Objective To investigate the pollution status of well water and the correlation between pollution level and the distance from pollutant source, to provide a reference for the drinking water sanitation for villagers.
Methods Cluster sampling method was applied to select 95 water samples from different wells and 6 indices analyzed such as volatile phenol, chloride, etc. Elsewhere, pollutant water samples at different place in a paper mill drains and 3 well water samples at different distance from the paper mill drains were collected and analyzed. At the same time, the correlation between the distance from pollutant source and those 6 indices of the well water samples was analyzed.
Results Volatile phenol in 8.42% well water samples exceeded the National Standard(0.007~0.010 mg/L). Hg content in one well water sample was impermissibly high, the concentration was 0.04 mg/L. The other indices were all meeting the Standard. Volatile phenol content had strong association with the distance from pollutant source, its concentration in well water samples decreased as the distance from pollutant source increased. Its concentration in well water samples of 100 meters away form the paper mill drains was less than 0.002 mg/L, fitting the Standard.
Conclusion Part of well water was polluted by volatile phenol in a town of Sichuan. Wells should be drilled at least 100 m away from paper mill drains. The well water located less than 100 m from the pollutant source was not suitable for drinking.
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