Threats to Our Waters

With more than 5000 lakes and 7000km of coastline and a network of rivers and streams crisscrossing the country, Ireland’s waters represent a precious resource in terms of economics, recreation and tourism. However, there has been a steady and serious decline in the quality of this resource over the last thirty years. This is not surprising given the dramatic change in our social and economic circumstances during the same period. Ireland has evolved from a nation of primarily low impact extensive agriculture to one of increased population, industrialisation and intensive agriculture.

Unfortunately, the political response to the unprecedented surge in the country’s economy, especially during the ‘Celtic Tiger’ years, has been inadequate in mitigating the immense pressures this growth has placed on our waters and in many cases it has compounded it with at best unwise, and at worst, corrupt planning decisions.

Pressures on Ireland’s waters – Water pollution & physical interference

By far the most serious water pollution problem facing Ireland’s waters today is the over-loading of the aquatic environment, beyond natural levels, with the nutrients nitrogen and phosphorous, in a process known as eutrophication. The main causes of this type of pollution are:

•  Agriculture: The spreading of slurry and fertilisers on farmland, especially close to water courses, in inappropriate weather conditions or in fields which are already saturated with nutrients, leading to nutrient loss from the land to waterways
• Local Authority Sewage Treatment Plants:  Despite significant investment in recent years, the most recent EPA  review of the treatment of waste water at 482 villages, towns and cities in Ireland found no waste water infrastructure or inadequate infrastructure at 112 locations and 192 treatment plants (51%) where the effluent quality is not meeting the EU standards due to waste water.
• Faulty and/or poorly sited septic tanks: Leaking of human sewage from private septic tanks of single houses (not joined up to ‘mains’ sewerage systems) poses a significant risk to water quality and human health. Tanks which are sited on unsuitable soil, or which are not emptied and maintained regularly result in effluent which either runs into nearby streams or down into groundwater.

Other pressures on our rivers, lakes and bays include:

• Run-off of nutrients and sediment from coniferous forestry plantations,
• Run-off from peat extraction operations (worked bogs),
• Discharges from large industry and smaller businesses, (often the cumulative effects of lots of small discharges is not taken into account in the licensing system)
• Water abstractions,
• Physical developments along river banks and shorelines
• Invasive alien plant and animal species
• Dumping of dangerous household and gardening chemicals and Run-off of chemicals from hard surfaces in urban centres and roads.

What is Eutrophication?

Eutrophication is the over-loading of the aquatic environment, beyond natural levels, with the nutrients nitrogen and phosphorous which leads to changes in the physical, chemical and biological nature of the water body and to a disruption of the delicate ecological balance in the water.  Excess nutrient result in excessive plant growth resulting in green ‘cloudiness’ in the water, lots of slimy green algae coating the stones and rocks at the edge and bed of the watercourse (‘algal blooms’) or an overgrowth of larger plant life. This in turn leads to depletion of the oxygen that is naturally dissolved in the water and which is necessary for fish and other animals to live in it. In extreme cases of ‘deoxygenation’ of a watercourse, serious fish kills can occur.