Groundwater quality in nearly 60 percent of monitoring sites in 198 cities has been measured as poor, according to a report released by the Ministry of Land and Resources Saturday.



Among a total of nearly 5,000 monitoring sites in these cities, some 40 percent of them have groundwater of poor quality, while it is extremely poor in nearly 17 percent of them, said the report.



Comparing previous monitoring results, the comprehensive quality of groundwater remains stable, with the frequency of poor quality groundwater at above 55 percent for the third year running.



A senior official from the Ministry of Environmental Protection, Wu Xiaoqing, said at a press conference in June last year that among 4,727 groundwater monitoring sites in 200 cities, the water quality of 45 percent has been excellent, good or relatively good, but that the other 55 percent has been poor or very poor, the Xinhua News Agency reported.



Some 60 percent of cities rely on groundwater to supply their demand, Ma Jun, the director of a Beijing-based non-government organization, Institute of Public & Environmental Affairs (IPE), told the Global Times, adding that in arid areas of northern China, it is common for farmers to irrigate their fields using shallow water sources, which are more prone to pollution than deep aquifers.



"Besides drinking water that mainly comes from deep aquifers, groundwater of poor quality used for poultry breeding or irrigation poses problems for food safety and human health," said Ma.



"Some people from the countryside even drink directly from shallow groundwater sources."



Among the factors resulting in polluted groundwater, Ma highlighted industrial effluent and inappropriate waste disposal, explaining that factories dig pits where the content seep underground and remain undetected.



Landfills are also used, where no prevention means are taken to avoid ground and water contamination.



"To improve the quality of groundwater once it is polluted is very difficult," Ma said. "The recovery mainly relies on a natural cycle, which takes dozens of years. Controlling the source of pollution is the most urgent step right now."



Ma said precedents from overseas on protecting groundwater are worth learning from. For example, holding companies contaminating water accountable and making them pay for the recovery will make them more cautious in future.



Tainted groundwater caused a stir in February, when news stories came out of a factory whose untreated sewage was drained straight into wells in Weifang, Shandong Province.



This was denied by local officials but the issue put groundwater pollution back on the map.



Zhao Zhangyuan, a researcher with the Chinese Research Academy of Environmental Sciences, told the Global Times that the current severe situation originated from a long-standing lack of supervision by authorities.



In March, the State Council approved a government work plan on groundwater contamination control, aiming to improve groundwater quality and pollution monitoring as well as launch model projects on groundwater pollution treatment and recovery by the end of 2020, Xinhua reported.