Mr. Liam McCarton:

In respect of Deputy Stanley's first question, I think on-site systems are ideally suited. We have actually scaled down the technology into single houses. Reed bed technology has been developed quite extensively in Denmark. The Danish drive was zero discharge. Their catchments were sensitive waters so they wanted a design technology that would have zero emissions. They developed reed beds and willow beds in particular. Our work with larger systems was scaled back down to a single house and has been working quite well. In Ireland, there is huge potential that is low-tech and low-maintenance. The system we showed up there had no chemical or pumping costs associated with it. It was a gravity system. There is great potential in every area, particularly rural areas given the disparity of the population.

In respect of combined sewers, we are where we are. The issue relates to source point. It involves looking at where the water starts off. That seems to be where the potential lies. It is too late when it is in the combined system unless one is looking at the treatment plant in terms of reclaiming water there.

Thinking about catchments on the road, the question of where the water can be treated and used on site links back to rainwater harvesting. That is the potential in Ireland for combined sewer systems.