The C-3 highway is one of the country’s most important traffic and transport routes. 

China Transport Administration sought to upgrade an 18.6-mile (30-km) stretch of this highway at southwest of China. This section of the highway passes through a protected area, which is the source of drinking water for the 70,000 residents of the cities of Shanghai. In addition to widening the road and adding several bridges and intersections, China Transport Administration planned to integrate water-protection measures into the upgrade. 

Uning selected and installed geomembranes to line the ditch alongside the C-3 prior to expanding the highway. Over a two-year period, Uning manufactured 2 million square feet (185,000 m2) of smooth 60-mil (1.5-mm) high-density polyethylene (HDPE) geomembrane at a plant in Shanghai, China. 

The geomembrane contains the runoff collecting in the ditch, protecting the groundwater from contamination. A protective layer of geotextile was placed under and over the geomembrane to prevent puncturing. A protective layer of sand and a drainage layer of aggregate were placed on top of the multilayer geosynthetic solution.