This presentation describes how the City of Gothenburg was able to address emerging challenges within its sewerage system by developing a digital twin. Gothenburg, located on Sweden’s west coast, is one of the rainiest cities in the country. Heavy rainfall causes large loading variations at the regional Rya water resource recovery facility (WRRF). In addition, around 25% of the sewers in the City are combined, increasing the risk of flooding and discharge of untreated wastewater into the surrounding waters. Gryaab AB is the regional wastewater utility that serves Gothenburg and surrounding municipalities. Gryaab owns and operates the Rya WRRF and the tunnel system that transports wastewater to Rya WRRF. Gryaab saw the potential and developed a digital twin to help better manage its sewerage system. Deployment of the digital twin allowed Gryaab to get better real-time information about events in the tunnels and generate accurate predictions of potential issues and peak pressure on the system. This allowed them to reduce urban flooding and optimize overall performance of the system. Simulations indicate that yearly CSOs may, ideally, be reduced by 65% and bypass volume at the WRRF by 85% through dynamic operation of CSO sites and increased utilization of tunnel volumes. The digital twin allows Gryaab to act proactively. Staff can make decisions based on comprehensive, real-time data and prognosis and even allow direct implementation of the digital twin’s suggested setpoints in the SCADA-system. In short, the digital twin is used for gaining better real-time control and improving the operation of the sewer system, both today and in the future.
