Castel San Pietro plant maintains operations and improves water quality during renovation

The wastewater treatment plant in Castel San Pietro, Italy, was facing a potential service interruption. One of the plant’s treatment lines was damaged – the concrete was worn out and had to be completely restored. To continue servicing the community during the heavy maintenance work, the plant opted to use the Taron activated sludge filter.

This innovative filtration technology not only enabled the plant to continue operations at full capacity, but also provided an improved effluent quality, benefiting downstream irrigation users.

Investing in Bologna’s water infrastructure

The Castel San Pietro Terme wastewater treatment plant in Bologna recently underwent a significant maintenance upgrade. This complex project, made possible by a 250,000-euro investment by the Hera Group, was executed without any disruption to the surrounding community or businesses.

To keep the plant running during the upgrade, a cutting-edge temporary system was installed in place of a faulty line. The temporary system not only maintained continuous wastewater treatment but also enhanced the quality of treated water.

This improvement was especially beneficial during the warmer months, as the filtrate produced could be recycled and utilized for irrigation.

The project, which began in April of 2024 and was completed in June, is part of a substantial investment plan. Hera Group has committed 2.1 billion euros by 2027, of which 1.2 billion euros are allocated to the integrated water cycle. This investment aims to enhance the resilience and digitalization of the region’s infrastructure and establish it as a leader in service quality.

Maintaining wastewater operations during renovations

The Castel San Pietro wastewater treatment plant is a medium-sized traditional activated sludge plant servicing a population of 25,000. Flows are almost completely managed by automation, with alternating cycles that offer a very high treatment quality, especially in summer periods when the compliance standards increase.

The treatment plant was constructed in the mid-1980s and expanded between 2005 and 2006. Supported by The Hera Group’s investment, the multi-utility began the maintenance effort to restore the concrete of one of the treatment lines, which had worn away over the years and was impacting plant operations.

The Hera Group evaluated different solutions on the market and decided to rent the Sanitaire Taron, an activated sludge filter with space-saving technology specifically designed for activated sludge systems.

The rental solution kept the plant operational during the line upgrade and enabled the production of high-quality effluent, exceeding the regulatory standards that the plant met previously. Once the renovation work was completed, the temporary filtration systems were decommissioned.

Castel San Pietro supports irrigation with treated recycled water

"The Castel San Pietro purification plant is a vital facility for the Castel San Pietro area,” says Paolo Gelli, Hera Group Water Operations Manager for the Bologna area. “Improving such an important structure has required a substantial investment and a thoughtful selection process to identify the best solution.”

“Xylem has supported our community by keeping the treatment plant operational while guaranteeing the high-water quality standards required for irrigation during the warm months of the year.”

The Castel San Pietro plant recycles nearly 1 million cubic meters of treated wastewater annually to the canal and accumulation reservoir located downstream, supporting the irrigation uses of an area reliant on agriculture but at risk of water scarcity due to a lack of traditional surface water sources.

Learn more about the Sanitaire Taron activated sludge filter

The Taron™ activated sludge filter is an innovative technology that simplifies wastewater treatment processes and reduces space requirements by replacing traditional secondary clarification and tertiary filtration while maintaining similar effluent quality. It can also operate alongside secondary clarifiers to enhance effluent quality and increase biological treatment capacity in aging wastewater treatment facilities, easing the load of hydraulic and suspended solids on secondary clarification.

The Taron activated sludge filter effectively reduces total phosphorus (TP) and total nitrogen (TN), providing a cost-effective treatment solution that minimizes the need for new civil construction and allows for the repurposing of existing infrastructure during plant upgrades.

About HERA

Hera S.p.A is leading multiutility company based in Bologna, Italy, active in the distribution of gas, water, energy, and waste disposal. Founded in 2002 and listed on the Italian stock exchange in 2003, Hera has made its direct relationship with the territory a real asset that has improved its resilience and ability to drive change in the ecological transition, circular economy and innovation, meeting the needs of 4.2 million citizens in 311 municipalities located in the central north Italy.