A public health alert affecting drinking water in south Mayo for the past four months has been partially lifted by the Health Service Executive (HSE) West.
Residents using the Cong public water supply and group schemes attached to it and members of the Funshinaugh/Cross group water scheme have been told that they no longer need to boil tap water or use mineral water only for drinking, teeth washing and food preparation.
However, the notice continues for users of the Glencorrib group scheme due to "general quality problems unrelated to cryptosporidium", HSE West has said.
The alert was extended to south Mayo when the cryptosporidium parasite, which causes severe gastrointestinal illness, was detected in Galway city's old Terryland waterworks and in Headford, Co Galway, in March - and traced to contamination from Lough Corrib.
The parasite was mainly of the "hominis" type, derived from human sewage; 238 laboratory-confirmed cases of the illness have been confirmed by HSE West since January.