Waters in Clarinbridgge and Kilcolgan rivers were one of three in the west that have displayed less than good compliance with water quality standards.
The Environmental Protection Agency (EPA ) this week published three Integrated Water Quality Assessments for 2013 which showed that 60 per cent of rivers and lakes in Ireland achieved a high standard of compliance with the phosphorus Environmental Quality Standards, which are a key chemical indicator of water quality.
By contrast, more than 90 per cent of rivers and lakes, in the Western River Basin District display a High compliance with these standards. Only Clarinbridge and Kilcolgan Rivers (Galway ), Ballindine River (Mayo ) and Tubbercurry River (Sligo ) displayed ‘less than good’ compliance with the standards.
In the assessment period 2011–2013, Connemara lakes, Aughrusbeg and Tully improved from Moderate to good compliance with key chemical quality standards (including phosphorus ) and Nambrackmore Lake improved from Good to High compliance. Carrowmore Lake, Co. Mayo, which is an important angling amenity and drinking water source, declined from Good to Moderate compliance with these quality standards due to elevated phosphorus results. Loughs Corrib, Mask, Cara and Cullin continued to show a high level of compliance with these standards.
The Western River Basin District is made up of 89 water catchments or drainage systems, includes counties Mayo and Sligo, a proportion of Galway and small parts of Roscommon and Clare. The main cause of water pollution in the Western River Basin District is nutrient enrichment, caused by an excess of phosphorus and nitrogen inputs.
Analysis of long-term trends, indicate that concentrations of phosphorus in all Irish water bodies (including those in the west ) have been decreasing since the late 1990s. In spite of this, only 80 per cent of river channels in the western region displayed a Good or better biological classification in the most recent assessments (2011–2013 ), with only 27 per cent achieving a high classification. Continued reduction in concentrations of phosphorus and nitrogen should result in improved biological classification of these water bodies.
Agricultural pollution (31 per cent ) and waste water discharges (26 per cent ) were the main causes of river monitoring stations failing to achieve at least Good biological classification in the Western River Basin District.
Commenting on the Western River Basin District Integrated Water Quality Assessment results, Alan Stephens, Regional Chemist, Castlebar Regional Inspectorate, EPA said:
“Phosphorus concentration is a key indicator of health for a lake, river, estuary or groundwater. There is wide regional variation in concentrations of phosphorus in rivers and lakes due mainly to historic agricultural practices. The availability and assessment of up to-date monitoring data and long-term trends will be crucial to identifying, protecting and managing the remediation of vulnerable water bodies”.
Furthering commenting on the Western River Basin District Integrated Water Quality assessments, Alan Stephens said:
“Phosphorus inputs to water bodies should continue to be reduced. Changes in practices are required to improve and protect water quality. Improved compliance with the Nitrates Directive to reduce agricultural pollution will be needed as well as improvements in waste water infrastructure and operational practices”.
For more information on the Western River Basin District (WRBD ) Integrated Water Quality Assessment Report, please visit: http://www.epa.ie/water/wm/intergratedwater/