The European Commission has initiated legal action against the Government for failing to comply with EU rules on water quality.
The decision to send Ireland a "reasoned opinion" follows the investigation of three complaints about failures to properly investigate and authorise groundwater discharges.
The complaints relate to a landfill site at Avoca, Co Wicklow, an animal burial ground in Ballinrobe, Co Mayo, and a hotel at Creakan Lower, New Ross, Co Wexford.
The Commission discovered that no groundwater authorisation had been given for the animal burial ground, that wastewater disposal at Creakan Lower had been going on for several years without authorisation and that the Environmental Protection Agency had failed to properly ensure groundwater protection at Avoca.
The Commission believes that Ireland interprets the Groundwater Directive too restrictively, failing to provide for adequate groundwater investigation and authorisation.
The Commission has also decided to send Ireland a reasoned opinion for failing, under the Bathing Water Directive, to recognise and protect a bathing area at the Pier, Tramore, Co Waterford.
Announcing the action against Ireland and seven other member-states, the Environment Commissioner, Ms Margot Wallström, said the Commission was determined to ensure that governments fulfilled their obligation to keep water safe.