Clean, small rural sewage schemes which serve dispersed rural populations are possible - but at a cost, according to the Swiss experience.
While in Switzerland the Irish expert group visited the relatively vast Valais region, a canton with a low population density set in an environmentally sensitive mountain landscape.
The group visited the mountain village of Unterbach, where the population of about 450, grows in the high tourist season to almost 3,000.
According to Mr Daniel Vogel, president of the municipality of Unterbach, the influx and exodus of visitors means the population of the village in the low season may be quite dispersed. Despite this, 94 per cent of all homes are connected to the village waste water treatment plant.
Development plans are made about once a decade and those who want to live outside the area zoned for development must pay the cost of connecting to the sewerage scheme.
With obvious parallels for the Republic, while the land might be cheaper further out, the cost of connection is obviously much higher.
The cost of the sewage plant which was constructed between 1998 and 1999 was about €5.5 million and this was provided through state and conton subsidies and a bank loan taken out by the villagers.
The loan and the running costs are financed by a "tax" on construction based on the number of rooms, and on existing homes by the number of taps or the square footage of the house.
While there are other criteria to be met before permission is given to build away from the village the need to connect to the sewerage system has become an effective development control.
