Dr. Eimear Cotter:

Three parameters will dictate nitrogen coming into our rivers. One is the type of soil. Freely drained soils will have more nitrogen leaching, for example. The other two parameters are farming practices and the weather. A mix of these three parameters will determine the amount of nitrogen leached from the land into the rivers. In terms of picking out one particular year, we can drill into this for the committee to enable an understanding of what exactly is happening there. It is, however, a combination of these three factors.