Cause of Impact
Potential air quality impacts from the construction works for the Project would mainly be due to construction dust, which would be anticipated to be generated from activities, such as soil excavation, backfilling, wind erosion, transportation/handling of C&D materials, rock crushing facilities, etc.
No operational air quality impact at ASRs is envisaged for the area.
In order to minimize air dust levels during the construction, the following remedies will be applied:
- Regular watering to reduce dust emissions from exposed site surfaces and unpaved roads, particularly during dry weather;
- The rock crushing facility would be enclosed and a fabric baghouse/cartridge filter type dust extraction and collection system would be installed;
- Tarpaulin covers would be provided on wire mesh covered steel cages to contain the dust generated by blasting at HOM Station, and all dusty vehicle loads transported to, from and between site locations;
- Side enclosure and covering of any aggregate or dusty material storage piles to reduce emissions. Where this is not practicable owing to frequent usage, watering shall be applied to aggregate fines;
- Open stockpiles shall be avoided or covered. Where possible, prevent placing dusty material storage piles near ASRs;
- Establishment and use of vehicle wheel and body washing facilities at the exit points of the site;
- Imposition of speed controls for vehicles on unpaved site roads, 8 km per hour is the recommended limit;
- Where possible, routing of vehicles and position of construction plant should be at the maximum possible distance from ASRs;
- Every stock of more than 20 bags of cement or dry pulverised fuel ash (PFA) should be covered entirely by impervious sheeting or placed in an area sheltered on the top and the 3 sides;
- Cement or dry PFA delivered in bulk should be stored in a closed silo fitted with an audible high level alarm which is interlocked with the material filling line and no overfilling is allowed; and
- Loading, unloading, transfer, handling or storage of bulk cement or dry PFA should be carried out in a totally enclosed system or facility, and any vent or exhaust should be fitted with an effective fabric filter or equivalent air pollution control system.
With the implementation of mitigation measures in the Air Pollution Control (Construction Dust) Regulation, proposed dust suppression measures, and good site practices, no adverse dust impacts on the ASRs would be anticipated anticipated for the 1-hour and 24-hour average of TSP concentration. However, there are exceedances near Hung Hom Finger Pier Barging Point for the cumulative annual average TSP concentration (click here to see the results). However, the exceedances are marginal, short-term and in most cases transient and based upon worst case assumptions. In addition, based on the trend of the background TSP levels being recorded at the EPD monitoring station, it is reasonable to assume that when construction of KTE project commences in 2011, the TSP levels could be lower and compliance with AQO.