The Creeslough water supply has been removed from the Environmental Protection Agency's remedial action list.
The latest report from the EPA shows that Irish Water has reduced the number of schemes on the RAL in Donegal from 11 to 4, since 2015.
Over 3000 people in Creeslough now have safe drinking water as the water supply has been removed from the EPA's remedial action list
The Creeslough Water Supply has been given the all clear by the EPA following extensive investment and upgrade works by Irish Water working in partnership with Donegal Council.
Works are continuing on the remaining four Donegal water supplies with a view to having them removed from the RAL as soon as possible.
The water supplies currently on the RAL are Greencastle, Glenties, Milford and Letterkenny. All four water supplies should be removed from the RAL in 2020.