The SEMIZENTRAL approach is a smart way to handle the challenges of fast-growing cities with limited resources. By combining water, wastewater, waste, and energy systems, it helps cities use resources more efficiently. In Qingdao, China, a Resource Recovery Center was built to treat greywater and blackwater separately. The treated greywater is reused for flushing toilets, while the reclaimed blackwater is used for irrigation. However, the actual composition of the wastewater was different from what was expected, likely due to user behavior and connections between different types of water. This means that the treatment processes had to be adjusted to meet legal standards. Despite these challenges, the approach shows promise for sustainable urban development.