Residents in Co Limerick staged a protest yesterday in their campaign to retain a water supply from a pure spring source.
Some 1,000 householders in the villages of Kildimo and Pallaskenry are supplied with water from nearby Bleach Lough, which has served them for 50 years.
However, Limerick County Council wants the residents to change from that group water scheme to a water supply from the Shannon Estuary scheme.
Residents have argued that the new water supply comes from the River Deel, which has been blighted by pollution problems.
Contractors engaged by Limerick County Council recently began laying pipes for the Kildimo/Pallaskenry water scheme and this angered residents.
They were joined in their protest yesterday by Independent MEP Kathy Sinnott.
Secretary of the Bleach Lough Retention Committee Dan Foley described the Deel as "one of the most polluted rivers in Ireland".
He said yesterday that people would be prepared to go to jail to prevent the new water supply.
"There is an abundance of good quality water here and the fact is that the council has been sending out false information about the water supply."
The council claims Bleach Lough does not have the capacity to sustain local development and is hindering the granting of planning permissions in the area. It also says Bleach Lough is a stagnant water source and any potential pollutant could cause havoc.