Minister for the Environment Phil Hogan said septic tanks can be registered for €5 from today for the next three months, but inspections will not commence until next year.
He also said he could not make any commitments in relation to potential grant assistance. Online and written facilities for registration have been developed.
"As inspections will not commence until next year and as it is not possible to predict the future, it is not possible for me to make any commitments in relation to potential grant assistance for owners whose systems might be found to require remediation," he said.
Mr Hogan told the Oireachtas environment committee there was no doubt that remediation work on some on-site systems would be necessary.
The payment of a registration fee is intended to cover the costs of administration of the register by the water services authorities and of the inspections to be carried out.
Householders can register their systems from today and a public information campaign will inform people about how to register.
"Certainly we are in a very difficult financial position in the country but we are not getting into the business of discussing the budget in June. The budget is in December 2012. There'll be no further discussions in the lead up to that particular budget," Mr Hogan said.
The committee meeting was heated at times. Independent TD Mattie McGrath said there had been "deliberate confusion and blackguarding of the public" and said that "lies were told".
Mr McGrath was asked to leave the committee room by chairman Ciaran Lynch of Labour, who advised him to be "more temperate".
Fianna Fáil deputy Éamon Ó Cuív also accused Mr Hogan of telling "lies". He withdrew the allegation but insisted the Minister had been "totally untruthful".
