The State could be brought before the European Court of Justice for failing to comply with EU environment directives.
The European Commission (EC) is to start infringement proceedings against Ireland for failing to provide information about a number of complaints relating to sites in Dublin city and Counties Cork, Limerick and Roscommon.
France, Spain and Greece have also been identified for similar breaches.
If the EC's latest letter to the countries is not met with a "satisfactory reply" within two months, then the Commission could send a final written warning before taking action at the European Court of Justice.
Environment Commissioner Ms Margot Wallström said: "If Member States fail to provide promptly the information requested, the Commission cannot deal efficiently with environmental complaints that we receive from citizens. I would, therefore, urge Ireland, France, Spain and Greece to provide the assistance requested."
One of the complaints in Ireland relates to discharges of oil into water next to a special protection area at Poolbeg Peninsula in Dublin.
The Commission is also seeking information about an industrial facility in Fermoy, Co Cork, where information has been sought about alleged breaches of directives governing waste disposal.
Similar information was sought about a waste facility in Ballysimon, Co Limerick, following a complaint last August.
Irish authorities have also failed to provide information on a complaint about a marina development on Lough Ree, Co Roscommon, allegedly affecting water quality.
The Commission is also seeking information about allegations of irregularities in the required paperwork for waste exports from Ireland last August.
A Department of Environment said it would be responding to the Commission shortly.