Dáil Éireann debate -
Wednesday, 25 Apr 1990

Vol. 397 No. 9

Written Answers. - Chlorine — Cancer Link.

Charles Flanagan

Question:

275 Mr. Flanagan asked the Minister for the Environment , in light of recent studies suggesting an apparent link between chlorine and forms of cancer, particularly in areas with a high concentration of peat bog water and, having regard to the use of chlorine by local authorities in public water schemes in the midlands, if he will undertake a major review of the use of chlorine as a water purifying agent by local authorities; and if he will make a statement on the matter.

Minister for the Environment (Mr. Flynn)

I am aware of research on the use of chlorine in the treatment of drinking water and the findings are kept under constant review. I am advised that the controlled use of chlorine provides the most effective means of disinfecting water and maintaining protection from microbiological contamination throughout distribution systems. In general, the treatment processes at public water supply schemes remove substances, including peat, which cause colour in water, and chlorine is used as a final treatment only when such reactive substances have been eliminated.

The quality of drinking water is controlled by the European Communities (Quality of Water Intended for Human Consumption) Regulations, 1988, which set a statutory limit of 100 micrograms per litre for the presence of organo-chlorine compounds in drinking water. The regulations also provide that substances used in the preparation of water must not directly or indirectly cause a public health hazard and residual chlorine or other disinfectants used in the treatment of water must be monitored to ensure that this requirement is met.