The Environment Minister, John Gormley, has said Ireland's groundwater is polluted to an unacceptable degree.
This follows a report from the Environmental Protection Agency which shows that 60% of groundwater samples here are polluted with human and animal waste.
A quarter of groundwater locations exceed the national guidelines for nitrates.
Mr Gormley signed new water regulations into force today.
He's promising that these measures will begin to address the problem.
He added: "It's unacceptable that people continue to pollute and we do know the source of this pollution and it needs to be addressed.
"We've started to address this by introducing measures over the summer, more stringent fines for those who pollute our water.
"Today, I've given the EPA extra powers to regulate local authorities' sewage treatment schemes."