The local groundwater quality behind the curtain-grouting was abnormal, with a low pH value and a high content of HCO~-_3, which resulted from the oxidation of organic substances contained in LW chemical materials, furthermore we found some organic substance occurring in the elutes; 幕后局部地下水的pH值低于坝前库水,且含有较高的HCO-3,为水溶液中含有源于化灌材料的有机质的氧化所致;