The plant, built in the early 1980s, serves a population of 38,000 Equivalent Inhabitants with around 60% of industrial waste.

Apart from the age, the decree 152/99 requires a significant upgrading work planned in two subsequent steps. The first step is now concluded and the second step works are underway.

On the whole, the project includes:

• new screening system with 3 mm spacing;
• restructuring of sand catcher/separator system;
• restructuring of the activated sludge biologic treatment line with subdivision on two lines in parallel and nitrogen removal;
• fine bubble aeration unit to replace turbines;
• final filtration of effluents;
• ultraviolet disinfection section;
• control of odour emissions;
• new mechanical dehydration unit with high capacity centrifuges;
• exhaust air extraction and treatment;
• renovation of structural works.

All works were scheduled and carried out with no interruption of the water purification service.