September 2023

Dr. CHUI Ho Kwong, Samuel, JP
Director of Environmental Protection
EIA Ordinance Register Office
Environmental Protection Department

Dear Dr. Chui,
Project Profile for Relocation of Tsuen Wan No. 2 Fresh Water Service Reservoir to Caverns - Investigation, Design and Construction

Green Power would like to draw your kind attention to our comments about the above-captioned Project Profile (PP).

1. Given that the housing estates and public facilities are close to the project site, the anticipated noise impacts should be mitigated by sufficient noise barriers and proper noise management.  Besides, the representatives of the noise sensitive receivers should be well informed about the blasting operation schedule to avoid any unnecessary public panic.

2. The project site is located on a hillside threatened by landslides and flash floods. Given the recent record-breaking rainstorm, the project proponent should avoid excavation works during the rainy season and formulate a contingency plan to cope with the “once-in-a-century” unfavorable weather.

3. Groundwater infiltration may alter the hydraulics and/or hydrology of the natural streams on the ground level resulting in aquatic ecosystem degradation or loss. Apart from probing ahead to assess the groundwater inflow, active monitoring of the existing streams should also be taken place to inform any unusual shrinking of water level during the construction phase.

4. To avoid the invasion of exotic plant species to the nearby Country Parks, native tree species should be selected for the compensatory planting and new tree planting. Post-planting monitoring and maintenance should be included as well.

5. According to the butterfly survey conducted by the Global Change and Tropical Conservation Laboratory of the University of Hong Kong, a large over-wintering butterfly aggregation has stayed at the edge of Kam Shan Country Park (within 1km of the project site) in November 2022. The project proponent should be alert to any sign of butterfly aggregation or migration in the dry season and prepare for adaptive measures, such as temporal work suspension, to minimize human disturbances.

6. Construction and demolition (C&D) materials, chemical wastes, general refuse etc., should be appropriately stored, transported, and finally disposed of at the designated facilities and/or environmentally treated. Unauthorized disposal of solid waste should be strictly prohibited. Deterrent clauses should be incorporated in the work contracts to monitor and penalize fly-tipping activities.

7. Given that the cavern is located in granite bedrock, there is a potential health risk of radioactive radon gas emission. Sufficient ventilation and filtration systems should be installed in the project site to control the radon level in line with the EPD’s ProPECC PN 1/99 Control of Radon Concentration in New Buildings.

Thank you very much for your kind attention. For any inquiries, please contact the undersigned at Green Power (T: 3961 0200, F: 2314 2661, Email:

Yours faithfully,

LO Wing-fung
Senior Education & Conservation Officer
Green Power

Yours faithfully,

LO Wing-fung
Senior Education & Conservation Officer
Green Power