The owners of a Co Roscommon quarry have admitted the diesel spillage, which has left 5,000 households without water, may have come from an oil delivery to their plant.
As the water shortage caused havoc to life in northeast Roscommon, Hanly Brothers Laragan issued a statement yesterday on how hundreds of gallons of diesel polluted the water system.
"The likely source is adjacent to the perimeter of the HBL quarry site and the spillage appears to have occurred during a routine diesel delivery by an oil company last Friday," said the company. It has been in operation for almost 40 years and is the largest employer in the region.
"The matter may be the subject of litigation with the oil company. We await conclusive findings from Roscommon County Council and have committed all available resources to assist in the clean-up operation."
The identity of the oil company was not revealed and there was some speculation that the spillage may have taken place outside the HBL plant.
Roscommon county manager John Tiernan told a meeting of the county council on Monday afternoon, before the HBL statement, that the council would pursue the polluters once they were identified.
The Hanly family is involved in a large number of businesses in the region, including the development of a luxury castle and estate at Lough Rynn near Mohill.
Several schools in the affected area closed down yesterday as the county council said the water shortages would continue at least until tomorrow.
Paul Costello, principal of Scoil Mhuire secondary school, Strokestown, said he had to close the school when he found the water level was extremely low. "It would have been impossible to carry on usual activities for the 450 students and staff," he said.
Council officials have taken steps to seal off the stream that is carrying the diesel into Lisheen Lake, while tankers of drinking water have been placed in Strokestown, Elphin, Rooskey and Tarmonbarry.
Ciarán Madden of the county council said: "We are making progress, but it will be Thursday, at the earliest, before water comes back on. We have made special arrangements to keep water supplied to two nursing homes in Rooskey and Elphin."
Amid fears that the water crisis could cause health problems, a local councillor has made a call for the Army to be brought into the area if it drags on into the weekend.
"People who have solid fuel heaters in their house and heat boilers off them can't do that now," said Eugene Murphy (Fianna Fáil.)
"I am very concerned about old people living on their own, particularly as the weather is very cold."