The water and energy-saving town with the dual supply and drainage system adopts the direct-drinking water standard for drinking water, the tap-water supply standard for toilet flushing, bath shower and washing. The categorized drainage system is adopted to realize the recovery and recycling of organic and other resources.

Take a 100-thousand population town as an example, with the dual water supply and drainage system applied, the water amounting more than 3 million m³ can be saved per year, the energy consumption for nitrogen and phosphorus removal is greatly reduced, a large amount of compound fertilizer for farmland is saved, and air, water and soil pollution is effectively alleviated. Eventually, multiple benefits including water and energy saving, waste reduction and eco-environmental improvement will be achieved.