Commentaries: Art. 5

The cantons shall ensure that general drainage plans (GDP) are drawn up which guarantee adequate waters protection in communes and effective drainage of housing areas.
The GDP shall specify as a minimum:
1. wastewater treatment areas that must be served by public sewers;
2. areas in which precipitation water running off built-up or sealed surfaces must be disposed of separately from other wastewater;
3. areas in which non-polluted wastewater must be allowed to infiltrate;
4. areas in which non-polluted wastewater must be discharged into surfacewaters;
5. measures by which non-polluted wastewater with permanent flow must be kept away from wastewater treatment plants;
6. the locations where wastewater treatment plantsmust be set up, and withwhich treatment system and with what capacity;
7. areas in which systems other than wastewater treatment plants must be used, and how, in these areas, wastewater is to be disposed of.
The GDP shall be adjusted if necessary:
1. to take account of developments in housing areas;
2. if a RDP is drawn up or changed.
It shall be accessible to the public.