The Guiyang Dagangou Karst Groundwater Seepage Pollution

The Karst groundwater was been polluted by industrial sewage in DaGanGou of GuiYang.The concentrations of the phosphorus and fluorine were high in groundwater,which were beyond dozens to hundreds times in the standard of the three type of surface water and ground water.Through hydrogeological survey, exploration,monitoring in DaGanGou in recent two years,The paper has analyzed the characteristics of the Karst aquifer system,the law of recharge and runoff and excretion of groundwater and dynamic parameters of groundwater in the study area. Based on this analysis,we found the Karst containing water system of MaAnShan～Phosphogypsum Site～W_8—9 was been polluted very seriously by phosphorus and fluorine.The cause of pollution was been found.The pollution sources turned out to be Phosphogypsum Site and old sewage tank.Based on analysis of the physical,chemical and mechanical properties of the Phosphogypsum and leaching test of residual phosphate in Phosphogypsum, leaching model was been established The natural logarithm of the phosphate concentration and liquid-solid ratio presented negative correlation in leachate.The process of residual phosphate released under the rainfall was very slow and lasting, which made groundwater polluted seriously.So the Phosphogypsum Site is a permanent pollution source.Based on hydrogeological investigation and analysis of the Karst leakage and the results of water monitoring,the pollution of Karst groundwater and surface water was evaluated.The results indicated that the groundwater did not suffer the pollution in the north and east of the sit,but in the south and southwest of the sit,the Karst groundwater was direct polluted by the Phosphogypsum Site.The way of leakage pollution is Karst pipeline and fissure.The groundwater pollution presented linear distribution.The direction of Karst leakage pollution is southwest,and the same as the runoff of groundwater.The surface water in DaGanGou and XiFeng river were been polluted by the runoff and excretion of groundwater,which made the river water show ivory white.Polluted water posed a threat to the water quality and aquatic biological environment of WuJiangDu reservoir.The time series analysis method in random model was chosen to simulate the Karst leakage pollution in DaGanGou because the Karst water-bearing media is uneven.The results showed that this model objectively reflect the law of dynamic change of groundwater and a high simulating precision,which would provide a new method for evaluation and forecasting of pollution of Leakage in Karst areasOn this basis,control suggestions for Karst leakage pollution are given,and a scientific basis for solving groundwater the pollution in the areas is provided.