Investigation and evaluation on nitrate pollution in groundwater of Shunyi District

Nitrate content in groundwater of Shunyi District have been investigated from 1999 to 2000. Three types of groundwater were defined based on the depth and utilization of well, that is drinking well(DW)about 70～150m, irrigation well(IW)about 70～120m and hand pumped well(HW)about 6～20m. It is shown that the nitrate content in groundwater is negatively relative to the depth of well, i.e. 2.54mg/L for DW, 2.05mg/L for IW and 8.39mg/L for HW,and there is none of DW in which nitrate content is above 10mg/L, but 7.4 % of IW and 36.8% of HW is above 10mg/L, unsuitable for drinking. Except for IW, the groundwater of Shunyi District is well in general. Its also shown that the quality of groundwater in vegetable field is inferior to that of crop field, which can be attributed to super input of nitrogen fertilizer in vegetable production.