title: Nitrate and ammonia contaminations in drinking water and the affecting factors in Hailun, northeast China.
abstract: Drinking water samples (N = 228) from domestic tube wells (DTWs) and seven samples from public water supply wells (PWSWs) were collected and tested in Hailun, northeast China. The percentage of samples with nitrate and ammonia concentrations above the maximum acceptable concentration of nitrate, 10 mg N/L, and the maximum ensure concentration of ammonia, 1.5 mg/L, for the DTWs were significantly higher than for the PWSWs. Of the DTWs, an important observation was that the occurrence of groundwater nitrate contamination was directly related to well tube material with different joint pathways. Nitrate in seamless-tube wells was lower statistically significantly than those in multiple-section-tube wells (p < .001). Furthermore, well depth and hydrogeological setting might have some impacts on nitrogen contamination and the major sources of inorganic nitrogen contamination may be nitrogenous chemical fertilizer. Therefore, PWSWs built for all families are the best way to ensure the drinking water safety in villages. For DTWs it is necessary to use seamless tubes and to dig deep enough according to the depth of groundwater level. Improving the efficiency of chemical fertilizer use would also reduce the risk of groundwater contamination.
authors.affiliation: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, People's Republic of China.
authors.forename: Xinfeng
authors.initials: X
authors.lastname: Zhao
authors.forename: Liding
authors.initials: L
authors.lastname: Chen
authors.forename: Haiping
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000641:Ammonia / Q000032:analysis*; D002681:China; D060766:Drinking Water / Q000737:chemistry*; D006801:Humans; D008452:Maximum Allowable Concentration; D009566:Nitrates / Q000032:analysis*; D012307:Risk Factors; D012423:Rural Health; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply; D060986:Water Wells / Q000737:chemistry*
chemical_list: D060766:Drinking Water; D009566:Nitrates; D014874:Water Pollutants, Chemical; D000641:Ammonia