Sewer networks are designed to collect and transport wastewater to treatment plants. However,
during wet weather periods stormwater runoff flows into these sewers and combined sewer
overflows (CSOs) occur. Damage to the nearby natural waters from these CSOs is noticeable.
This is because of the high pollution concentrations in CSOs. Controlling urban wastewater
systems is one possible way of addressing the environmental issues from CSOs. Therefore, this
research explores the development of a holistic framework that is intended to be used for the
multi-objective optimization of urban wastewater systems, considering water quality in both
sewers and receiving waters and the economics of wastewater treatment. Dry weather flows
(DWFs) and stormwater runoff water quality compositions were considered. Temporal and
spatial variations of the stormwater runoff were incorporated using pollutographs for different
land-uses.
