CONTRACT NO: SD 6/2020   Construction of San Shek Wan Sewage Treatment Works, Associated Submarine Outfall and Pui O Sewerage Works   Under Environmental Permit no. EP-538/2017   quarterly Environmental Monitoring & Audit summary Report   November 2022 to January 2023 Revision 3

Table of contents

 

1      Introduction.. 6

1.1.......... Scope of the Report 6

1.2.......... Structure of the Report 6

2.     Basic Project Information.. 8

2.1.......... Project Organization and Key Contact Personnel 8

2.2.......... Construction Programme. 8

3.     A Brief Summary of EM&A Requirements. 10

3.1.......... Monitoring Parameters. 10

3.2.......... Environmental Quality Performance Limits. 10

4.     Implementation Status. 13

4.1.......... Advice on the implementation status of environmental protection and pollution control/mitigation measures. 13

4.2.......... Environmental Mitigation Measures. 13

4.3.......... Environmental monitoring requirements and contractual requirements. 13

5.     Monitoring Results Analysis. 15

5.1.......... Noise Monitoring. 15

5.2.......... Water Quality Monitoring. 15

5.3            Ecological Impact Monitoring……………………………………………..16

5.4.......... Waste Management 16

6.     Complaints, Notification of Summons and Prosecution.. 18

7.     Comments and Recommendations. 20

8.     Conclusion.. 22

lIST OF TABLES

 

Table 2.1       Contact Details of Key Personnel

Table 4.1       Summary of submission status under EP-538/2017

Table 4.2       Summary of the current status on licences and/or permits on environmental protection pertinent to the Project

Table 5.1       Summary of Quantities of Waste Material (November, December 2022 and January 2023)

Table 6.1  Summary of Complaints

Table 6.2       Cumulative Statistics on Complaints

Table 6.3       Cumulative Statistics on Successful Prosecutions

Table 7.1       Construction Activities in Past 3 Months

 

 

lIST OF FIGUREs

 

Figure 2.1    Project Organization Chart

Figure 2.2    Master Layout Plan

Figure 5.1   Locations of Noise Monitoring Station

Figure 5.2   Locations of Water Quality Monitoring Stations

 

 

lIST OF APPENDIces

 

Appendix 5.1    Noise Monitoring Graphical Presentations

Appendix 5.2   Marine Water Quality Monitoring Graphical and Summary of Exceedance Presentations

Appendix 5.3    Quarterly Summary Waste Flow Table

 

 

EXECUTIVE SUMMARY

       i.        This is the Quarterly Environmental Monitoring and Audit (EM&A) Summary Report – November 2022 to January 2023 of Outlying Islands Sewerage Stage 2 – South Lantau Sewerage Works under Environmental Permit no. EP-538/2017 (Hereafter as “the Project”).  The construction works of the Project was commenced on 3 November 2021 and the tentative completion date is Q1 2026.  The Quarterly EM&A Summary Report presents the environmental monitoring findings and information recorded during the period of 01 November 2022 to 31 January 2023.  

 

      ii.        In the reporting period, the principal work activities conducted are as follow:

 

Exceedances of Action/Limit Levels

Noise Monitoring

     iii.        Noise monitoring was conducted at eight (8) noise monitoring stations (N12a, N12b, N13, N14, N15b, N16a, N16b and N17) once per week in the reporting period.

     iv.        School examination was taken place at N17 – Bui O Public School from 14 to 16 November 2022 in the reporting period, the limit level shall be adjusted to 65dB(A) during this period.

      v.        No action and limit level exceedances were recorded in construction noise level in the reporting period.

Water Quality Monitoring

     vi.        Marine-based construction works commenced on 19 April 2022. Water quality monitoring was conducted at nine (9) monitoring stations (seven impact & two control stations) three days per week in the reporting period starting from 12 April 2022. HDD casing works commenced on 30 May 2022.

    vii.        Water quality monitoring on 1, 3 and 5 November 2022, 16 and 28 January 2023 was cancelled due to adverse weather. No substitution would be arranged for such cancellation since it is impossible to maintain the monitoring frequency as three times a week for the event of marine water quality monitoring cancellation in between time with respect to the fact that not less than 36 hours interval shall be followed for two monitoring days as required by the EM&A Manual Clause 5.1.6 (b) for the project.

   viii.        In accordance with the action level and limit level in Baseline Monitoring Report Rev. 9.2 agreed by EPD on 2 September 2022, 7 action level and 0 limit level exceedances on Suspended Solids (SS) were recorded in the reporting period. It can be concluded that all the SS exceedances were possibly due to natural runoff from streams to the sea in the reporting period.

     ix.        Action Level exceedances were recorded on 19 November 2022 on SS at SR15 during flood tide. In view that the water quality at monitoring stations located nearest the marine work site (SR4, SR5 and SR6) were well below Action Level and the silt curtain was in proper condition, the exceedances were possible in relation to the changes of water quality in the vicinity of the water quality monitoring station and not project related.

      x.        Action Level exceedances was recorded on 2, 14, 19 and 26 December 2022 on SS during ebb and flood tide. SR4 located at upstream of construction site during mid-flood such that the Action Level exceedances on SS on 19 December 2022 in general was contributed by upstream sources before entering the submarine outfall construction site. Similarly, SR9 located at upstream of construction site during mid-ebb such that the Action Level exceedances on SS on 2 December 2022 in general was contributed by upstream sources before entering the submarine outfall construction site. Co-related the monitoring dates with those days with recorded marine works activities, pilot hole drilling within the fully enclosed silt curtain on 2 December 2022, set up generator on working barge not in contact with water on 19 December 2022, no activity on 14 and 26 December 2022, the silt curtain was in proper condition and no marine dredging works were active in the reporting month. Mitigation measures including remove debris and loose material on working barge with working area was fully enclosed by silt curtain with good condition. It can be concluded that all the SS exceedances in the reporting period were possible in relation to the changes of water quality in the vicinity of the water quality monitoring station and not project related.

 

Ecological Impact Monitoring

     xi.        Transplanting works for plant species, Aquilaris sinensis, was completed on 26 April 2022. Maintenance works for trees in holding nursery have commenced.

    xii.        As per latest version of PTP, four tree found (1 no. of Aquilaria sinensis and 3 nos. of Gmelina chinensis) within the site of SSWSTW which are considered to be the plant species with conservative importance for temporarily transplanted to the nursery at Kam Tin and eventually be transplanted to Pui O Pumping Station.

   xiii.        The weekly site audit was carried out by ET include checking whether good site practices are being properly implemented by the Contractor.

   xiv.        The extent of the work site boundaries was checked by the ET during the weekly site audit.

Complaint log

    xv.        One environmental complaint regarding the water quality at Pui O Beach was recorded in the reporting period. Upon investigation, the works activities at Pui O Pumping Station (POPS) including land-based and marine based did not result in any unacceptable environmental impacts to the surrounding environment as reviewed with the relevant works activities and  environmental requirements for the Project, and it was considered as non-project related.

 

Notifications of Any Summons and Successful Prosecutions

   xvi.        No environmental notification of any summons and successful prosecution regarding the construction works was recorded in present quarter.

 

1      Introduction

1.1          Scope of the Report

1.1.1.     Lam Environmental Services Limited (LES) has been appointed to work as the Environmental Team (ET) under Environmental Permit (EP) no. EP-538/2017 to implement the Environmental Monitoring and Audit (EM&A) programme as stipulated in the EM&A Manual of the approved Environmental Impact Assessment (EIA) Report for Outlying Islands Sewerage Stage 2 - South Lantau Sewerage Works (Register No.: AEIAR-210/2017).

1.1.2.     The Quarterly EM&A Summary Report was prepared according to Section 12.3 of the Project EM&A Manual.

1.2          Structure of the Report

Section 1        Introduction – details the scope and structure of the report

 

Section 2        Basic Project Information – a synopsis of project organization, programme contacts of key management, and a synopsis of work undertaken in the reporting period.

           

Section 3        A Brief Summary of EM&A requirements – including monitoring parameters, environmental quality performance limits (Action and Limit levels); and environmental mitigation measure, as recommended in the EIA Report.

                      

Section 4        Implementation Status – Advice on the implementation status of environmental protection and pollution control/mitigation measures, as recommended in the EIA Report and summarised in the updated implementation schedule.

 

Section 5        Monitoring Results Analysis – the trends of the monitoring parameters in present quarter; advice on the solid and liquid waste management status.

                      

Section 6        Summary of Non-Compliance (exceedances) of the environmental quality performance limits, Complaints, Notification of Summons and Successful Prosecutions

A brief review of the reasons for and the implications of non-compliance and a summary description of the actions taken and any follow-up procedures related to earlier non-compliance.

A summary record of all complaints received (written or verbal) for each media, liaison and consultation undertaken, actions and follow-up procedures taken;

A summary record of notifications of summons and successful prosecutions for breaches of the current environmental protection/pollution control legislations, including locations and nature of the breaches, investigation, follow-up actions taken and results.

                      

Section 7        Comments and Recommendations – such as effectiveness and efficiency of the mitigation measures, improvement in the EM&A programme, if any.

 

Section 8        Conclusion and Project Proponent’s contacts and hotline telephone number for the public to make enquiries

2.         Basic Project Information

2.1          Project Organization and Key Contact Personnel

2.1.1       Drainage Services Department is the overall project controllers for the Project. For the construction phase of the Project, Contractor(s), Environmental Team and Independent Environmental Checker are appointed to manage and control environmental issues.  Key personnel and contact particulars are summarised in Figure 2.1 and Table 2.1:

Table 2.1 Contact Details of Key Personnel

Party	Role	Post	Name	Contact No.	Contact Fax
Drainage Services Department (DSD)	The Engineer for the Contract	Engineer	Mr. Silas Chan	2594 7272	3104 6426
Binnies Hong Kong Limited	Engineer’s Representative	Resident Engineer	Mr. Clayton Lei	3529 3013	-
Kwan Lee – Chun Wo Joint Venture	Contractor	Site Agent	Mr. Charles Tse	9270 3384	2744 6937
		Environmental Officer	Ms. Shirley Kong	5162 5933
SMEC Hong Kong	Independent Environmental Checker (IEC)	Independent Environmental Checker (IEC)	Ms. Kitty Lee	3995 8140	3995 8101
Lam Environmental Services Limited	Environmental Team (ET)	Environmental Team Leader (ETL)	Mr. Derek Lo	2882 3939	2882 3331

 

2.2          Construction Programme

2.2.1       The proposed sewerage works will collect the sewage generated from the unsewered areas of Shui Hau, Tong Fuk, Cheung Sha, San Shek Wan, Pui O and Ham Tin in South Lantau (i.e. within the Project Catchment Area) and convey it to a proposed sewage treatment works at San Shek Wan for treatment and disposal into outer bay of Pui O/ Chi Ma Wan via a submarine outfall.

2.2.2       The entire Project are divided into three contracts. Contract No. DC/2020/20 (the Contract) would have the following implementations as demonstrated in Figure 2.2.

2.2.3       The major components of the Project under Environmental Permit (EP) (EP No. EP-538/2017) comprises: (i) construction of sewage treatment works at San Shek Wan (SSWSTW) and associated submarine outfall; (ii) construction of sewage pumping station at Pui O (POSPS); (iii) village sewage works at Pui O; and (iv) trunk sewers and rising mains on carriageways.

 

3.      A Brief Summary of EM&A Requirements

3.1  Monitoring Parameters

Noise Monitoring

3.1.1       The construction noise level shall be measured in terms of the A-weighted equivalent continuous sound pressure level (L_eq). L_eq (30min) should be used as the monitoring parameter. Supplementary information for data auditing, statistical results such as L₁₀ and L₉₀ shall also be obtained for reference.

3.1.2       For impact monitoring for construction of village sewers / rising main, noise monitoring should be undertaken on weekly basis.  One set of L_eq (30min) noise level as six consecutive L_eq (5min) between 07:00-19:00 hours on normal weekdays.

Water Quality Monitoring

3.1.3       In construction phase, the levels of dissolved oxygen (DO), temperature, turbidity and salinity should be measured in-situ while suspended solids (SS) is determined by laboratory analysis.

Ecological Impact Monitoring

3.1.4       Monitoring in the form of regular site inspections should be carried out to ensure ecological measures in the form of tree transplantation and establishment are being implemented and effective for plant species of conservation importance (e.g. Aquilaria sinensis).

3.2  Environmental Quality Performance Limits

Noise Monitoring

3.2.1       No action and limit level exceedances were recorded in construction noise level in the reporting period.

Water Quality Monitoring

3.2.2       Marine-based construction works had been commenced since 19 April 2022, marine water quality monitoring was initialised since 12 April 2022. 

3.2.3       Water quality monitoring on 1, 3 and 5 November 2022, 16 and 28 January 2023 was cancelled due to adverse weather. No substitution would be arranged for such cancellation since it is impossible to maintain the monitoring frequency as three times a week for the event of marine water quality monitoring cancellation in between time with respect to the fact that not less than 36 hours interval shall be followed for two monitoring days as required by the EM&A Manual Clause 5.1.6 (b) for the project.

3.2.4       In accordance with the action level and limit level in Baseline Monitoring Report Rev. 9.2 agreed by EPD on 2 September 2022, 7 action level and 0 limit level exceedances on SS were recorded in the reporting period. It can be concluded that all the SS exceedances were possibly due to natural runoff from streams to the sea in the reporting period.

3.2.5       Action Level exceedances were recorded on 19 November 2022 on SS at SR15 during flood tide. Checked with the Contractor and Resident Site Staff (RSS) on the marine works activities, pilot hole drilling within the fully enclosed silt curtain on 17 November 2022, no activity on 19 November 2022, no marine dredging works were active in the reporting month. In view that the water quality at monitoring stations located nearest the marine work site (SR4, SR5 and SR6) were well below Action Level and the silt curtain was in proper condition, the exceedances were possible in relation to the changes of water quality in the vicinity of the water quality monitoring station and not project related.

3.2.6       Action Level exceedances was recorded on 2, 14, 19 and 26 December 2022 on SS during ebb and flood tide. SR4 located at upstream of construction site during mid-flood such that the Action Level exceedances on SS on 19 December 2022 in general was contributed by upstream sources before entering the submarine outfall construction site. Similarly, SR9 located at upstream of construction site during mid-ebb such that the Action Level exceedances on SS on 2 December 2022 in general was contributed by upstream sources before entering the submarine outfall construction site. Co-related the monitoring dates with those days with recorded marine works activities, pilot hole drilling within the fully enclosed silt curtain on 2 December 2022, set up generator on working barge not in contact with water on 19 December 2022, no activity on 14 and 26 December 2022, the silt curtain was in proper condition and no marine dredging works were active in the reporting month. Mitigation measures including remove debris and loose material on working barge with working area was fully enclosed by silt curtain with good condition. It can be concluded that all the SS exceedances in the reporting period were possible in relation to the changes of water quality in the vicinity of the water quality monitoring station and not project related.

3.2.7       Water quality monitoring is evaluated against Action and Limit Levels. The derived Action and Limit Level proposed in Baseline Monitoring Report Rev. 9.2 was agreed by EPD on 2 September 2022. Action and Limit Levels of marine water quality monitoring have been set with reference to the derived criteria as shown in Table 3.1 below.

Table 3.1     Action and Limit Levels of Water Quality

 

Notes (with proposed amendments in AL/LL in underlined text):

A. “Depth-averaged” is calculated by taking the arithmetic means of reading of all three depths.

B.  For DO, non-compliance of the water quality limits occurs when monitoring result is lower than the limits.

C.  For SS and turbidity, non-compliance of the water quality limits occurs when monitoring result is higher than the limits.

D. Action Level and Limit Level with 95%-ile / 99%-ile derived from baseline data “and” 20% / 30% exceedance of control station proposed in Baseline Monitoring Report.

 

Ecological monitoring

3.2.8       Transplanting works for plant species, Aquilaris sinensis, was completed on 26 April 2022. Maintenance works for trees in holding nursery have commenced.

3.2.9       Monitoring of maintenance works for the transplanted plant species was conducted at the holding nursery while in the reporting period.

3.2.10    As per latest version of PTP, four tree found (1 no. of Aquilaria sinensis and 3 nos. of Gmelina chinensis) within the site of SSWSTW which are considered to be the plant species with conservative importance for temporarily transplanted to the nursery at Kam Tin and eventually be transplanted to Pui O Pumping Station.

4.      Implementation Status

4.1  Advice on the implementation status of environmental protection and pollution control/mitigation measures

4.1.1       Mitigation measures according to the environmental mitigation implementation schedule in Annex A of EM&A Manual were generally implemented by the Contractor.  Hence, the EM&A programme was considered effective and shall be maintained.               

4.2  Environmental Mitigation Measures

4.2.1       Environmental mitigation measures mentioned the EIA Report were weekly reviewed and recorded in Weekly Environmental Site Audit Checklist.  Also, a summary of the submission status of the reporting quarter on submissions and measures mentioned in Environmental Permit (EP-538/2017) are shown in Table 4.1.

Table 4.1 Summary of submission status under EP-538/2017

 

4.3  Environmental monitoring requirements and contractual requirements

4.3.1       A summary of the submission status for the reporting period on licences and/or permits on environmental protection pertinent to the Project is shown in Table 4.2.

Table 4.2 Summary of the current status on licences and/or permits on environmental protection pertinent to the Project

Permits and/or Licences	Permit. No. / Account No.	Issued Date	Valid Period & Expiry Date	Status
Notification of Works Under APCO	466408	14 Apr 2021	N/A	Valid
Wastewater Discharge Licence under Water Pollution Control Ordinance	SSWSTW: WT00039636-2021	30 Dec 2021	30-12-2021 to 31-12-2026	Valid
	POPS: WT00039820-2021	31 Dec 2021	31-12-2021 to 31-12-2026	Valid
	SSWSTW: Gravity Sewer & Raising Main: WT00042613-2022	09 Jan 2023	09-01-2023 to 31-01-2028	Valid
Billing account under Waste Disposal Ordinance	Account No.: 7040411	05 May 2021	N/A	Valid
Registration as a Chemical Waste Producer	0000-931-K3428-01	13 May 2021	N/A	Valid
Construction Noise Permit under Noise Control Ordinance for SSWSTW	GW-RS0642-22	3 Aug 2022	05-08-2022 to 02-02-2023	Valid
Construction Noise Permit under Noise Control Ordinance for POSPS	GW-RS0840-22	3 Oct 2022	05-10-2022 to 26-03-2023	Valid

  Note: Only include those valid or under application; fill in “N/A” for non-applicable item(s).

 

 

3.1. 

5.      Monitoring Results Analysis

5.1    Noise Monitoring

5.1.1       Noise monitoring was conducted at eight (8) noise monitoring stations (N12a, N12b, N13, N14, N15b, N16a, N16b and N17) once per week in the reporting period.

5.1.2       School examination was taken place at N17 – Bui O Public School from 14 to 16 November 2022 in the reporting month, the limit level shall be adjusted to 65dB(A) during this period.

5.1.3       Noise monitoring location plans with sensitive receivers are shown in Figure 5.1.

5.1.4       Noise monitoring results measured in the reporting period were reviewed and summarised.  Noise monitoring graphical presentation can be referred to Appendix 5.1.

5.1.5       No action and limit level exceedances were recorded in construction noise level in the reporting period.

5.2    Marine Water Quality Monitoring

5.2.1       Marine Water quality monitoring involves nine (9) monitoring stations (seven impact & two control stations) three days per week in the reporting period starting from 12 April 2022.

5.2.2       Marine Water monitoring location plans with sensitive receivers are shown in Figure 5.2ui.

5.2.3       Water quality monitoring is evaluated against Action and Limit Levels. The derived Action and Limit Level proposed in Baseline Monitoring Report Rev. 9.2 was agreed by EPD on 2 September 2022.

5.2.4       Water quality monitoring on 1, 3 and 5 November 2022, 16 and 28 January 2023 was cancelled due to adverse weather. No substitution would be arranged for such cancellation since it is impossible to maintain the monitoring frequency as three times a week for the event of marine water quality monitoring cancellation in between time with respect to the fact that not less than 36 hours interval shall be followed for two monitoring days as required by the EM&A Manual Clause 5.1.6 (b) for the project.

5.2.5       In accordance with the action level and limit level in Baseline Monitoring Report Rev. 9.2 agreed by EPD on 2 September 2022, 7 action level and 0 limit level exceedances on SS were recorded in the reporting period. It can be concluded that all the SS exceedances were possibly due to natural runoff from streams to the sea in the reporting period.

5.2.6       Action Level exceedances were recorded on 19 November 2022 on SS at SR15 during flood tide. In view that the water quality at monitoring stations located nearest the marine work site (SR4, SR5 and SR6) were well below Action Level and the silt curtain was in proper condition, the exceedances were possible in relation to the changes of water quality in the vicinity of the water quality monitoring station and not project related.

5.2.7       Action Level exceedances was recorded on 2, 14, 19 and 26 December 2022 on SS during ebb and flood tide. SR4 located at upstream of construction site during mid-flood such that the Action Level exceedances on SS on 19 December 2022 in general was contributed by upstream sources before entering the submarine outfall construction site. Similarly, SR9 located at upstream of construction site during mid-ebb such that the Action Level exceedances on SS on 2 December 2022 in general was contributed by upstream sources before entering the submarine outfall construction site. Co-related the monitoring dates with those days with recorded marine works activities, pilot hole drilling within the fully enclosed silt curtain on 2 December 2022, set up generator on working barge not in contact with water on 19 December 2022, no activity on 14 and 26 December 2022, the silt curtain was in proper condition and no marine dredging works were active in the reporting month. Mitigation measures including remove debris and loose material on working barge with working area was fully enclosed by silt curtain with good condition. It can be concluded that all the SS exceedances in the reporting period were possible in relation to the changes of water quality in the vicinity of the water quality monitoring station and not project related.

5.2.8       Marine water quality monitoring results measured in this reporting period are reviewed and summarized. Details of marine water quality monitoring graphical presentation and the summary of exceedance of action and /limit levels of WQM can be referred to Appendix 5.2.

5 

 

5.3    Ecological Impact Monitoring

5.3.1       Transplanting of the trees of Aquilaris sinensis was completed on 26 April 2022. Maintenance works for trees in holding nursery have commenced.

5.3.2       Monitoring of maintenance works for the transplanted plant species was conducted at the holding nursery while in the reporting period.

5.3.3       As per latest version of PTP, four tree found (1 no. of Aquilaria sinensis and 3 nos. of Gmelina chinensis) within the site of SSWSTW which are considered to be the plant species with conservative importance for temporarily transplanted to the nursery at Kam Tin and eventually be transplanted to Pui O Pumping Station.

6 

 

5.4       Waste Management

5.4.1       The quantities of waste for disposal in present quarter are summarized in Table 5.1. The Quarterly Summary Waste Flow Table is shown in Appendix 5.3.

 

Table 5.1 Summary of Quantities of Waste Material (November, December 2022 and January 2023)

Waste Type	Quantity for reporting quarter	Cumulative Quantity-to-Date
Hard Rock and Large Broken Concrete (Inert) (in ‘000m3)	0	0
Reused in this Contract (Inert) (in ‘000m3)	0	0
Reused in other Projects (Inert) (in ‘000m3)	0	0
Disposal as Public Fill (Inert) (in ‘000m3)	0.63633	9.19043
Metals (in ‘000kg)	5.92770	7.49760
Paper / Cardboard Packing (in ‘000kg)	0.06060	0.28998
Plastics (in ‘000kg)	0.00640	0.02976
Chemical Wastes (in ‘000kg)	0	0
General Refuses (in ‘000kg)	40.9000	430.03000
*: Further breakdown into sub-group if considered applicable;

 

6.      Complaints, Notification of Summons and Prosecution

6.        

6.0.        

6.1.1       One environmental complaint regarding the water quality at Pui O Beach was recorded in the reporting period. Upon investigation, the works activities at Pui O Pumping Station (POPS) including land-based and marine based did not result in any unacceptable environmental impacts to the surrounding environment as reviewed with the relevant works activities and  environmental requirements for the Project, and it was considered as non-project related.

Table 6.1      Summary of Complaints

6.1.2       No notification of summons and successful prosecution regarding construction works were recorded in the reporting period.

6.1.3       Cumulative statistic on complaints and successful prosecutions are summarized in Table 6.2 and Table 6.3 respectively.

Table 6.2 Cumulative Statistics on Complaints

Reporting Period	No. of Complaints
November, December 2022 - January 2023	1
Project commencement to the end of last reporting quarter	2
Total	2

 

Table 6.3 Cumulative Statistics on Successful Prosecutions

Environmental Parameters	Cumulative No. Brought Forward	No. of Successful Prosecutions this month (Offence Date)	Cumulative No. Project-to-Date
Air	-	0	0
Noise	-	0	0
Water	-	0	0
Waste	-	0	0
Other	-	0	0
Total	-	0	0

 

7.      Comments and Recommendations

7.        

7.0.        

7.1.1       In the reporting period, the principal work activities conducted are as follow.

Table 7.1 Construction Activities in Past 3 Months

 

7.1.2       The recommended mitigation measures for the past 3 months are listed below:

·         Provide caring measures for the health, form and structural conditions for transplant trees including Aquilaris sinensis in holding nursery;

·         Fully implement tree preservation works on site and holding nursery to ensure compliance of relevant legislation and guidelines stated in EM&A Manual.

·         Implementation of noise pollution control in accordance with Construction Noise Mitigation Plan;

·         Dust control during dust generating works;

·         Adopt surface drainage and sediment control facilities for sewage installation in village and public roads;

·         Adopt temporary drainage and sediment control facilities on Site;

·         Vehicle wheel-washing and body washing facilities should be provided at the site entrance;

·         Regular water spraying on drilling and excavation works for dust control; and

·         Proper waste handling, recycling and storage.

·         To inspect the condition of silt curtains on regular basis, and after adverse weather including any rainstorms and typhoons in wet season.

The implemented mitigation measures are considered effective.

 

 

 

8.      Conclusion

8.1  Noise Monitoring.

8.1.1       Noise monitoring was conducted at eight (8) noise monitoring stations (N12a, N12b, N13, N14, N15b, N16a, N16b and N17) once per week in the reporting period.

8.1.2       No action or limit level exceedance was recorded in construction noise level in this present quarter.

 

8.2  Water Quality Monitoring

8.2.1       Marine-based construction works commenced on 19 April 2022, water quality monitoring was commenced on 12 April 2022.

8.2.2       Water quality monitoring on 1, 3 and 5 November 2022, 16 and 28 January 2023 was cancelled due to adverse weather.

8.2.3       In accordance with the action level and limit level in Baseline Monitoring Report Rev. 9.2 agreed by EPD on 2 September 2022, 7 action level and 0 limit level exceedances on SS were recorded in the reporting period. It can be concluded that all the SS exceedances were possibly due to natural runoff from streams to the sea in the reporting period.

8.2.4       Action Level exceedances were recorded on 19 November 2022 on SS at SR15 during flood tide. In view that the water quality at monitoring stations located nearest the marine work site (SR4, SR5 and SR6) were well below Action Level and the silt curtain was in proper condition, the exceedances were possible in relation to the changes of water quality in the vicinity of the water quality monitoring station and not project related.

8.2.5       Action Level exceedances was recorded on 2, 14, 19 and 26 December 2022 on SS during ebb and flood tide. SR4 located at upstream of construction site during mid-flood such that the Action Level exceedances on SS on 19 December 2022 in general was contributed by upstream sources before entering the submarine outfall construction site. Similarly, SR9 located at upstream of construction site during mid-ebb such that the Action Level exceedances on SS on 2 December 2022 in general was contributed by upstream sources before entering the submarine outfall construction site. Co-related the monitoring dates with those days with recorded marine works activities, pilot hole drilling within the fully enclosed silt curtain on 2 December 2022, set up generator on working barge not in contact with water on 19 December 2022, no activity on 14 and 26 December 2022, the silt curtain was in proper condition and no marine dredging works were active in the reporting month. Mitigation measures including remove debris and loose material on working barge with working area was fully enclosed by silt curtain with good condition. It can be concluded that all the SS exceedances in the reporting period were possible in relation to the changes of water quality in the vicinity of the water quality monitoring station and not project related.

 

8.3  Ecological Impact Monitoring

8.3.1       Transplanting works for plant species, Aquilaris sinensis, was completed on 26 April 2022. Maintenance works for trees in holding nursery have commenced.

8.3.2       Monitoring of maintenance works for the transplanted plant species was conducted at the holding nursery while in the reporting period.

8.3.3       As per latest version of PTP, four tree found (1 no. of Aquilaria sinensis and 3 nos. of Gmelina chinensis) within the site of SSWSTW which are considered to be the plant species with conservative importance for temporarily transplanted to the nursery at Kam Tin and eventually be transplanted to Pui O Pumping Station.

 

8.4  Review of the Reasons for and the Implications of Non-compliance

8.4.1       No environmental non-compliance was recorded in present quarter.

 

8.5  Summary of action taken in the event of and follow-up on non-compliance

8.5.1       There was no particular action taken since no non-compliance was recorded in present quarter.