Strategic Sewage Disposal Scheme, Kwun Tong Riser Shaft

This project involved the construction of two tunnels to Kwun Tong, from Chai Wan and Tseung Kwan O respectively. The construction site of the Kwun Tong Riser Shaft was situated in New Wai Yip Street near Laguna City, Cha Kwo Ling.

Environmental Concern

The works was around 140 m away from residential buildings at Laguna City. Construction noise caused by the use of powered machinery for concrete pouring during night-time was the major concern of the residents.

Measures Adopted

Shielding - An acoustic shield with sound absorptive lining was erected to screen the concrete pouring area from the noise sensitive receivers. Similar acoustic shield was also provided to screen other stationary powered machinery.

Administration - The access road where the concrete lorry mixers entered was screened from the noise sensitive receivers.

Monitoring - Noise monitoring was conducted by an independent environmental team to monitor the daytime and night-time construction noise levels and to ensure the effectiveness of the mitigation measures.

Observations & Achievements

For this project, a large quantity of concrete was continuously required to be poured without interruption. It was also necessary to provide ventilation whenever works were being carried out inside the underground tunnels.

Through erecting the acoustic shield, noise impact on the dwellings was much reduced. Other administrative noise control measures were also implemented to further reduce the construction noise impact.