Preliminary conceptual study on impact of land reclamation on groundwater flow and contaminant migration in Penny ’ s Bay

A large-scale land reclamation project is now being carried out at Penny's Bay, Lantau Island, Hong Kong. The completed reclamation will provide 2.8 km 2 of land for the construction of the new Hong Kong Disneyland and other essential infrastructure developments. The impact of this project on various aspects such as ecology and environment has been widely discussed. This paper studies the change of groundwater system around the bay area in response to the land reclamation. This paper also predicts the possible pathway of the contaminated groundwater due to Cheoy Lee Shipyard, which was located on the north and eastern shores of Penny's Bay and had operated for almost 40 years. Some findings are observed on basis of the preliminary study. 1) After reclamation the total groundwater head in the entire model area is increased and the slopes immediately behind the original coast of the Bay have the most significant buildup in total head. 2) The seepage along the coastlines beyond Penny's Bay will be increased in response to the reclamation and along Yam O Wan the seepage is increased most significantly. 3) If the contaminated soil near Cheoy Lee Shipyard is not removed, the contaminated groundwater will not spread out much within Penny's Bay but will migrate northeast toward Yam O Wan. FEMWATER, a three-dimensional finite element ground water model, is used in this study. It should be noted that this paper is entirely based on desk computer simulation and all the basic data such as aquifer properties and infiltration coefficient are assumed values. The overall qualitative conclusions of the study are believed to be reasonable but quantitative values of the computer output such as groundwater head or contaminant travel time may be very uncertain due to lack of actual data and field hydrogeological study from this reclamation site.