The European Commission has said that geological and soil conditions in many parts of Ireland may make it difficult for septic tanks to function without causing pollution.
The Dublin office of the EU issued a statement which sought to clarify what it said were a number of points which have arisen in media reports.
The statement said Ireland had not yet implemented EU legislation to monitor the 400,000 septic tanks throughout the country.
It warned that poorly managed or controlled septic tanks may cause significant harm to the environment and human health.
The septic tank issue has been controversial, particularly in the west of Ireland.
Over the weekend, Fianna Fáil deputy leader Éamon Ó Cuív said he would go to jail rather than pay the proposed new charges for the inspection and maintenance of septic tanks.
It is also estimated that 9,000 people in the Dublin area may have to pay the charge and a public meeting on the issue is to be held in Balbriggan later this week.
