One of the country's longest-running boil water sagas could be within three months of a solution. 

The Co Roscommon town of Castlerea has suffered recurring boil water notices on its urban and rural water schemes for the past four years because of the parasite cryptosporidium. 

Irish Water has said an interim water treatment plant for the rural scheme will be operational in November and for the whole area by next May. 

Castlerea residents and businesses have been affected by almost constant boil water notices over the past four years. 

Irish Water has told RTÉ's Morning Ireland an interim solution for the rural scheme, which it describes as a "fully effective water treatment plant" will be "onsite within weeks" and will be operational by November.

Construction is currently under way amalgamating the urban and rural schemes.

Once the necessary piping is laid, the urban scheme will also be serviced by the new treatment facility.

Irish Water has said it expects the urban area of Castlerea to have full treatment by May next year at the latest and that the commercial aspects of the plans have been agreed.