This paper deals with some theoretical investigations and experimental correlations of the kinetics of B.O.D. and faecal bacteria reductions in a series of stabilization ponds. A differential equation governing the B.O.D. and faecal bacteria concentrations in a pond is derived, based on the monomolecular law and in terms of the volume of the pond, the influent and effluent flows, the B.0.D. and faecal bacterial concentrations and the monomolecular constant K. Solutions to the equation are given. The theoretical relationship between the concentrations in a series of ponds and a river is derived and the superiority of a series of ponds over a single pond of equivalent total volume is established. A criterion for the prevention of anaerobic conditions in the pond is presented, which indicates that anaerobic conditions depend upon the B.O.D. concentration in the pond and the depth of the pond.
The paper descriptionbed various aspects of design, construction and economies of a ten-million gallon reinforced concrete reservoir which was designed and constructed in accordance with the Institution of Civil Engineers' Code of Practice. The aim in the design was primarily to inhibit cracking and to ensure a high degree of water tightness.