The European Commission is to pursue Ireland in eight cases for breaching EU environmental law.
Among the cases over which the Commission is taking action is one relating to the October 2003 landslide at Derrybrien, Co Galway, which caused severe damage to property and the local environment and killed around 50,000 fish.
The landslide was caused by work on Ireland's largest wind-farm project.
The Commission said: "Despite the environmental disaster and the failure to properly assess in advance the risks that the project presented as a result of soil instability, the Irish authorities did not given any commitment to carrying out a fresh environmental impact assessment (EIA), including consultation of the public concerned, before resumption of work at Derrybrien.
"This case also addresses a wider problem, namely that, as a result of Irish legislation and enforcement practice concerning retention of illegal developments, certain projects, such as quarrying and pig-rearing, are being carried out or intensified before an EIA is undertaken or considered.
"The public and the environment and thereby potentially exposed to damage and nuisances."
Labour MEP Proinsias De Rossa
The Commission said its action in these cases is aimed at reducing agricultural and sewage-related water pollution, protecting citizens from noxious sewage odours, ensuring safe waste disposal, ensuring that significant projects are properly environmentally assessed, restoring an important nature site and getting Ireland to participate more fully in wider efforts to curb air pollution and protect the ozone layer.
It said it has a duty to ensure that each Member State lives up to its commitments to safeguard the environment and human health.
Labour MEP Mr Proinsias De Rossa said today's announcement was "a terrible indictment of this Government's environmental record.
"Ireland has one of the worst records when it comes to respecting European environmental laws. In the five years to 2002, the Commission issued more 'first warnings' over environmental breaches by Ireland than against The Netherlands, Austria, Sweden, Finland, Luxembourg and Denmark combined - 85 versus 77.
"During this period, with just one per cent of the EU population, Ireland was responsible for 16 per cent of all first warnings while Ireland received twice as many first warnings than France, a country with over ten times our population," Mr De Rossa said.
"The Government now has three months at most to get its house in order. If not, Ireland could end up in the European Court of Justice on all of these breaches. The Environment Commission has previously said that 'Ireland's nature is stunningly beautiful'. It won't remain so under this Government," the MEP said.
The Green Party chairman and TD Mr John Gormley welcomed the decision by the Commission to pursue infringement proceedings against Ireland.
He said he was "particularly pleased" a case he brought to the attention of the Commission in relation to the "appalling smell" from a new sewerage plant in Ringsend is to be pursued.
"The Irish attitude to EU environmental directives is cavalier in the extreme and the Irish Government deserves to be punished for these transgressions.
"Not only has the environment suffered but people's lives have been adversely affected by the Irish Government' failure to properly implement EU environmental law. I hope this a salutary lesson and that Minister Dick Roche and his colleagues will no longer thumb their noses at the Commission."