The polluted flow, including those from the expedient connections, cross-connections between the foul water sewerage and the stormwater drainage system in the area found their way into the existing Cherry Street Box Culvert and in turn discharges into the New Yau Ma Tei Typhoon Shelter. Therefore, a DWFI at the CSBC to intercept the dry weather flow (DWF) inside the box culvert and a sewage pumping station was constructed to pump the intercepted DWF to the existing sewerage network in order to improve the water quality and accociated odour. To monitor and minimize the odour nuisance induced by the box culvert outfall, real-time 24 hours continuous H2S monitoring are carried out.