Domestic wastewater comprising of raw sewage and sullage is predominately emptied directly into open water bodies and surrounding soils in Port-Harcourt city and its coastal communities. This practice exists as a result of the absence of functional sustainable wastewater treatment plants in the area. To address this problem, a prototype waste treatment plant was designed for selected households in Opobo town, Rivers State, Nigeria. The treatment units designed comprise of a sump and pump house unit, an approach channel, a screen chamber, and a primary and biological treatment unit. The aeration and settling tanks have a tank volume of 11.1m3 and 13.45m3 respectively; with an estimated BOD removal of 60 - 70% and 20 - 30% suspended solids.