Heavy Metals in Deep Seated Groundwater in Northern Anhui Province, China: Quality and Background

Forty-five deep seated groundwater samples from three aquifers in two coal mines (Wolonghu and Baishan), northern Anhui Province, China have been measured for four kinds of heavy metal (Pb, Zn, Cr and Ni) concentrations for evaluation of quality and, establishment of environmental background values by using model based objective methods. The results suggest that these groundwater samples are of excellent quality relative to the quality standard of groundwater established by Chinese government, and most of them can be used for drinking directly according to their low concentrations of heavy metals. Moreover, they are considered to be representative of "pristine" state because they are far away from anthropogenic contribution and therefore, they can be used for environmental background estimation. The thresholds of Pb, Zn, Cr and Ni between natural and abnormal or anthropogenic are calculated to be 17.4, 64.9, 3.9 and 71.1μg/L by using model based objective methods, respectively.