A translation of Guide de conception et de gestion Des Reseaux d'assainissement unitaires - etat de l'art, Paris 1996. The contents include: data on rainstorm run-off pollution; different types of weirs and accessories; computation and measurement of characteristics of weirs; evaluation and improvement of hydraulic output and its treatment; location, checking and choice of weir and its improvement; regulations concerning weir wastes; conclusions and strategy proposed for action and improvement of knowledge; and documents concerning computational methods. The case studies presented...