The deformation of aquitard is the main contribution to land subsidence in the North China Plain, and the water released from aquitard compaction may be a large portion of the exploited groundwater. In this study, the consolidation test was employed to understand the mechanics on the drainage and deformation of aquitard. The results suggested the strain of aquitard mainly resulted from the difference of hydraulic head between aquifers. And it was decreased with depth of aquitard at the same hydrodynamic pressure. In contrast with the interbed within aquifers, the aquitard was deformable when it was compressed. The weakly bound water was significantly released when the void ratio was about 0.44–0.45, and the EC of water released from the aquitard was decreased with the compacting process. The data from the consolidation test suggested that the pumping of groundwater from aquifer III might be less contribution to the land subsidence with respect to other aquifers in the future.
