The Quality of Source Water and Tap Water from a District of G City

Objective: To detect the quality of source water and tap water from a district of G city,to provide the evidences for water safety evaluation and water source protection. Methods: The source water and tap water from the district were collected. According to the Standard detection methods for drinking GB / T5750- 2006),the water quality was detected with the methods of chemical method,microbiological method,inductively coupled plasma mass spectrometry,and organic compounds in the water were examined with solid phase exaction and gas chromatography-mass spectrometry. The qualified rates of source water and pipeline water were compared. Results: A total of 118 source water samples and 118 tap water samples were detected. The qualified rates of them were 75. 42% and 83. 90% respectively. There was no statistically significant difference( P 0. 05). The pH value,total hardness,nitrate,total bacteria,total coliforms,manganese,iron,copper,zinc,and arsenic were under the limit value of the standard. The unqualified indicators of source water were chroma,turbidity,oxygen consumption,selenium and lead. For the tap water,the unqualified indicators were oxygen consumption,selenium and lead. 10 organic pollutants were found in the source water,and 12 organic pollutants were found in the tap water. The highest values of di( 2-ethylhexyl) phthalate( DEHP) and dibutyl phthalate( DBP) in source water( 0. 019 6 mg / L and 0. 004 8 mg / L respectively) and tap water( 0. 018 4 mg / L and 0. 004 2 mg / L,respectively) were above the limited value of the standard,the levels of other organic pollutants were under the limit value. Conclusions: The drinking water of this district is polluted by lead,selenium and organic pollutants and need to improve.