Mr. Se?n Laffey:

As Dr. Minihan said, THMs are a class of organic compounds that are formed when dissolved organics in the water interact with the chlorine that we use to disinfect the water. That is how we get THMs. Research has shown that exposure to trihalomethanes over a very long period of time can be carcinogenic so we take them very seriously. The issue with THMs is that they will form immediately they come in contact with chlorine but the longer they are in contact with the chlorine, the more formations of THMs we get, so as Dr. Minihan said, we have issues with the extremities of our networks because water out at the extremities could have left the plant five to seven days previously. Historically, we have had a problem with THMs in Ireland because a lot of our water sources are impacted by a lot of dissolved organic matter from bogs and so on, and the plants that were put in simply were not up to the highly technical challenge of removing that dissolved organic matter. We are moving on the issue. We have a case against us and we have a THM programme in place. We are spending millions of euro every year on the issue of THMs. It is not the case that our water supplies are getting worse. What is actually happening is that Irish Water has looked across all of our water treatment plants in terms of their trihalomethane risk profile and has initiated additional testing above what is required in the regulations. We are doing that in the plants and out on the network and we are finding THMs. This is bad news in the short term because ultimately, the remediation action list, RAL, goes up, that is, the numbers go up, but in the long term it is good news because it means we have identified a problem and we can put a plan in place to fix it.