Characteristics of drainage structures
Urban drainage

As stated in the French General Instructions for the sanitation of built-up areas (circular dated June 10, 1976 from the Minister of Health, OJ of August 21, 1976), two principles must inspire the sanitation of built-up areas:

• evacuate all human and animal waste quickly and without stagnation, away from dwellings;

• prevent discharged products from contaminating groundwater or surface water.

Individual sanitation, which is definitive and systematic, is not recommended, even if the solution is economically better.

The collection of treated effluent in individual plants on a permanent basis is to be avoided, as...