The aim of this study was to examine chemical and isotopic compositions of groundwater and lake water near an area contaminated by petroleum and to evaluate influence of petroleum on them during the period from March to August 2011. In dry season,
Ca2+ and
SO42− were dominant in the groundwater and lake water and
Ca2+ and
HCO3− were significant in wet season.
δ18O and
δD of the groundwater and lake water were plotted near LMWL (
δD=8.06δ18O+12.5).
δ18O and
δD of the lake water did not show seasonal variation. However,
δ18O and
δD of the groundwater were enriched in wet season compared with those in dry season because of influence of small ponds around wells where evaporation losses were slightly experienced. Redox condition of most lake water was oxidation environment in contact with the atmosphere during the study period. However, redox condition of groundwater was transitional environment in dry season and oxidation environment in wet season because of influence of contaminant such as petroleum. In some groundwater, the concentrations of
NO3− in some groundwater were less than 1 mg/L because of denitrification. Also,
NO3− showed positive correlation with
SO42− and weak negative correlation with
HCO3−, because of influence of denitrification.
Keywords: Petroleum contaminated area;Hydrochemistry;Water quality;Oxygen and hydrogen isotope;Denitrification;