Development of infiltration factors for the estimation of urban separate wastewater flow in the Gippsland water catchment

Abstract

The estimation of wastewater flows is a fundamental requirement in the design of successful wastewater systems. The sizes and capacities of all major components are dependant on the predicted amount of wastewater flow that will originate from the contributory areas within the proposed catchment. The reliability of flow estimates depends on the accuracy of many assumptions. These include the future water demand and resultant wastewater production, population growth or decline, population density variations, socioeconomic changes, land use changes, and the maintenance of the wastewater system infrastructure. It is essential that the wastewater system has adequate capacity for peak wet weather flow, but can also function satisfactorily at minimum flows without operational problems (Great Lakes Upper Mississippi River Board of State Sanitary Engineers 1978, p. 12). The Colombo formulae (1) and (2), is a theoretically derived formula used to predict peak wet weather flow in separate wastewater systems. This formula has been by Melbourne Metropolitan Board of Works and Sydney Metropolitan Board of Works since the late 1960s (Coulsen, J 2004, pers. comm., 15 June), and is currently used at Gippsland Water. -- Complete abstract not reproduced here: see main document for complete abstract.