Parks and plants

The Qingshan Sewage Plant, is hard to find－partly because the entrance is hidden among flowers and trees, but mainly because most of the facility is underground. The plant, which covers 2.1 hectares, is directly below a large park dotted with gym equipment and jogging tracks.

Sun Yun visits the park every day to practice tai chi. "In the past, we made a detour around the riverbank to avoid the smell, but now the riverbank is a popular spot for sports lovers," he said.

Opened in 2012, the sewage plant is one of three underground facilities built in the city in recent years. They all use filtering membranes and biotechnology to purify the water, and each is capable of dealing with 50,000 tons of water a day to serve the needs of the 260,000 people in their catchments areas.

"The park's landscape features use river water that is purified at the plant. The cost of building a plant underground is double that of facilities built above ground, but the money made by saving the land for commercial use will offset the construction costs, said Han Yiqin, the director.

Eco-revitalization will improve people's living circumstances and breathe fresh vitality into real estate projects along the river. According to Zhao, new apartments built near his home are priced between 17,000 yuan and 25,000 yuan ($2,569 and $3,778) per square meter, far more than his own residence.