Studies on Household Sewage Disposal Systems, Part III, 1954,' the third progress report of a series, deals with continuance of studies on home septic tank details, including multicompartmentation arrangements, capacity, shape, depth, surface area, outlets, sludge and scum accumulations, effect of flow variation; soil absorption factors, including appraisal of absorption capacity, physical, chemical, and biological clogging behaviors, intermittent dosing; and effects of water softener brine and ground garbage. Additional undertakings reported include studies on detergents, evapotranspiration as an influence in effluent disposal, flow distribution devices, sludge and scum gaging devices, tank improvements to facilitate maintenance, and the effect of caustic soda.