Irish Water plans to spend almost €400m on replacing lead pipes - but only outside properties.
The pipes will be stripped out over the next 10 years to help stop contamination.
Water treatment is to be used in the interim.
The utility will publish a draft today of plans to remove lead from our drinking water.
The plans will be open for public consultation until September.
In the meantime, those living in homes built before 1980 are being urged to check for lead.
Irish Water estimates that around 180,000 homes and hundreds of commercial and public buildings still have internal lead plumbing.
Mark McAuley is Irish Water's supply strategist.
He says pipes will only be changed outside a property - anything inside is the owner's responsibility.
"If you identify lead within your property and you replace the lead plumbing within your own property, we will then replace the lead on the public side", he told Newstalk Breakfast.
Asked how much it could cost and how long it may take, Mr McAuley said: "Typically the cost ranges - it depends on the property and the complexity of the plumbing set up within the property - but typically the range would be from €1,000 to €5,000."
However there is a grant scheme available to cover those costs from the Department of Housing, Planning and Local Government.
He says this is a "health objective and a priority" - and that regardless of whether or not people have paid their bill, their external pipes will be replaced.