Lam Kam Tunnel Portal Site for Aquaduct Construction between Tai Po and Butterfly Valley

The project involved the construction of a 12 km long aquaduct by bored tunnelling to transfer water from a major new water treatment facility in the New Territories to Kowloon.

Environmental Concern

There were scattered village houses at a distance of 140 - 250 m away from the tunnel portal. The major environmental concern was the vibration caused by rock blasting at night as well as the noise generated by drilling and blasting works.

Measures Adopted

Quiet Method - A heavy-duty blasting door was constructed at the tunnel portal to achieve a noise reduction of 15 dB(A).

Screening - Noise barriers at the side of residential houses were erected to protect the villagers from construction noise impact.

Administration - Most of the blasting operations were rescheduled to daytime to minimise the noise disturbance at night.

Monitoring - Noise monitoring was conducted by an independent environmental team to audit the construction noise levels at the nearest Noise Sensitive Receiver.

Observations & Achievements

Given the large scale of the tunnelling work as well as the close proximity of the village houses, the potential noise disturbance could be significant. Yet, with the noise-reduction measures including the noise barriers and blasting door, the noise disturbance was effectively kept to a minimal.