The Oireachtas committee looking at the future funding of water is expected to make its final recommendation on water charges next week.
It now looks as though only people who "wilfully" waste water will pay for it, Sinn Féin TD and committee member Eoin Ó Broin has said.
Its final report will define wastage as being 1.7 times the average usage. This is 70% above average.
Householders will get a notice in the post if they are above the threshold.
A new term, 'wilful waste', is being introduced in the water charges debate. But what does it mean? #SinnFéin's @EOBroin explains pic.twitter.com/jK8J1LJoWz
— Morning Ireland (@morningireland) March 30, 2017
They will have six months to correct the wastage or fix a leak and there will be incentives to fix the leak.
If they do not address or correct the matter after six months they will be levied with a charge.
It is understood that 8% of householders, representing 70,000-71,000 householders, will be affected.
There will also be medical exemptions.
Speaking on RTÉ's Morning Ireland, Mr Ó Broin said Ireland can still meet European Union legal environmental requirements by funding water and repairs to the system through general taxation, stating that Scotland manages to do it.
The committee has examined the report of the Expert Commission on the Future Funding of Domestic Water Services, and will send its final recommendations to the Dáil where a vote will take place.
However, former minister for the environment Alan Kelly has said he believes what is being proposed by the committee is illegal and will not meet the polluter-pays and cost-recovery principles.
He said unless every household has a meter waste cannot be measured.
Mr Kelly said the EU will impose massive fines on Ireland for failure to comply with European law.
Fine Gael's Kate O'Connell said the future funding of water will include a levy or penalty for excessive water use and this does not equate to the abolition of water charges.
Ms O'Connell, a member of the committee, has said the draft report issued yesterday says an allowance per household or per person will be set and then anybody who uses over that allowance either consciously or for particular domestic needs will be charged for "excessive use".
Ms O'Connell told RTÉ's Today with Sean O'Rourke that the draft report does not suggest water charges will be abolished entirely but refers specifically to a penalty or levy.
Green Party leader Eamon Ryan described the proposed system as "madness" and said without a proper metering system it is impossible to properly measure wasteful use of water.
He said a fine-based system would see around 70,000 people facing fines.
Mr Ryan said a referendum on the ownership of water would be welcome but the real issue is how wasteful use is managed. He said it is difficult to measure it without a metering system.
