The details of over two thousand Clare County Council tenants have been provided to Irish Water.
The local authority has confirmed that those affected will receive letters to confirm their details are being handed over to the new state utility.
It's as Fianna Fáil calls on Irish Water to destroy the information it has received from councils across the country.
Clare County Council is writing to 2,300 tenants to inform them that their name and address details are being provided to Irish Water.
The Council says this is to enable Irish Water to validate accounts and charge households for water as a utility.
The local authority also says it was obliged by the legislation governing the company to provide the details of its tenants to it.
Fianna Fáil says this information like PPS details that were originally requested when Irish Water should be destroyed.
Spokesperson on Public Expenditure Deputy Sean Fleming says the handing over of the details is unacceptable.
While the state utility says the process is being carried out in consultation with the Data Protection Commissioner.
