Investments, performance and economic impact in the wastewater sector: correlations and trends in the period 2012-2022

Abstract This study analyses the relationships between investments, network expansion, operational costs, tariffs and environmental compliance in sewage services in Romania, over the period 2012–2022. Using a quantitative methodology based on correlation matrix and principal component analysis (PCA), the research highlights the interdependencies between key indicators. The results show that connected population and tariffs are determinants of economic sustainability, while investments indirectly contribute to improving environmental compliance. The study highlights the need for an integrated strategy that combines financial efficiency, infrastructure modernization and environmental compliance to ensure long-term sustainability.