Groundwater is under the dual threat of pollution and over-mining
In January 2016, the ministry of water resources announced that in January 2016, groundwater in China was generally "poor quality". Specific terms, in 2015, ministry of water resources distribution in songliao plain, the plain, in Shanxi Province and northwest basin and plain, 2103 eyes of jianghan plain groundwater Wells were monitored, monitoring results show that: the IV class water 691, accounting for 32.9%; V class water 994, accounting for 47.3%, the combined ratio of the two is 80.2%.
It is worth noting that the type IV water is mainly applicable to the general industrial water area and the recreational water area which is not directly exposed to human body. It is not suitable for human consumption, and V water pollution is even more serious. This also means that more than 80 percent of the groundwater is threatened by pollution. The pollution of "three nitrogen" in the main pollution index is heavier, and some areas have some degree of heavy metal and toxic organic pollutants. At the same time, groundwater has been seriously threatened. In January 2016, groundwater storage in the main areas of the country was 8.24 billion cubic meters lower than the same period last year (about 8.24 billion tons).
Mostly shallow groundwater
In the Yangtze river, Yellow River, huai river, haihe river and songliao, pollution and overharvesting are becoming the main threats to the waters of the river basin. Ministry of water resources of the groundwater monitoring, basic covers the development and utilization of groundwater level monitoring scope is larger, and serious pollution, give priority to with shallow groundwater monitoring objects, easily influenced by the surface or soil infiltration water pollution, poor water quality evaluation results overall.
The results of water quality evaluation of 2103 eyes water Wells showed that there were 418 types of water without type I, and 418 in class II to III, accounting for 19.9% of the total. Class IV water 691, accounting for 32.9%; V type water 994, accounting for 47.3%. Among them, the major pollution indicators in addition to the total hardness, manganese, iron, and fluoride may be due to the hydrological and geochemical background monitoring values on the high side, "three nitrogen" pollution is heavier, parts there is a certain degree of heavy metals and toxic organic pollutants. Nationwide monitoring, it is according to the published in 2011 the national ground water pollution control planning (2011-2020) of the deployment, for understanding the "base" of the groundwater pollution, the plan put forward by the year 2015 to basic grasp of groundwater pollution.
"IV water is not suitable for human consumption, and V water pollution is even more serious. In fact, these two types of water are not very good for human contact." "It is not particularly surprising that this figure is 80 percent from the monitoring of the basin and the monitoring objects," ma jun, director of the center for public and environmental studies, told reporters. The heavy metals and toxic organic pollutants are contaminated by the shallow groundwater that flows through the city, which is more vulnerable to agricultural sources, industrial waste and landfill pollution. It is worth noting that the pollution of shallow ground water has "mutual influence" with surface water pollution. Ma jun pointed out that "the results of the main monitoring objects in shallow groundwater also indicate that there is a corresponding pollution of surface water in the basin. During the dry season, shallow ground water will supply the surface water. Similarly, groundwater supplies come from surface water.
Pollution, over-mining threat "water security"
Groundwater is contaminated or has serious "water security" problems. According to statistics from the ministry of land and resources, more than 400 of the country's 657 cities now use groundwater as a source of drinking water. Nationwide, nearly 70 percent of the population drinks groundwater.
As high as 80 percent of groundwater pollution monitoring results, will it affect the safety of residents drinking water?
"In general, deep groundwater is used as a source of drinking water, and deep groundwater is not easily contaminated." "But there are still many rural residents drinking shallow groundwater, and the pollution will have a major impact on them," ma said. It is worth mentioning that in addition to the problem of pollution, overmining is also a great threat to the "water security" in China.
In January 2016, the main investigation on groundwater reserves of 8.24 billion cubic meters of less than the same period last year, single reduces 4.92 billion cubic meters, plain and headed by the storage capacity of groundwater in hebei reduce: a year, 2.21 billion cubic meters of groundwater in hebei area. Ma jun said, "for groundwater management, the cost more than management of surface water and groundwater pollution is relatively complex, and the development exploitation in above quota of groundwater, will also bring a rift, collapse and other secondary disasters."
