Nitrate Contamination of Drinking Water and its Influencing Factors of a County in Hebei Province

Objectives  To explore the nitrate contamination of drinking water and its influencing factors in a county of Hebei Province.

Methods  Eighty survey spots were selected by stratified random sampling method, and 160 water samples were collected and tested both in dry season and wet season.

Results  The concentration of nitrate in drinking water was 6.02~40.91 mg/L in dry season and 3.17~39.82 mg/L in wet season; and the exceeding standard rates for nitrate in drinking water were 28.75% and 22.50% in dry and wet seasons respectively. The highest exceeding standard rate for nitrate in water samples was in Shangzhai town, the next high rate was in Bailuquan town, and all water samples from Shangzhuang town were qualified. The concentration of nitrate in groundwater from farming areas was the highest, and that from villages was the next. The concentration of nitrate in groundwater was declined with the increase of the depth of water source; and the concentration of nitrate decreased to 11.57 mg/L in groundwater from wells deeper than 200 meters. Pollution around the well was the source of nitrate in groundwater.

Conclusions  Drinking water was seriously polluted by nitrate in the county, which indicated that some measures should be taken to control the pollution of nitrogen-containing organic substances in key areas.