Permission has been granted for upgrades to the existing Crossdoney Water Treatment Plant in Cavan.
The works, at Gartbrattan, will see the construction of a new water clarification process tank and a below-ground pumping chamber.
It will also include modifications to below-ground pipework.
The application notes that the existing Water Treatment Plant is "currently not capable of removing elevated levels of organics from the raw water".
The upgrade works "are designed to provide additional water treatment processes to ensure adequate organic removal" and to increase the volume of water that the treatment plant can deal with.