NPE were engaged to perform a critical bypass required in order for our client to complete the final stage of a major project building additional capacity and redundancy into the local water authorities wastewater network. NPE’s role was to install, commission and manage the sewer via a pumped overland bypass in order to provide a dry double isolated pipeline that would allow our client to complete their tie works. The window for installation and completion of the works was extremely tight. Access was difficult as the alignment ran parallel to a major roadway where the pipe alignment snaked through a sensitive green site where disturbance to the local flora was to be kept to a minimum.

NPE designed a sewer bypass system where we supplied 4 x BA300E pumps to ensure that the nominated PDWF rate of 650 l/s with 100% redundancy could easily be achieved whilst still providing additional capacity to meet higher PWWF that were likely to be encountered during the tight project timeline due to the stormy and unpredictable wet weather the area had been receiving.

Due to the critical nature of the project and tight time frames of operation, NPE provided 24/7 on-site monitoring in conjunction with the telemetry system to ensure that the risk of overflow was removed in the event of ramping the bypass up to cater for PWWF due to the shallow collection manhole for the bypass and presence of an overflow point upstream which meant levels within the bypass collection manhole had to be kept to a minimum at all times.