8                     WATER QUALITY

 

Introduction

 

8.1                 With proper recommended mitigation measures in place, no adverse water quality is expected during the construction and operation phases. 

 

8.2                 Regular inspections of the construction activities and works areas should be conducted to ensure that the recommended mitigation measures are properly implemented.

 

Monitoring Requirements

 

Construction Phase

 

8.3                 No surface water quality monitoring would be required during the construction phase.  To avoid potential water quality impact arising from construction activities, regular site audit should be conducted to ensure the recommended mitigation measures are properly implemented.

 

8.4                 As recommended in Section 9 of the EIA report, prior to the commencement of any excavation works within the potentially contaminated areas (including the works area at Mai Po, Shek Kong, Lai Chi Kok, Kwai Chung and Nam Cheong), the baseline groundwater quality in these areas should be reviewed based on the collected relevant site investigation data at the EIA stage,  and any additional groundwater quality measurements to be performed with reference to Guidance Note for Contaminated Land Assessment and Remediation.  The review results should be submitted to EPD for examination.  If the review results indicated that the groundwater within works areas is contaminated under Guidance Manual for Use of Risk-Based Remediation Goals for Contaminated Land Management and would be recharged into the ground, the groundwater recharge and groundwater monitoring requirements as described in Appendix C should be followed.

 

8.5                 A detailed groundwater monitoring plan (including the details of monitoring locations and programme, action levels and emergency response) should be developed in detailed design stage and conducted during the construction and post construction stages to monitor any groundwater drawdown at both the proposed tunneling works areas and their adjacent areas.  Details of requirement are provided in Section 2 of this EM&A Manual.

 

Operation Phase

 

8.6                 No adverse water quality impact would be anticipated during the operation phase, provided that all recommended mitigation measures are properly implemented.  Therefore, water quality monitoring and audit is not required during the operation phase.

 

Mitigation Measures

 

8.7                 The recommended mitigation measures for water quality impacts are presented the Implementation Schedule in Appendix A.

 

8.8                 In the event of complaints, or non-compliance / area of improvement being observed, the ET and the Contractor should review the effectiveness of these mitigation measures, design alternative or additional mitigation measures as appropriate and propose to ER for approval, and implement these alternative or additional measures.

 

Audit Requirements

 

8.9                 Implementation of regular site audits is to ensure that the recommended mitigation measures are to be properly undertaken during construction phase of the Project. It can also provide an effective control of any malpractices and therefore achieve continual improvement of environmental performance on site.  Site audits should include site inspections and compliance audits.

Site Inspection

 

8.10             Inspections of the construction activities and works areas should be conducted at least weekly to ensure that the recommended mitigation measures are properly implemented.

 

8.11             Site audits should be carried out by the ET and should be based on the mitigation measures for water pollution control recommended in Appendix A.  In the event that the recommended mitigation measures are not fully or properly implemented, deficiency should be recorded and reported to the site management.  Suitable actions are to be carried out to:

 

§         investigate the problems and the causes;

§         issue action notes to the Contractor who is responsible for the works;

§         implement remedial and corrective actions immediately;

§         re-inspect the site conditions upon completion of the remedial and corrective actions; and

§         record the event and discuss with the Contractor for preventive actions.

 

Compliance Audits

 

8.12             Compliance audits are to be undertaken to ensure that a valid discharge license has been issued by EPD prior to the discharge of effluent from the construction activities of the Project site. If monitoring of the treated effluent quality from the works areas is required during the construction phase of the Project, the monitoring should be carried out in accordance with the Water Pollution Control Ordinance (WPCO) license which is under the ambit of regional office (RO) of EPD. The audit results reflect whether the effluent quality is in compliance with the discharge license requirements. In case of non-compliance, suitable actions by the ET should be undertaken to:

 

§         Notify the Contractor, IEC and ER;

§         Identify the sources of pollution;

§         Check the implementation status of the recommended mitigation measures;

§         Investigate the operating conditions of the on-site treatment systems;

§         Implement corrective and remedial actions to improve the effluent quality;

§         Increase monitoring frequency until the effluent quality is in compliance with the discharge licence requirements; and

§         Record the non-compliance and propose preventive measures.