9.1
In accordance with the EM&A Manual, monitoring of
landfill gas is required for construction works within the Sai Tso Wan Landfill
Consultation Zone during the construction phase. This section presents the
results of landfill gas measurements performed by the Contractor. Appendix
A shows the Limit Levels for the monitoring works.
9.2
The “Landfill Gas Monitoring Proposal”, including the
monitoring programme and detailed actions, is submitted to the EPD for approval. Details of monitoring in this Proposal is in line
with the monitoring requirements stipulated in the EM&A Manual.
Monitoring Parameters and Frequency
9.3
Monitoring parameters for
Landfill gas monitoring include Methane, Carbon dioxide and Oxygen.
9.4
According to the implementation schedule and recommended
mitigation measures of the EM&A Manual, measurements of the following
frequencies should be carried out:
Excavations deeper than 1m
Ÿ
at the ground surface
before excavation commences;-
Ÿ
immediately before any
worker enters the excavation;
Ÿ
at the beginning of each
working day for the entire period the excavation remains open; and
Ÿ
periodically throughout the
working day whilst workers are in the excavation.
Excavations between 300mm and 1m deep
Ÿ
directly after the
excavation has been completed; and
Ÿ
periodically whilst the
excavation remains open.
For excavations less than 300mm deep
Ÿ
monitoring may be omitted,
at the discretion of the Safety Officer or other appropriately qualified person
9.5
Monitoring of oxygen,
methane and carbon dioxide was performed for excavations at 1m depth or more
within the Consultation Zone. In
this reporting month, the area required to be monitored for landfill gas are shown
below and Figure 6 shows the
landfill gas monitoring locations.
Ø
Excavation Locations: Portion
III
Ø
Manholes and Chambers: N/A
Ø
Relocation of monitoring
wells: N/A
Ø
Any other Confined Spaces: N/A
9.6
Table 9.1 summarizes the equipment
employed by the Contractor for the landfill gas monitoring.
Table 9.1 Landfill Gas Monitoring Equipment
|
Equipment |
Model and Make |
Quantity |
|
Intrinsically safe, portable gas detector |
Crowcon Tetra Portable Gas Detector (Serial No. 100486262/01-020) |
1 |
9.7
In the reporting month,
landfill gas monitoring was carried out by the Contractor at the aforesaid
locations on 52 occasions. No Limit
Level exceedance for landfill gas monitoring was recorded in the reporting
month. The monitoring results are provided in Appendix R. Copies of calibration certificates are attached in Appendix
B.