Mr. Se?n Laffey:

I made those comments about THMs. If you are taking water out a river during the summer, it is calm and there is no heavy rainfall so the water is quite clear and settled and the plants can deal with them. The plants were not designed to deal with extreme events. Plants are built with a certain headroom and additional capacity, and when they are new they can take shock events a lot easier than when they are slightly older and working more towards the upper end of their capacity.