Study On The Environmental Impact Assessment Of Groundwater Of Pangpangta Mine Filed In Shanxi Province

The coal industry is the pillar industry of national economy in China, it has beenattracting wide attention of the society. With the rapid development of national economy,the environmental problems caused by it have gradually become the focus of attention.Coal mining has caused water loss, wetland degradation, land desertification, karst collapse,ground fissures, land subsidence, seawater intrusion and other environmentalhydrogeology geological problems, the problem of eco-environmental and social issues.The influence of coal mining on the groundwater environment can not be ignored.Therefore, the environmental impact assessment of groundwater should be an importantpart of environmental impact assessment in mining area. Forecasting evolution trend ofgroundwater flow field by using numerical simulation is the effective measure to improvethe depth and accuracy of groundwater environmental impact assessment and be favorableto grasp the law of the environmental impact of groundwater in mining area.Pangpangta mine field of Huozhou is located in the middle of hedong coalfield,Shanxi Province. It is a certain representativeness because the groundwater environmentwhere it relates to the Liulin spring-field is a nature reserve and Ordovician limestonewater is the protection target and other sensitive factors. Meanwhile, two coal bedsexploitation, and the greater depth of the western position, will involve two layers coalmining under high pressure. Therefore, take this mine as an example, the paper studys onthe evaluation contents and technical methods for groundwater environmental impactassessment in the coal mining area.The effect of coal mining on groundwater mainly causes changes in groundwater flowfield or groundwater level, so it belongs to Class â…¡ construction project. Area includingindustrial site and coal preparation plant is mainly affect the groundwater quality,belonging to Class I construction item. Therefore, this projrcct is identified as Class IIIbuilding project to evaluate. Considering Class â… and â…¡ characteristics and the division ofevaluation grade of construction projects, the grade of the mine is the first-order of Classâ…¢ in environmental impact assessment of groundwater. Based on the formation lithology combination, the occurrence condition ofgroundwater and hydrodynamic characteristics, the aquifer structure is generalized asunconfined aquifer, relative impermeable layer and confined aquifer, a total of nine layersdownward from the surface. Groundwater system is established as the inhomogeneous andanisotropic, three-dimensional structure and unsteady flow in the simulation area.Hydrogeological parameters, which obtain from repeating parameter adjustment, modelidentification and verification, make the measured values and simulation values ofgroundwater level in good agreement.Coal mining has little effect on the level of phreatic aquifer and no obvious impact onthe dispersion of extraction point of drinking water through the level of phreatic aquiferforecasting. The level of aquifer in Ordovician limestone drops to some extent in theconditions of tmining and without mining, but it is only a little change. So we can beconsidered coal mining will not cause a big impact on the Ordovician limestone aquifer bypredicting.In the abnormal situations or accident conditions, Plume concentration ofcharacteristic factors will exceed the reference standard in a certain period of time.However, it is in a limited area so that it will not influence the groundwater environmentobviously.