A Tale of Two Water Supplies in China: Finding Practical Solutions to Urban and Rural Water Supply Problems.

Access to safe drinking water is among the 17 United Nations sustainable development goals. As the largest developing country, China has confronted large challenges to providing safe and sufficient drinking water to its population of 1.4 billion under the conditions of limited water sources and ubiquitous water contamination. This Account outlines these challenges as well as the practical solutions implemented by Chinese water professionals. We first provide a general introduction of the water supply in China. Next, we describe the main challenges of water source shortages and source water contamination. The practical solutions developed by Chinese water professionals are the core part of this Account, to which we have devoted ourselves to and contributed in some issues and cases. The water supply in China is a binary system that reflects the gap between urban and rural communities. Both urban and rural water supplies have been subject to water source shortages and contamination. Water shortages are mainly solved by long-distance water transportation projects. Urban water utilities generally pay attention to organic matter, ammonia, algae, and chemical spills in source water while also focusing on micro-organisms and disinfection byproducts in tap water. Micro-organisms are a widespread concern for rural water supplies, whereas arsenic, fluoride, and ammonia are an endemic concern in some rural communities. Investment in updating of treatment processes significantly benefits urban water supplies, and advanced treatment of ozonation and biologically activated carbon processes are now commonly used to ensure that strict drinking water quality standards are met. However, this is not the case for rural water supplies, where expensive advanced treatment is not affordable. Thus, improving rural water supplies requires approaches such as searching for sources with better water quality, using automated ultrafiltration instruments, or connecting to urban water supply distribution systems. For rural areas with high concentrations of arsenic or fluoride in source water, specific adsorbents are a practical way to help farmers. Similar challenges will be encountered elsewhere in the world; therefore, the practical solutions applied in China will be useful to other countries in different stages of development.