Pollution de la Basse-Seine lutte contre les mousses

The detergent foam pollution problem in the Lower Seine

Ingénieur en Chef des Ponts et Chaussées.

Résumé

This problem first became noticeable about twenty years ago when detergents which cannot be broken down biologically came into popular use. Very considerable quantities of these detergents are being used in France today. Until non-toxic detergents which can be broken down biologically are developed and their use is enforced, only partially effective measures against the foam pollution problem are the most one can hope for. Experimental instructions have been issued to gate-keepers at barrages on the Lower Seine to operate the bottom gate leaves so as to bring about drowned orifice flow conditions, which have been found very effective as a means of destroying detergent foam and preventing fresh foam from forming. Attempts are now being made to generalise this as normal operational procedure.