The project involved upgrading the wastewater treatment plant serving the Candela (FG) urban area, on behalf of Acquedotto Pugliese, with the goal of addressing issues related to the plant’s physical condition and treatment capacity. The plant was designed for a load of 4,800 population equivalents (PE) and upgraded to ensure that discharges into the Rio Salso stream the limits set forth in Legislative Decree 152/2006, with a 95% reduction in organic matter and approximately an 80% reduction in nitrogen. To achieve this result, the effluent line was equipped with new screening and grit removal sections, while the existing equalization and biological denitrification and nitrification sections were upgraded and supplemented with a completely new air injection system and an enhanced secondary sedimentation tank. The sludge treatment line was upgraded with a new aerobic stabilization tank, a new post-thickening unit, and an enhanced mechanical dewatering system, while odorous emissions are controlled by dedicated collection and treatment systems. The project also included the replacement of deteriorated walkways, stairs, and footbridges, as well as the construction of a staff break room, in addition to the renovation of the perimeter fence, roadways, stormwater collection and treatment system, office space, generator set, and electrical substations. Thanks to the improvements implemented—including more efficient equipment with inverters, automatic control of air delivery, and a photovoltaic system of approximately 37 kWp—energy consumption has been reduced, while a carbon offset plan covering 500,000 kg of CO₂ has further minimized the environmental impact. The work was organized so as not to interfere with the plant’s normal operations.