Land reclamation undertaken continuously in Tokyo Bay since the Edo era can be regarded as important for advancing civil engineering projects in Tokyo. Haneda airport D-runway extension work (hereafter D-runway construction) was completed in October 2010, with a new 2,500 m runway, operating a 24-h service, built in a sea area having a water depth of 15-20 m. Part of the island airport was constructed with a pier structure to provide flood control for the Tama River and preserve the environment. This report summarizes the marine geological survey, environmental assessment, and groundwater management for D-runway construction on the basis of previous reports. The main characteristics of construction are: marine drilling was carried out about every 500m in the sea area for the marine geological survey; the effects of construction on ocean currents, bottom sediments, and submarine topography were considered in the environment impact assessment of land reclamation; and, a new underground station was constructed with groundwater control provided by a deep-well dewatering system without building a sealing body for groundwater.
