Study on the Content and Influencing Factors of Groundwater Nitrate Nitrogen in Hebei Province

In order to investigate the content of groundwater NO₃ - N in Hebei Province. [Methods] In 2011,500 groundwater samples were collected from 11 cities of Hebei Province before and after the rainy season, the contents of groundwater NO₃ - N was analyzed with ultraviolet and visible spectrophotometer. [Results] The groundwater NO₃ - N contents of Hebei Province changed from 0.01mg/L to 350.86 mg/L, averaged 9.37mg/L. Single maize seeding in spring and vegetable cropping had the severe effects on groundwater NO₃ - N contents and cotton cropping had the least effect. The groundwater NO₃ - N contents of Hebei Province declined with the increasing depth from where sampled. According to the NO₃ - N contents, the water from deeper than 100m had the best quality, and from shallower than 30m had the worst quality. [Conclusion] According to the national drinking water standard, there was 11% of sample with NO₃ - N contents higher than 20 mg/L. 45.40% of the sample from Hebei Province with the NO₃ - N contents was lower or equal to 2mg/L, which means better quality for drinking water.