Eleven people charged in connection with illegal dumping were ordered to pay €11,500 at Limerick District Court yesterday.
Nine people received separate fines totalling more than €10,000 under the Litter Act, for dumping rubbish bags in different parts of Limerick city.
Two other people were fined under the Waste Management Act, after their rubbish was found dumped in a well-known rugby club.
The court heard that a massive pile of rubbish - consisting mostly of household waste - had been dumped at Richmond Rugby Club.
Limerick city litter warden Mr Reg Turner told the court that 150 youngsters use the rugby club, and that it will cost the council €3,000 to clear the waste there. Mr Turner said letters found in the rubbish were used to link two defendants with the rubbish.
Judge Peter Smithwick heard from the only defendant to appear in court, Trevor Kiely, Ballyclough Avenue, Limerick, that a man claiming to be from the council had asked for €50 to dispose of his rubbish.
"I had just moved into the house and I had a lot of rubbish. This guy came along and said he was from the litter department of Limerick City Council and that he would dispose of the rubbish. I paid him €50 but I never thought my rubbish would end up in Richmond Rugby Club," he said.
Judge Smithwick, told Mr Kiely that he had been conned by a "cowboy" and said: "Let this be a warning to you."
Mr Kiely was ordered to pay a fine of €50 and €50 in costs.
Jessica McNamara, St Brendan's Street, St Mary's Park, Limerick was fined €1,000 and ordered to pay €190 costs after she was also prosecuted under the Waste Management Act.
The court heard that a letter to Ms McNamara - who was not in court - was found in a pile of rubbish dumped in the rugby club.
Nine other people were also fined yesterday under the Litter Act.
Eight of them were fined €1,000 each and ordered to pay costs of €190, while one man was fined €500 and ordered to pay €190 in costs.
Speaking outside the court, Ms Maeve O'Grady, environment department, Limerick City Council, welcomed the fines, which she said have "trebled" in recent times.
"I would welcome the increase in fines and think they should be a deterrent to householders not to use illegal waste collectors," she said.
"In a lot of these cases, the guilty party is the collector. However the onus is on the householder to make sure that they are not using an illegal operator, and the fines handed out today should act as a warning to people," she added. Ms O'Grady said that each of yesterday's defendants received initial fines of €120 which were not paid.
"They now have just one month to pay the €1,000 fine plus costs of €190. If it is not paid then they could be put in jail for five days," she warned.