in the individual RBDs is presented in Table 1 below.

RBD% River Stations achieving at least 'Good' Compliance% River Stations achieving 'High' Compliance
Western 96 93
South Eastern 71 50
North Western 84 67
Neagh-Bann 59 28

Table 1 - Percentage compliance of river stations with phosphorus EQS

Analysis of long-term trends indicates that ortho-phosphate levels in rivers have been steadily declining since the 1990s.  The mean ortho-phosphate and nitrate concentrations at groundwater monitoring locations have also decreased over the period 2007-2013.  The compliance of river and lake monitoring stations against the physico-chemical EQSs (in particular ortho-phosphate, but also nitrate and ammonia) is usually complimentary to the biological assessment at the same monitoring point.  Despite indications of an overall decrease in the nutrient concentrations, the number of river sites achieving 'High'  biological classification has decreased for all four RBDs.

Diffuse agricultural pollution and waste water discharges are the main causes of surface waters failing to achieve at least "Good" biological classification in the RBDs assessed.

*The remaining water bodies in the country (Eastern, South Western and Shannon RBDs) will be included in future such assessments.

Learn More

Western River Basin District

South Eastern River Basin District

North Western and Neagh Bann River Basin Districts