Effective Risk Assessment of Complicated EPC Projects: A Case Study of Wastewater Treatment Plant Projects

Risks are inevitable in engineering, procurement, and construction (EPC) projects. Wastewater treatment plant (WWTP) projects, which play a crucial role in enhancing environmental sustainability and promoting national climate-resilient development, are frequently delivered by the EPC approach. However, effective risk assessment (RA) processes tailored to complicated EPC projects are still lacking. This research aims to develop a robust RA process through an empirical study of EPC-WWTP projects in Vietnam’s Mekong Delta region. The proposed RA process includes six key steps: obtaining potential EPC risks by an intensive literature review, identifying suitable risk drivers by a prepilot survey, evaluating suitable risk drivers by semistructured interviews, prioritizing risk factors by a questionnaire survey, confirming risk factors by statistical analyses, and validating RA outcomes and proposed RA process by a focus group discussion with Delphi method. RA’s outcomes indicate that risk drivers in the project preparation phase critically impact subsequent phases. Of 67 risk drivers, seven key risk factors that heavily impact EPC-WWTP projects are (1) preparatory project deficiencies, (2) legal and land acquisition hurdles, (3) management and stakeholders’ collaboration challenges, (4) contractor performance issues, (5) bureaucratic complications, (6) unforeseen site conditions and others-related, and (7) operational and maintenance gaps. The validated RA process can be adopted for complicated EPC projects and be a benchmark of RA for other large-scale projects. Practical Applications: Risks are inherent in engineering, procurement, and construction (EPC) projects, including wastewater treatment plant (WWTP) projects that are vital for environmental sustainability and national climate-resilient development. However, effective risk assessment (RA) processes tailored to the complexities of EPC projects remain insufficient. This study addresses this gap by developing a robust RA process through an empirical study of EPC-WWTP projects in Vietnam’s Mekong Delta. Although specific to the Mekong Delta, the validated RA process establishes a foundation adaptable to other complicated EPC projects and regions. The proposed RA process guides project stakeholders in identifying and evaluating risks for further effective responses. Notably, the seven key factors identified in this study can serve as a foundation for future quantitative analyses across the project life cycle (PLC) to measure interdependencies and implement timely countermeasures. © 2025 American Society of Civil Engineers.