An extract from RTE Prime Time, Thursday, March 16, 2017 deals with THMs (trihalomethanes) in Ireland's drinking water. Up to 400,000 people could be affected by potential cancer causing chemicals.
To read further information on this issue see Friends of the Irish Environment article. They have been highlighting this issues for a long time. Or there are many articles on this site which you can search 'Archives' using phrases like Trihalomethanes or Chlorine.
Source: RTE Prime Time March 16 2017