The Sobreiras Compressed Air Plant, inaugurated in 1904, was the central element of Porto's first sanitation network, the first separate network in Portugal, incorporating pioneering solutions for the time. Powered by steam, it produced compressed air that fed the Shöne ejectors, allowing sewage to be lifted and expelled into the sea. It was decommissioned in 2001, when the Sobreiras Wastewater Treatment Plant was built.
