I refer to the letter from Brett Graham headlined, 'Question still not answered' (South China Morning Post, June 18).

We would like to thank Mr Graham for giving us information about road excavation works carried out by utility undertakers in Tai Mong Tsai. However, this does not imply that the Highways Department has no control over utility works along public roads.

We control excavation works on public roads through a permit system. According to the Crown Land Ordinance, a utility undertaker has to obtain an excavation permit from the Highways Department before he can carry out any excavation work on a public road. In issuing an excavation permit we impose permit conditions which stipulate how the excavation works should be carried out. The government works departments also need to obtain excavation permits before carrying out excavation works.