A boil-water notice is to remain in place for 30,000 residents in the greater Ennis area until February 2009.
The joint precautionary notice by Clare County Council, Ennis Town Council and the Health Service Executive (HSE) that remains in place advises that children under five years, people in care and those vulnerable to infection should boil their water before drinking from the public supply.
Yesterday, Clare County Council signed an €8.3 million contract to build a temporary water treatment plant for the greater Ennis area.
Former junior environment minister, Batt O'Keeffe told the Dáil in 2005 that the permanent plant would be in place by late-2007.
However, it was confirmed yesterday that the plant would not be in place until February 2009, with work expected to commence on the facility this year.
Two years ago, Ennis's local water supply was hit by a series of boil notices after cryptosporidium was found in the water supply in June 2005.
In spite of spending €2 million on a temporary water treatment plant that is currently operational and repeated re-assurances from the local authorities that the water quality was of a high standard, a partial precautionary boil notice remains in place for vulnerable members of the community. The quality of the Ennis water supply became a general election issue last May.
Yesterday Fine Gael's Joe Carey TD said: "While welcoming the signing of today's contract documents, it is unacceptable that the precautionary boil notice will be in place for 3½ years by the time the permanent plant opens in February 2009."
He said the residents of Galway could avail of a water-voucher system within five weeks of the water scare in the city, while businesses could avail of a 10 per cent rebate in rates. "Nothing of the sort has been put in place for the people of Ennis."
Clare's mayor, Cllr Patricia McCarthy (Independent), said: "The people of Ennis have been waiting a long time for this day."
On the delay in getting to the contract signing stage, she said: "There have been a number of difficulties, but the difficulties are past."
The contract signed yesterday is with EPS/Bowen Construction of Mallow, Co Cork, and work is expected to commence in late autumn-early winter, with design work to be carried out until then.
Ms McCarthy added: "When complete the project will be instrumental in meeting the future development needs of Ennis.
"Along with the construction of the Ennis bypass and the designation of the town as a hub under the National Spatial Strategy, the new water treatment plant will assist further in attracting focused investment into the area."