Minister for the Environment John Gormley has said he had no alternative but to increase the penalties for breaching water quality regulations.
Farmers and others who breach the newly-introduced nitrates regulations face fines of €5,000 and three-month prison sentences at the lower end of the scale, rising to fines of €500,000 and one year's imprisonment.
"Farmers are responsible people and they are the custodians of the land, and for the most part they do a very, very good job," Mr Gormley said. "The people who have something to fear are the polluters, and I will make no exception, be it a local authority, an individual or a farmer, and that is why I increased the penalties."
The Minister said he had an obligation to ensure that an infringement case being taken by the European Commission against Ireland was taken off his desk, because Ireland could be facing very heavy fines.
He said that the derogation given to farmers to use higher levels of nitrates on their farms was a trade-off for higher penalties and he thought this was a fair deal. "It think it is also in the best interests of the environment and of sensible farming," he said.
Asked how he would deal with other polluters, such as local authorities, the Minister said that many of our sewerage systems needed to be improved dramatically. "I am committed to do that and I will be making an announcement shortly about the roll-out of a programme to deal with that. It is not acceptable that our waterways are polluted. It is not acceptable that you cannot swim in the River Shannon, and the very idea that you could not drink tap water in this country was inconceivable some years ago," he said.