Appendix G – Construction Phase Mitigation Measures and their Implementation (Gas Pipeline)

EP-071/2000/C

EM&A Log Ref.

Mitigation Measures

Implemen-tation Status

 

 

Air Quality

 

 

Q1

For the fuel gas supply system, equipment shall be chosen and measures taken, so as to prevent CH4 leakage from the system. In accordance with this recommendation, HEC shall be implementing the following:

 

·          corrosion-preventing coatings on the pipeline;

C

·          welded pipe joints; and

C

·          laying of pipeline below sea bed such that it is well protected from potential damages by marine activities.

C

 

Q2

HEC shall submit to EPD for review, a report of the above actions.

C

 

 

Water Quality

 

3.8

R1

The following rates of dredging for the trenches at the Shenzhen and Lamma approaches and the rate of progress of the jetting shall be adopted:

 

·          a single small grab dredger with a maximum daily rate of working of 2,400m3

NA

·          maximum forward speed of the jetting machine shall be 7 m per minute

C

 

R2

No further mitigation measures were considered necessary, however if unacceptable impacts were to be found in the course of the EM&A programme for the pipeline jetting, then the following measures shall be implemented:

 

·          reducing the speed of the water jetting machine; and

NA

·          temporary suspension of the works.

NA

3.10

 

Pipeline jetting shall only be carried out in the open sea which is far away from sensitive receivers as recommended in the application document for variation of an environmental permit (the Application VEP-174/2005) and indicated in the Figure C1 at the Appendix C of the Permit during the initial jetting operation. Water quality monitoring shall be conducted during the pipeline jetting.

C

 

 

MARINE ECOLOGICAL IMPACTS

 

3.9

S1

To avoid disruption to the Neophocaena phocaenoides (finless porpoise) population in the southwestern coastal waters of Lamma Island, pipeline jetting works located off the coast of southwest Lamma shall not be carried out during spring time from March to May.

C

 

 

hAZARDS

 

 

T1

Detail quantitative risk study shall be conducted in accordance with the requirements in the Gas Safety Ordinance (Cap.51) to satisfy EMSD’s requirements which shall ensure adequate design of the pipeline to protect against third party damage and safe operation of the pipeline system.

C

 

T2

HEC shall review their existing safety management system against current best practice.

C

 

Remarks:

C          -           Compliance with mitigation measure

NC        -           Non-compliance with mitigation measure

N/A       -           Not Applicable