Impact evaluation of alternative wastewater management projects on the water quality of an urban stream

The impacts of proposed alternative wastewater control schemes for restoring the water quality of an urban stream, which is highly polluted by urban wastewater in the city of Kandy in Sri Lanka, are investigated. The paper consists of the identification and quantification of the spatially varied wastewater discharges and accompanied pollutant loads along the 4km length of the stream, development and verification of a one-dimensional water quality model and the predictions of total-N, BOD5 and DO concentrations along the stream. The different levels of improvement in the stream water quality during the dry weather season that could be expected by the implementation of two different wastewater control projects are elaborated by the model application.