Handan, China
Commissioned by Handan Municipal Government, Turenscape has transformed an urban waste dump into a newly designed experiment: a nature-based wastewater remediation system in northeast China.
For this project, several types of constructed wetland were combined to form an immersive living landscape in which the correlations between design variables and ecosystem performance can be observed and quantified, while simultaneously yielding a landscape for exploration and education.
The project showcases how wastewater and land can simultaneously provide clean water, ecosystem benefits and scientific data, as well as beauty.
For decades, the city Handan suffered water shortages and pollution caused by the demands and impact of heavy industry, including steel and coal.
As one part of its green development campaign, the city won the competition to host Hebei Province’s 4th garden expo—the Handan Garden Expo 2020.
Turenscape won the design competition and was commissioned to design the overall landscape, which covers 325 hectares on a site that formerly was primarily used for dumping coal ash, garbage and other solid wastes.
The Wastewater Purification Terraces were designed as one part of this grand show.
Covering an area of 10.4 hectares, the terraces are intended to be a demonstration of the potential power of nature-based solutions for cleaning wastewater and recycling solid waste.
The site is a 20-meter-high mound, made of urban waste and debris, and is adjacent to a degraded wetland of 20 hectares.
A pre-design site survey indicated that there are no hazardous materials on site and therefore no potential health risk for future visitors.
Three types of wetland systems were designed: (1) the free water surface terrace (FWST) system; (2) the subsurface flow terrace (SFT) system; and (3) retention pond systems or oxidation ponds.
Altogether, five combinations of the three wetland types were designed for observation.
The cleansed water is then discharged into the adjacent wetland to help restore the degraded wetland ecosystem.
A network of boardwalks connecting observation points, platforms and pavilions was designed to allow data collection and provide an immersive landscape experience.
First-hand data has been collected that is helping students and professionals understand the natural water-remediation process, and the correlations between design variables and their performance are being analyzed to guide future design practice.
Each day, 15,000 tons of pre-treated wastewater from the local water treatment plant is cleansed.
That is helping to restore the 50-acre adjacent wetland and save 1.0 million KWH of electricity per year compared to conventional water treatment processes.
Meanwhile, an urban dump has been successfully transformed into an immersive living landscape experiment that helps visitors see pollutants (including chloridoid and other uniquely colored minerals) in a visually striking manner.
Project: Design as Experiment: The Handan Wastewater Cleansing Terraces
Landscape Architects: Turenscape Design Institute
Client: Handan Municipal Government
Photographers: Kongian Yu and Jin Zjang
