Sustainable sewerage infrastructure projects are essential in achieving sustainable development, as infrastructure directly affects all measures of such development. However, sewerage infrastructures face a variety of challenges and threats to their sustained performance throughout their life cycle, including effects of aging, aggressive environmental factors, inadequate design, underfunding, improper operation, and maintenance activities. These challenges lead to the enhancement of the risks of failure, for example, sewer leakage, overflow, and odor. These issues can have serious impacts on the environment, public health and safety, the economy, and the service lives of assets. Only a few research has focused on assessing sustainability at the project level, and to the best of researchers’ knowledge, no study has assessed sewerage throughout its project life cycle. In response to this issue, this study proposes a sustainability assessment framework that focuses on all aspects of sustainability throughout the project life cycle. Furthermore, this framework supports the decision-making process throughout the life cycle of assets, ensuring the long-term sustainability of the projects and providing greater transparency for the stakeholders.