Dr. Jenny Deakin:

The sources of phosphorous, on a national scale, are 50:50 from agriculture and from urban wastewater. The portion that comes from humans is mostly discharged around the coast. Some 40% of the State's urban wastewater is discharged via Ringsend in Dublin. The Deputy asked how, when we look at a particular river, we distinguish it. As Dr. Cotter said, we start with the actual water quality and the signatures in the water - we take the sample and see what is in it - and then we go back up to the catchment to figure out how many cows and people are there, where the trees are and what activities go on for each of the water bodies we assess. It is quite a robust, integrated scientific assessment. We use peer-reviewed models-----