Job No.: TCS00975/18

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CEDD Contract Agreement No. EDO/04/2018 -

Environmental Team for Cross Bay Link, Tseung Kwan O

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Baseline Monitoring Report

 

 

 

 

 

 

 

 

 

 

 

 

Prepared For

Civil Engineering and Development Department

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Quality Index

Date

Reference No.

Prepared By

Approved By

11 February 2019

TCS00975/18/600/R0027v3

 

 

Martin Li

Environmental Consultant

TW Tam

Environmental Team

Leader

 

Version

Date

Description

1

16 November 2018

First Submission

2

9 January 2019

1st Revision

3

11 February 2019

2nd Revision

 

 

 


 

 

 

 

 

 

executive summary

ES.01     Action-United Environmental Services & Consulting (AUES) was awarded the Civil Engineering and Development Department (CEDD) Contract Agreement No. EDO/04/2018 - Environmental Team for Cross Bay Link, Tseung Kwan O (hereinafter called “the Contract Agreement).

ES.02     According to the Approved Environmental Monitoring & Audit (EM&A) Manual, air quality, noise and water quality monitoring are required to be conducted during the construction phase of Cross Bay Link, Tseung Kwan O (hereinafter called “the Project”). As part of the EM&A programme, baseline monitoring is required to determine the ambient environmental conditions.  Prior to the commencement of construction work of the Project, baseline water quality monitoring at the all designated stations was carried out from 21st September 2018 to 22nd October 2018. In addition, the air quality at the interim alternative locations was carried out from 30th October 2018 to 12th November 2018 while noise baseline monitoring was carried out from 29th October 2018 to 13th November 2018. 

ES.03     This report summarizes the key findings and presents the process and rationale behind determining a set of Action and Limit Levels (A/L Levels) of air quality, construction noise and water quality based on the baseline data obtained.  These A/L Levels will serve as the yardsticks for assessing the acceptability of the environmental impact during construction phase of the Project Works.  They are statistical in nature and derived according to the criteria set out in Approved EM&A Manual.

ES.04     Results of the derived Action and Limit Levels for air quality, construction noise and water quality are given in Tables ES-1, ES-2 and ES-3 as follows.

Table ES-1           Action and Limit Levels of Air Quality Monitoring

Monitoring Station

Action Level (mg /m3)

Limit Level (mg/m3)

1-hour TSP

24-hour TSP

1-hour TSP

24-hour TSP

Interim Alternative Location – Lohas Park Phase 2A (AM4)

278

NA

500

NA

Interim Alternative Location – the Project site office (AM5)

NA

190

NA

260

Remarks: Air quality monitoring will be resumed at the designated locations AM1, AM2 and AM3 once they are available and permission are granted.

Table ES-2           Action and Limit Levels of Construction Noise Monitoring

Monitoring Location

Action Level

Limit Level in dB(A) (Leq30min)

Time Period: 0700-1900 hours on normal weekdays

Interim Alternative Location – Lohas Park Phase 2A (CNMS-5)

When one or more documented complaints to be received

75

Remarks:

(i)          Construction noise monitoring will be resumed at the designated locations CNMS-1, CNMS-2, CNMS-3 and CNMS4 once they are available and permission are granted;

(ii)        The designated locations CNMS-1, CNMS-2 and CNMS-3 are located at residential building which are still under construction, Limit Level of 75dB(A) will be adopted until they are occupied;

(iii)      The designated location CNMS-4 is located at planned school and still not yet to construction.  When the school occupied and operated, Limit Level of 70dB(A) should be adopted and should be reduced to 65dB(A) during examination period; and

(iv)       If construction works are required during restricted hours, the conditions stipulated in the construction noise permit issued by the Noise Control Authority shall be followed.

Table ES-3           Action and Limit Levels of Water Quality Monitoring

Monitoring Station

Depth Average of SS (mg/L)

Action Level

Limit Level

CC1

7.8

OR 120% of upstream control station at the same tide of the same day

(Control Station C3 at Ebb tide and Control Station C4 at Flood tide), whichever is higher

9.3

OR 130% of upstream control station at the same tide of the same day

(Control Station C3 at Ebb tide and Control Station C4 at Flood tide), whichever is higher

CC2

9.0

9.2

CC3

8.2

9.0

CC4

13.8

15.4

CC13

8.9

10.3

SWI1

8 mg/L

10 mg/L

 



Monitoring Location

Dissolved Oxygen (mg/L)

Depth Average of Surface and Mid-depth

Bottom

Action Level

Limit Level

Action Level

Limit Level

CC1

5.8

5.7

5.3

5.2

CC2

5.8

5.7

5.3

5.1

CC3

5.5

5.4

4.9

4.7

CC4

5.7

5.7

5.5

5.4

CC13

5.6

5.5

5.3

5.2

SWI1

5.4

4.8

5.1

5.0

 

Monitoring Location

Depth Average of Turbidity (NTU)

Action Level

Limit Level

CC1

5.8

OR 120% of upstream control station at the same tide of the same day

(Control Station C3 at Ebb tide and Control Station C4 at Flood tide), whichever is higher

6.0

OR 130% of upstream control station at the same tide of the same day

(Control Station C3 at Ebb tide and Control Station C4 at Flood tide), whichever is higher

CC2

4.6

5.5

CC3

4.8

5.4

CC4

6.1

7.1

CC13

6.0

6.3

SWI1

6.1

7.1

Notes:

(a)       For DO, non-compliance of water quality limits occurs when monitoring result is lower than the limits

(b)       For SS and turbidity, in order to better utilize the baseline data in the derivation of water quality limit, the water quality limits were set as 95/99%-ile of baseline data OR 120/130% of upstream control station at the same tide of the same day, whichever is higher.

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

(d)       For SS at SWI1, the Action and Limit Level were set according the approved EM&A Manual based on the assessment criteria of the WSD salt water intake.

ES.05     In cases where exceedance of these criteria occurs, actions should be carried out in accordance with the Event Action Plan as showed in the Approved EM&A Manual.


Table of Contents

 

1.0         Introduction                                                                                                            1

Background                                                                                                              1

Report Structure                                                                                                    1

2.0         Summary of Baseline Monitoring Requirement                              3

General                                                                                                                        3

Monitoring Parameters                                                                                     3

Monitoring Locations                                                                                         3

Monitoring Frequency and Period                                                              4

Monitoring Equipment                                                                                        5

Derivation of Action/Limit (A/L) Levels                                                      6

Event Action Plan                                                                                                  7

3.0         Baseline monitoring methodology                                                         8

General                                                                                                                        8

Location of Baseline Monitoring                                                                8

Monitoring Equipment of Baseline Monitoring                                  8

Monitoring Procedure                                                                                       9

Meteorological Information                                                                         12

Equipment Calibration                                                                                       12

Data Management and Data QA/QC Control                                            12

4.0         Baseline Monitoring Results                                    13

General                                                                                                                        13

Results of Air Quality Monitoring                                                             13

Results of Background Noise Monitoring                                             13

Results of Marine Water Quality Monitoring                                      14

Discussion and Recommendations                                                               15

5.0         Conclusions and Recommentations                             17

Conclusions                                                                                                              17

Recommendations                                                                                                  18

 

List of TABLES

Table 2-1   Summary of Baseline Monitoring Parameters

Table 2-2   Designated Air Quality Monitoring Location recommended in EM&A Manual

Table 2-3   Designated Construction Noise Monitoring Location Recommended in

Table 2-4   Proposed Alternative Monitoring Location

Table 2-5   Location of Water Quality Monitoring Station

Table 2-6  Derivation of Action and Limit Levels for Air Quality

Table 2-7   Derivation of Action and Limit Levels for Construction Noise

Table 2-8   Derivation of Action and Limit Levels for Water Quality

Table 3-1   Air Quality Monitoring Equipment

Table 3-2   Construction Noise Monitoring Equipment

Table 3-3   Water Monitoring Equipment

Table 3-4   Testing Method and Reporting Limit of the Chemical Analysis

Table 4-1   Summary of 1-hour TSP and 24-Hr Monitoring Results – Alternative Monitoring Location AM4 (1-Hour TSP) and AM5 (24-Hour TSP)

Table 4-2   Action and Limit Levels for Air Quality Monitoring

Table 4-3   Summary of Noise Monitoring Results – Alternative Monitoring Location CNMS-5

Table 4-4   Action / Limit Levels of Construction Noise Monitoring

Table 4-5   Water Depths of Water Quality Monitoring Stations Summary

Table 4-6   Summaries of Maine Water In-situ Measurement Results

Table 4-7   Summaries of Suspended Solids Analysis Results

 

List of Appendices

Appendix A  Project site layout plan

Appendix B  Designated Monitoring locations and Alternative Air Noise Monitoring Location

Appendix C  calibration certificates of Equipment and the Accreditation Laboratory Certificate

Appendix D Baseline monitoring schedule

Appendix E  Database for 24-hour TSP Data of Air Quality

Appendix F  Database for Noise Measurement Data

Appendix G Database for Marine Water Quality Monitoring Data with Laboratory Result

Appendix H Meteorological Data during baseline monitoring period

Appendix I   Event Action Plan (Air Quality and Construction Noise)

Appendix J   Tidal Pattern of Junk Bay from Hong Kong Tidal Stream Prediction System

 

 

 


1.0              Introduction

Background

1.01          Cross Bay Link, Tseung Kwan O is a designated project under Part I of Schedule 2 to the EIAO (Cap. 499) and Environmental Permit No. EP-459/2013 is granted from EPD for construction and operation phases of the Project. The Project commenced on 10 August 2018.

 

1.02          AUES was awarded the CEDD Contract Agreement No. EDO/04/2018 - Environmental Team for Cross Bay Link, Tseung Kwan O (hereinafter called “the Service Contract”). The Services under the Service Contract is to provide environmental monitoring and audit (EM&A) services for the Works Contracts pursuant to the requirement of Environmental Team (ET) under the Approved EM&A Manual to ensure that the environmental performance of the Works Contracts comply with the requirement specified in the EM&A Manual and EIA Report of Agreement No. CE 43/2008 (HY) Cross Bay Link, Tseung Kwan O - Investigation and other relevant statutory requirements.

 

1.03          The Project involved two major infrastructure works contracts.  The scope of works covered in these works contracts namely Contract 1 and 2 comprises as listed below.  In addition, route-wide traffic control and surveillance system (TCSS) will be implemented along Cross Bay Link (CBL) of the Project.

Contract 1 (Contract No. NE/2017/07) – Cross Bay Link, Tseung Kwan O - Main Bridge and Associated Works

(i)            400m section of marine viaducts of steel deck sections including the Eternal Arch Bridge;

(ii)          600m section of marine viaducts of concrete deck sections; and

(iii)        An E&M Plantroom and associated building services and E&M provisions

Contract 2 (Contract No. NE/2017/08) – Cross Bay Link, Tseung Kwan O - Road D9 and Associated Works

(i)            Elevated deck structures along Road D9;

(ii)          A 210m section of cycle track and footpath ramp bridge;

(iii)        A 630m section of noise semi-enclosure covering the entire length of Road D9, and;

(iv)        Lift, staircase, modification of existing seawall along Road D9, landscaping and miscellaneous works.

Contract 3 (Contract No. NE/2017/06) - Lam Tin Tunnel - Traffic Control and Surveillance System (TCSS) and Associated Works (for portions of Cross Bay Link)

(i)            Traffic control and surveillance system (TCSS) works

 

1.04          Action-United Environmental Services & Consulting (hereinafter referred as “AUES”) has been commissioned as an Environmental Team (hereinafter referred as “the ET”) to implement the relevant EM&A programme in accordance with the approved EM&A Manual, as well as the associated duties.

 

1.05          As part of the EM&A programme, baseline monitoring is required to determine the ambient environmental conditions.  Baseline monitoring including air quality, background noise and water quality were conducted in periods from 21st September 2018 to 13th November 2018 before construction work of Project commencement.

 

1.06          This Baseline Monitoring Report presents the details of the baseline study including project background, monitoring methodology, monitoring results, summary of findings, and Action/Limit (A/L) Levels established for subsequent use in the Project construction phase EM&A programme.

 

Report Structure

1.07          This Baseline Monitoring Report summarizes the key findings and presents the process and rationale behind determining a set of Action and Limit Levels (A/L Levels) of air quality, construction noise and water quality based on the baseline monitoring data.  These A/L Levels will serve as the yardsticks for assessing the acceptability of the environmental impact during construction phase of the Project Works.  The Baseline Monitoring Report is structured into the following sections:-

Section 1        Introduction

Section 2        Summaries of Baseline Monitoring Requirement.

Section 3        Baseline Monitoring Methodology

Section 4        Baseline Monitoring Results

Section 5        Conclusion and Recommendation

 


2.0              Summary of Baseline Monitoring Requirement

General

2.01          The Environmental Monitoring and Audit requirements are set out in the Approved EM&A manual.  Environmental issues such as air quality, construction noise and water quality were identified as the key issues during the construction phase of the Project.

 

2.02          This report presents the results obtained during the baseline monitoring of air quality, background noise and water quality in periods from 21st September 2018 to 13th November 2018.  A summary of the baseline EM&A requirements for air quality, background noise and water quality monitoring are presented in the sub-sections below.

 

Monitoring Parameters

2.03          The baseline monitoring programme covers the following environmental aspects:

      Air Quality;

      Construction Noise; and

      Water Quality

 

2.04          A summary of baseline monitoring parameters is presented in Table 2-1:

Table 2-1           Summary of Baseline Monitoring Parameters

Environmental Issue

Parameters

Air Quality

Ÿ  1-hour TSP by Real-Time Portable Dust Meter; and

Ÿ  24-hour TSP by High Volume Air Sampler.

Background Noise

Ÿ  LAeq(30min) for daytime (0700 – 1900) of normal working day;

Ÿ  LAeq(15min) for evening (1900 – 2300), night-time (2300 – 0700 next day) and public holidays (include Sundays) between 0700 and 2300 on all  days

Water Quality

Ÿ  In-situ measurement – Dissolved Oxygen (DO) concentration (mg/L) & saturation (%), pH, Salinity (mg/L), Temperature (ºC) and Turbidity (NTU); and

Ÿ  Laboratory analysis – SS (mg/L)

 

Monitoring Locations

Air Quality and Construction Noise

2.05          According to the Approved EM&A Manual Section 5.4 and Section 6.3, three (3) representative air sensitive receivers (ASR) and four (4) representative noise sensitive receivers were designated as monitoring stations.  The designated air quality and noise monitoring locations are listed in Table 2-2 and Table 2-3, and shown in Appendix B.

Table 2-2           Designated Air Quality Monitoring Location recommended in EM&A Manual

ID

Location in the EM&A Manual

Currently Situation

AM1

Tung Wah Group of Hospitals Aided Primary School & Secondary School

Not yet construct

AM2

Lohas Park Stage 2 (Planned Development in Area 86)

Under Construction

AM3

Lohas Park Stage 3 (Planned Development in Area 86)

Under Construction

 

Table 2-3           Designated Construction Noise Monitoring Location recommended by EM&A Manual

ID

Location

Currently Situation

CNMS-1

Lohas Park Stage 1(Planned Development in Area 86, Package 5) (Southeast facade)

Under Construction

CNMS-2

Lohas Park Stage 1 (Planned Development in Area 86, Package 6) (Southeast facade)

Under Construction

CNMS-3

Lohas Park Stage 3 (Planned Development in Area 86,Package 11) (West facade)

Under Construction

CNMS-4

Tung Wah Group of Hospitals Aided Primary School & Secondary School (Southwest facade)

Not yet construct

 

2.06          As observed and confirmed by ET and IEC during the joint site visit on 29th August 2018, the designated air quality and noise monitoring locations are under construction or yet to construct. It is considered that these designated locations are not appropriate to perform air quality and noise monitoring. In this regard, alternative locations were proposed as interim arrangement to carry out air quality and noise monitoring before occupation of the designated monitoring location. A letter enclosed with the alternative location proposal and IEC verification (Our Ref: TCS00975/18/300/L0038) was sent to EPD on 19th October 2018 and the proposal was agreed by EPD.

 

2.07          The agreed alternative monitoring locations for baseline monitoring was carried out are summarized in Table 2-4 and are shown in Appendix B.

Table 2-4           Proposed Alternative Monitoring Location

Location ID

Monitoring Parameter

Location

AM4

1-Hour TSP Air Quality

Podium of Lohas Park Phase 2A (Le Prestige)

AM5

24-Hour TSP Air Quality

Boundary of Site Office near Junction of Wan Po Road and Wan O Road

CNMS-5

Noise (Leq, L10 & L90)

Podium of Lohas Park Phase 2A (Le Prestige)

Remark: Since 24-Hour TSP Air Quality monitoring is not granted at AM4 Lohas Park Phase 2A, the 24-Hour TSP monitoring was therefore proposed at AM5 which is located at the boundary of the project site office.

 

Water Quality

2.08          According to Table 7.1 of the approved EM&A Manual Section 7.4, two Control Stations (C3 & C4), six (6) sensitive receivers (CC1, CC2, CC3, CC4, CC13 & SWI1) and one (1) Gradient station (I1) were recommended to perform water quality monitoring.  Details and coordinate of these water quality monitoring stations are described in Table 2-5 and the graphical layout plan is shown in Appendix B.

Table 2-5           Location of Water Quality Monitoring Station

Station

Coordinates

Description

Easting

Northing

CC1

843201

816416

Sensitive Receiver – Coral Sites at Chiu Keng Wan

CC2

844076

817091

Sensitive Receiver – Coral Sites at Junk Bay

CC3

844606

817941

Sensitive Receiver – Coral Sites at Junk Island

CC4

845444

815595

Sensitive Receiver – Coral Sites at Fat Tong Chau West

CC13

844200

817495

Sensitive Receiver – Coral Sites at Junk Bay near Chiu Keng Wan

SWI1

845512

817442

Sensitive ReceiverTseung Kwan O Salt Water Intake

C3

843821

816211

Control Station (Ebb Tide) – within Junk Bay

C4

844621

815770

Control Station (Flood Tide) – within Junk Bay

I1

844602

817675

Gradient Station – between LTT and CBL

 

2.09          According to the Hong Kong Tidal Stream Prediction System operated by the Marine Department, the marine water will flow into the Junk Bay and Kowloon Bay at Flood tide while will flow out from the Junk Bay and Kowloon Bay at Ebb tide. The upstream control station at Flood tide will be the Control Station C4 and at Ebb tide will be the Control Station C3. The tide pattern in Junk Bay at both ebb tide and flood tide was illustrated in Appendix J.

 

2.10          In case of exceedance was recorded, the results obtained from the upstream control station (C3 for ebb tide & C4 for flood tide) and the gradient station I1 will be used as appropriate to identify the source(s) of impact.

 

Monitoring Frequency and Period

2.11          The baseline monitoring should be conducted prior to commencement of the construction work under the Project.  No construction activities are allowed to be undertaken during the baseline monitoring period.  Frequency and duration of baseline monitoring programme including air quality, background noise and marine water quality were carried out in accordance with the approved EM&A Manual Sections 5.5.3, 6.4.1.1 and 7.5.1 and are listed as below:

 

Air Quality

2.12          Continuous 24-hour TSP monitoring and 3 times of 1-hour TSP monitoring at the available designated or alternative monitoring locations should be carried out daily for at least 14 consecutive days.

 

Background Noise

2.13          Continuous baseline noise monitoring of the A-weighted levels Leq, L10 and L90 should be carried out daily for a period of at least two weeks, with a sampling period of 30 minutes between 0700 and 1900 hours and 15 minutes (as three consecutive Leq(5min) readings) for evening time (between 1900 and 2300 hours on normal weekdays),  general holidays including Sundays (between 0700 and 2300 hours) and night-time (between 2300 and 0700 on all days).

 

Marine Water Quality

2.14          Marine water quality monitoring at the specified stations as shown in Table 2-5, should be conducted 3 days a week, at mid-flood and mid-ebb tides, for at least 4 weeks to prior commencement any marine construction activities such as the pile excavation works for the bridge pier foundations.  The intervals between 2 consecutive sets of monitoring should not less than 36 hours.

 

Monitoring Equipment

Air Quality Monitoring

2.15          The 24-hour and 1-hour TSP levels should be measured by following the standard high volume sampling method as set out in the Title 40 of the Code of Federal Regulations, Chapter 1 (Part 50), Appendix B.  If the ET proposes to use a direct reading dust meter to measure 1-hour TSP levels, sufficient information shall be submitted to the IEC to prove that the instrument is capable of achieving a comparable result to the HVAS.  The instrument should be calibrated regularly, and the 1-hour sampling shall be determined on yearly basis by the HVS to check the validity and accuracy of the results measured by direct reading method. The filter paper of 24-hour TSP measurement shall be determined by HOKLAS accredited laboratory.

 

Noise Monitoring

2.16          Sound level meter in compliance with the International Electrotechnical Commission Publications 651: 1979 (Type 1) and 804: 1985 (Type 1) specifications shall be used for carrying out the noise monitoring.  The sound level meter shall be checked using an acoustic calibrator.  The wind speed shall be checked with a portable wind speed meter capable of measuring the wind speed in ms-1.

 

Marine Water Quality Monitoring

2.17          For water quality monitoring, the equipment should fulfill the requirement under the Approved EM&A Manual Section 7.2.  The requirement is summarized below:

       Dissolved Oxygen and Temperature Measuring Equipment – The instrument should be a portable, weatherproof dissolved oxygen measuring instrument completed with cable, sensor, comprehensive operation manuals, and should be operable from a DC power source. It should be capable of measuring: dissolved oxygen levels in the range of 0-20 mg/L and 0-200% saturation; and a temperature of 0-45 degrees Celsius. It should have a membrane electrode with automatic temperature compensation complete with a cable of not less than 35 m in length. Sufficient stocks of spare electrodes and cable should be available for replacement where necessary.

       Turbidity Measurement Equipment – The instrument shall be a portable, weatherproof turbidity-measuring instrument complete with comprehensive operation manual. The equipment shall use a DC power source. It shall have a photoelectric sensor capable of measuring turbidity between 0-1000 NTU.

       Salinity Measurement Instrument – A portable salinometer capable of measuring salinity in the range of 0-40 ppm should be provided for measuring salinity of the water at each monitoring location.

       Water Depth Detector – A portable, battery-operated echo sounder should be used for the determination of water depth at each designated monitoring station. A detector affixed to the bottom of the works boat, if the same vessel is to be used throughout the monitoring programme, is preferred.

       Positioning Device – hand-held or boat-fixed type digital Global Positioning System (GPS) with way point bearing indication or other equipment instrument of similar accuracy, should be provided and used during water quality monitoring to ensure the monitoring vessel is at the correct location before taking measurements.

       Water Sampling Equipment – A water sampler, consisting of a transparent PVC or glass cylinder of not less than two liters, which can be effectively sealed with cups at both ends, should be used. The water sampler should have a positive latching system to keep it open and prevent premature closure until released by a messenger when the sampler is at the selected water depth.

 

Derivation of Action/Limit (A/L) Levels

2.18          The baseline results form the basis for determining the environmental acceptance criteria for the impact monitoring.  A summary of derivation of Action/Limit (A/L) Levels for air quality, construction noise and water quality are shown in Tables 2-6, 2-7 and 2-8 respectively.

 

Table 2-6           Derivation of Action and Limit Levels for Air Quality

Parameter

Action Level

Limit Level

24-hour TSP

For baseline level £ 200 mg/m3:

Action level = (Baseline × 1.3 + Limit level)/2

260 mg/m3

For baseline level > 200 mg/m3:

Action level = Limit level

1-hour TSP

For baseline level £ 384 mg/m3:

Action level = (Baseline × 1.3 + Limit level)/2

500 mg/m3

For baseline level > 384 mg/m3:

Action level = Limit level

 

Table 2-7           Derivation of Action and Limit Levels for Construction Noise

Time Period

Action Level in dB(A)

Limit Level in dB(A)

0700-1900 hours on normal weekdays

When one documented complaint is received

75* dB(A)

Note:            (*)      Reduces to 70 dB(A) for schools and 65 dB(A) during the school examination periods.

 

Table 2-8           Derivation of Action and Limit Levels for Water Quality

Parameter

Action Level

Limit Level

SS in mg/L

(depth-averaged)

(a) (c)(d)

CC1, CC2, CC3, CC4 and CC13

95%-ile of baseline data, or 120% of upstream control station at the same tide of the same day, whichever is higher.

 

SWI1 only

8mg/L

CC1, CC2, CC3, CC4 and CC13

99%-ile of baseline data, or 130% of upstream control station at the same tide of the same day, whichever is higher.

 

SWI1 only

10mg/L

DO in mg/L (b)

Surface and Middle

5%-ile of baseline data for surface and middle layer

Bottom

5%-ile of baseline data for bottom layers

Surface and Middle

4mg/L or 1%-ile of baseline for surface and middle layer

Bottom

2mg/L or 1%-ile of baseline data for bottom layer

Turbidity in NTU

(depth-averaged)

 (a) (c) (d)

CC1, CC2, CC3, CC4, CC13 and SWI1

95%-ile of baseline data, or 120% of upstream control station at the same tide of the same day, whichever is higher.

CC1, CC2, CC3, CC4, CC13 and SWI1

99%-ile of baseline data, or 130% of upstream control station at the same tide of the same day, whichever is higher.

Notes:

(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, in order to better utilize the baseline data in the derivation of water quality limit, the water quality limits were set as 95/99%-ile of baseline data OR 120/130% of upstream control station at the same tide of the same day, whichever is higher.

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

(b)        For SS at SWI1, the Action and Limit Level were set according the approved EM&A Manual based on the assessment criteria of the WSD salt water intake.

 

Event Action Plan

2.19          Should non-compliance of the environmental quality criteria occurs, remedial actions will be triggered according to the Event and Action Plan which presented in Appendix I.

 

 


3.0              Baseline monitoring methodology

General

3.01          Baseline monitoring of air quality, background noise and marine water quality were conducted from 21st September 2018 to 13th November 2018.  During the baseline monitoring period, no construction activities were carried out under the Project.

 

Location of Baseline Monitoring

Air Quality

3.02          Baseline air quality monitoring, 1-hour TSP measurement at AM4 from 30th October 2018 to 12th November 2018 and 24-hour TSP measurement at AM5 were undertaken from 30th October 2018 to 13th November 2018.  The monitoring locations of AM4 and AM5 were shown in Table 2-1 and Appendix B.

 

Background Noise

3.03          Baseline 24-Hour noise monitoring was undertaken at alternative location CNMS-5 from 29th October 2018 to 13th November 2018.  The location of CNMS-5 was shown in Table 2-2 and Appendix B.

 

Water Quality

3.04          Baseline marine water quality monitoring was undertaken at the all designated monitoring stations from 21st September 2018 to 22nd October 2018.  The detailed information of monitoring stations was shown in Tables 2-3 and Appendix B.

 

Monitoring Equipment of Baseline Monitoring

Air Quality

3.05          Equipment used for baseline air quality monitoring is listed in Table 3-1.

Table 3-1           Air Quality Monitoring Equipment

Equipment

Model

24-hour TSP

High Volume Air Sampler

TISCH High Volume Air Sampler, HVAS Model TE-5170

Calibration Kit

TISCH Model TE-5025A

1- hour TSP

Portable Dust Meter

Laser Dust Monitor Sibata LD-3B Laser Dust Monitor

 

Noise

3.06          Equipment used for baseline noise monitoring is listed in Table 3-2.

Table 3-2           Construction Noise Monitoring Equipment

Equipment

Model

Integrating Sound Level Meter

B&K Type 2238

Calibrator

B&K Type 4231

Portable Wind Speed Indicator

Anemometer AZ Instrument 8908

 

Water Quality

3.07          Equipment used for marine water quality monitoring proposed by ET was verified by IEC prior of baseline monitoring work commencement.  The detail of equipment used for baseline monitoring is listed in Table 3-3 as below.

Table 3-3           Water Monitoring Equipment

Equipment

Model

A Digital Global Positioning System

GPS12 Garmin

Water Depth Detector

Eagle Sonar CUDA 300

Water Sampler

A 2-litre transparent PVC cylinder with latex cups at both ends

Thermometer & DO meter

YSI ProDSS Digital Sampling System Water Quality Meter

pH meter

YSI ProDSS Digital Sampling System Water Quality Meter

Turbidimeter

YSI ProDSS Digital Sampling System Water Quality Meter

Salinometer

YSI ProDSS Digital Sampling System Water Quality Meter

Sample Container

High density polythene bottles (provided by laboratory)

Storage Container

‘Willow’ 33-litter plastic cool box with Ice pad

 

Monitoring Procedure

3.08          The procedures to conduct air quality, noise and marine water quality monitoring are summarized in following sub-sections.

 

Air Quality

1-hour TSP

3.09          Operation of the 1-hour TSP meter would be to follow manufacturer’s Operation and Service Manual.

 

3.10          The 1-hour TSP monitor, brand named “Model AM510 SidePakTM Personal Aerosol Monitor/ Sibata LD-3B Laser Dust monitor Particle Mass Profiler & Counter” is a portable, battery-operated laser photometer. The 1-hour TSP meter provides a real time 1-hour TSP measurement based on 900 light scattering. The 1-hour TSP monitor consists of the following:

a.         A pump to draw sample aerosol through the optic chamber where TSP is measured;

b.         A sheath air system to isolate the aerosol in the chamber to keep the optics clean for maximum reliability; and

c.          A built-in data logger compatible with Windows based programme to facilitate data collection, analysis and reporting.

 

24-hour TSP

3.11          The equipment used for 24-hour TSP measurement is the High Volume Air Sampler (hereinafter the “HVAS”) brand named TISCH, Model TE-5170 TSP High Volume Air Sampler, which complied with EPA Code of Federal Regulation, Appendix B to Part 50. The HVS consists of the following:

a.         An anodized aluminum shelter;

b.        A 8”x10” stainless steel filter holder;

c.         A blower motor assembly;

d.        A continuous flow/pressure recorder;

e.         A motor speed-voltage control/elapsed time indicator;

f.         A 6-day mechanical timer, and

g.         A power supply of 220v/50 Hz

 

3.12          For HVAS for 24-hour TSP monitoring, the HVAS is mounted in a metallic cage with a top for protection and is sat on the existing ground.  The flow rate of the HVAS between 0.6m3/min and 1.7m3/min would be properly set in accordance with the manufacturer’s instruction to within the range recommended in EPA Code of Federal Regulation, Appendix B to Part 50.  Glass Fiber Filter 8" x 10" of TE-653 would be used for 24-Hour TSP monitoring and would be supplied by laboratory.  The general procedures of sampling are described as below:-

Ÿ   A horizontal platform with appropriate support to secure the samples against gusty wind should be provided;

Ÿ   No two samplers should be placed less than 2 meters apart;

Ÿ   The distance between the sampler and an obstacle, such as building, must be at least twice the height that the obstacle protrudes above the sample;

Ÿ   A minimum of 2 meters of separation from any supporting structure, measured horizontally is required;

Ÿ   Before placing any filter media at the HVAS, the power supply should be checked to ensure the sampler work properly;

Ÿ   The filter paper should be set to align on the screen of HVAS to ensure that the gasket formed an air tight seal on the outer edges of the filter.  Then filter holder frame should be tightened to the filter hold with swing bolts.  The holding pressure should be sufficient to avoid air leakage at the edge.

Ÿ   The mechanical timer should be set for a sampling period of 24 hours (12:00 afternoon to 12:00 afternoon next day).  Information will be recorded on the field data sheet, which should included the sampling data, starting time, the weather condition at current and the filter paper ID with the initial weight;

Ÿ   After sampling, the filter paper should be collected and transfer from the filter holder of the HVAS to a sealed envelope and sent to a local HOKLAS accredited laboratory for quantifying.

 

3.13          All the sampled 24-hour TSP filters were kept in normal air conditioned room conditions, i.e. 70% HR (Relative Humidity) and 25oC, for six months prior to disposal.

 

3.14          The HVAS used for 24-hour TSP monitoring was calibrated before the commencement for sampling, with five-point calibration in accordance with the manufacturer’s instruction using the NIST-certified standard calibrator (Tisch Calibration Kit Model TE-5025A) to establish a relationship between the follow recorder meter reading in cfm (cubic feet per minute) and the standard flow rate, Qstd, in m3/min. 

 

Construction Noise

3.15          As referred to the Technical Memorandum (TM) issued under the NCO, sound level meters in compliance with the International Electrotechnical Commission Publications 651: 1979 (Type 1) and 804:1985 (Type 1) specifications should be used for carrying out the noise monitoring.

 

3.16          All noise measurements were performed with the meter set to FAST response and on the A-weighted equivalent continuous sound pressure level (Leq).  Throughout baseline monitoring period, 24-Hours continuous noise monitoring was conducted in order to obtained Leq(30min) and three sets of Leq(5min) measurements for the daytime (between 07:00-19:00 hours) and evening / mid-night (between 19:00-07:00 hours next day) respectively.

 

3.17          The sound level meter will be mounted on a tripod at a height of 1.2 m and placed at the assessment point and oriented such that the microphone is pointed to the site with the microphone facing perpendicular to the line of sight. The windshield would be fitted for all measurements. Where a measurement is to be carried out at a building, the assessment point would normally be at a position 1 m from the exterior of the building façade. Where a measurement is to be made for noise being received at a place other than a building, the assessment point would be at a position 1.2 m above the ground in a free-field situation, i.e. at least 3.5 m away from reflective surfaces such as adjacent buildings or walls.

 

3.18          Immediately prior to and following each noise measurement the accuracy of the sound level meter would be checked using an acoustic calibrator generating a known sound pressure level at a known frequency.  Measurement results would be accepted as valid only if internal check the used sound level meter at before and after the noise measurement to record as ±0.5dB of the known sound pressure level.

 

3.19          Noise measurements should not be made in fog, rain, wind with a steady speed exceeding 5m/s or wind with gusts exceeding 10m/s.  The wind speed would be checked with a portable wind speed meter capable of measuring the wind speed in m/s.

 

Marine Water Quality

3.20          Marine water quality monitoring was conducted at all designated locations in accordance with Table 7.1 of the approved EM&A Manual. The operating and analytical of sampling procedures are described as below:

Ÿ   A Global Positioning System (GPS) was used to ensure that the correct location was selected prior to sample collection.  A portable, battery-operated echo sounder was used for the determination of water depth at each designated monitoring station.

Ÿ   The marine water sampler was lowered into the water body at a predetermined depth. The trigger system of the sampler is activated with a messenger and opening ends of the sampler are closed accordingly then the sample of water is collected.

Ÿ   During the sampling, the sampling container was rinsed to use a portion of the marine water sample before the water sample is transferred to the container.  Upon sampling completion, the container was sealed with a screw cap.

Ÿ   Before the sampling process, general information such as the date and time of sampling, weather condition and tidal condition as well as the personnel responsible for the monitoring was recorded on the monitoring field data sheet.

Ÿ   In-situ measurement including water temperature, turbidity, dissolved oxygen, salinity, pH and water depth was recorded at the identified monitoring point.  At each station, marine water samples were collected at three depths: 1m below water surface, 1m above sea bottom and at mid-depth when the water depth exceeds 6m.  Samples at 1m below water surface and 1m above sea bottom were collected when the water depth is between 3m and 6m.  And samples at mid-depth was taken when the water depth is below 3m.

Ÿ   For the in-situ measurement, two consecutive measurements of sampling depth, temperature, dissolved oxygen, salinity, turbidity and pH concentration was measured at the sea. The YSI ProDSS Multifunctional Meter was retrieved out of the water after the first measurement and then re-deployed for the second measurement.  Where the difference in the value between the first and second readings of each set is more than 25% of the value of the first reading, the reading is discarded and further readings is taken.

Ÿ   Marine water sample was collected by using a water sampler. The high-density polythene bottles will be filled after the water sample collected from the sea.  Before the water sample being fill into the sampling bottles, the sampling bottles will be pre-rinsed with the same water sample.  The sampling bottles will then be packed in cool-boxes (cooled at 4OC without being frozen), and delivered to HOKLAS accredited laboratory for the chemical analysis as followed APHA Standard Methods for the Examination of Water and Wastewater 19ed 2540D, unless otherwise specified.

           

3.21          All marine water in-situ measurement equipment used are calibrated at three months interval. 

 

3.22          Before each round of monitoring, the dissolved oxygen probe was calibrated by wet bulb method; a zero check in distilled water was performed with the turbidity and salinity probes. The turbidity probe was checked with a standard solution of known NTU and known value of the pH standard solution were used to check the accuracy of pH value before each monitoring day.

 

Laboratory Analysis

3.23          All water samples included the duplicate samples, was tested with chemical analysis as specified in the EM&A Manual by a HOKALS accredited laboratory - ALS Technichem (HK) Pty Ltd.  The chemicals analysis method and reporting limit show Table 3-4.

Table 3-4           Testing Method and Reporting Limit of the Chemical Analysis

Parameter

ALS Method Code

In-house Method Reference (1)

Reporting Limit

Total Suspended Solids

EA025

APHA 2540D

1 mg/L

Note:

1.          The exact method shall depend on the laboratory accredited method. APHA = Standard Methods for the Examination of Water and Wastewater by the American Public Health Association.

 

3.24          The determination works was start within 24 hours after collection of the water samples or within the holding time as advised by the laboratory.

 

Meteorological Information

3.25          The meteorological information including wind direction, wind speed, humidity and temperature etc. during baseline monitoring was extracted from the closest Tseung Kwan O Hong Kong Observatory Station.  Moreover, the data of rainfall and air pressure were extracted from King’s Park Station.

 

3.26          For marine water quality monitoring, tidal information was referred to tide gauge at Tai Miu Wan.

 

Equipment Calibration

3.27          Valid calibration certificates of monitoring equipment/instruments including air, noise & water and the HOKLAS-Accreditation certificate of the testing laboratory respectively are attached in Appendix C.

 

Data Management and Data QA/QC Control

3.28          The baseline monitoring data were handled by the ET’s in-house data recording and management system.

 

3.29          The monitoring data recorded in the equipment were downloaded directly from the equipment at each monitoring day or after completion of baseline measurement.  The downloaded monitoring data were input into a computerized database properly maintained by the ET.  The laboratory results were input directly into the computerized database and checked by personnel other than those who input the data.

 

3.30          If monitoring parameters require laboratory analysis, the local laboratory would follow the QA/QC requirements as set out under the HOKLAS scheme for the relevant laboratory tests.

 

 


4.0              Baseline Monitoring Results

            General

4.01          The baseline monitoring schedules of air quality, background noise and marine water quality are presented in Appendix D and the monitoring results are detailed in the following sub-sections.

 

            Results of Air Quality Monitoring

4.02          Baseline 1-hour TSP from 30th October 2018 to 12th November 2018 and 24-hour TSP monitoring were carried out from 30th October 2018 to 13th November 2018.  The results for 1-hour and 24-hour TSP are summarized in Table 4-1.  The 24-hour TSP data are shown in Appendix E.

Table 4-1           Summary of 1-hour TSP and 24-Hr Monitoring Results – Alternative Monitoring Location AM4 (1-Hour TSP) and AM5 (24-Hour TSP)

AM5

AM4

24-hour TSP (mg/m3)

1-hour TSP (mg/m3)

Date

Meas. Result

Date

Start Time

1st Meas.

2nd Meas.

3rd Meas.

30-Oct-18

93

30-Oct-18

9:34

29

27

28

31-Oct-18

86

31-Oct-18

9:46

26

27

30

1-Nov-18

93

1-Nov-18

9:38

42

39

41

2-Nov-18

45

2-Nov-18

9:52

37

33

34

3-Nov-18

42

3-Nov-18

9:30

31

28

30

4-Nov-18

70

4-Nov-18

9:30

38

35

37

5-Nov-18

71

5-Nov-18

9:42

52

54

52

6-Nov-18

*

6-Nov-18

9:36

50

42

47

7-Nov-18

67

7-Nov-18

9:24

44

42

40

8-Nov-18

121

8-Nov-18

9:34

55

61

58

9-Nov-18

166

9-Nov-18

9:49

53

56

58

10-Nov-18

69

10-Nov-18

9:26

51

53

49

11-Nov-18

71

11-Nov-18

9:18

50

48

52

12-Nov-18

94

12-Nov-18

9:41

49

59

57

13-Nov-18

197

--

--

--

--

--

Average

(Range)

92

(42 – 197)

Average

(Range)

43

(26 – 61)

*24-Hour TSP failure due to power supply issue

 

Action/Limit Levels of Air Quality

4.03          Following the criteria shown in Table 2-6 of this report, the proposed Action and Limit Levels for 24-hour and 1-hour TSP are listed in Table 4-2.

Table 4-2           Action and Limit Levels for Air Quality Monitoring

Monitoring Station

Action Level (mg /m3)

Limit Level (mg/m3)

1-hour TSP

24-hour TSP

1-hour TSP

24-hour TSP

AM4

278

NA

500

NA

AM5

NA

190

NA

260

Note: 1-hour & 24-hour TSP Action Level = (Average Baseline Result × 1.3 + Limit level)/2

 

Results of Background Noise Monitoring

4.04          The baseline continuous noise monitoring was undertaken from 29th October 2018 to 13th November 2018.  The measurement data are shown in Appendix F and summarized in Table 4-3.

Table 4-3           Summaries of Noise Monitoring Results – Alternative Monitoring Location CNMS-5

Time Period

Mean

Max

Min

Normal Daytime 0700-1900 – Leq(30min)

64.7

69.4

59.7

Restricted Hours 0700-1900 holiday – Leq(30min)

60.7

68.1

56.6

Restricted Hours 1900-2300 – Leq(15min)

59.4

65.7

55.6

Restricted Hours 2300-0700 next day – Leq(15min)

56.1

62.2

53.2

Remark: The sound meter was set up at the Podium of Lohas Park Phase 2A (Le Prestige) with 1m façade

 

Action/ Limit Levels of Construction Noise

4.05          According to the criteria shown in Table 2-7 of this report, the proposed Action/Limit levels of construction noise monitoring station are illustrated in Table 4-4.

Table 4-4           Action / Limit Levels of Construction Noise Monitoring

Monitoring Location

Action Level

Limit Level

(Leq30min)

Time Period: 0700-1900 hours on normal weekdays

CNMS-5

When one or more documented complaints are received

75 dB(A)

Remarks:

If works are to be carried out during restricted hours, the conditions stipulated in the construction noise permit issued by the Noise Control Authority have to be followed.

 

4.06          Since the designated locations CNMS-1, CNMS-2, CNMS-3 and CNMS-4 are currently unavailable to carry out noise monitoring, the construction noise monitoring will be resumed at these designated monitoring locations once they are available.  Limit Level of 75dB(A) will be adopted for the impact noise monitoring at CNMS-1, CNMS-2 & CNMS-3.  For designated location CNMS-4 which is located at planned school, Limit Level of 70dB(A) for normal school day and Limit Level of 65dB(A) for examination period will be adopted for the impact noise monitoring when the school is occupied.

 

Results of Marine Water Quality Monitoring

4.07          Four weeks of baseline water quality monitoring at nine (9) designated monitoring stations were performed as between 21st September 2018 and 22nd October 2018.  The summary of water depth recorded at each designated monitoring station presents in Table 4-5.

Table 4-5           Water Depths of Water Quality Monitoring Stations Summary

Monitoring Station

Status

Water Depth, (m)

Co-ordnance

Min

Max

Ave.

East

North

CC1

Sensitive Receiver

6.4

9.3

8.0

843201

816416

CC2

Sensitive Receiver

11

13.1

12.0

844076

817091

CC3

Sensitive Receiver

8.6

9.9

9.1

844606

817941

CC4

Sensitive Receiver

1.6

4.3

2.7

845444

815595

CC13

Sensitive Receiver

7.2

8.9

7.9

844200

817495

SWI1

Sensitive Receiver

3.6

4.9

4.1

845512

817442

C3

Control Station – Ebb Tide

14.2

16.4

15.4

843821

816211

C4

Control Station – Flood Tide

14.8

17

16.2

844621

815770

I1

Gradient Station

9.3

10.7

9.9

844602

817675

 

4.08          In-situ measurements results including “Dissolved Oxygen” and “Turbidity” are summarized in Tables 4-6.  Detailed monitoring results of in-situ measurements are shown in Appendix G.

Table 4-6           Summaries of Marine Water In-situ Measurement Results

Summary of Results Conditions

CC1

CC2

CC3

CC4

CC13

SWI1

C3

C4

I1

Dissolved Oxygen – Depth Average of Surface & Mid-depth (mg/L)

5%-ile

5.8

5.8

5.5

5.7

5.6

5.4

N/A

N/A

N/A

1%-ile

5.7

5.7

5.4

5.7

5.5

4.8

N/A

N/A

N/A

Average

6.5

6.3

6.3

6.2

6.2

6.2

6.2

6.2

6.2

Min

5.7

5.6

5.4

5.7

5.5

4.7

5.6

5.6

5.7

Max

8.2

7.6

7.9

7.0

7.4

9.5

7.5

7.5

7.5

Dissolved Oxygen – Bottom Depth (mg/L)

5%-ile

5.3

5.3

4.9

5.5

5.3

5.1

N/A

N/A

N/A

1%-ile

5.2

5.1

4.7

5.4

5.2

5.0

N/A

N/A

N/A

Average

6.0

5.8

5.5

5.9

5.7

5.9

5.8

5.8

5.6

Min

5.2

5.0

4.6

5.4

5.2

5.0

5.1

5.1

4.9

Max

6.8

6.4

6.2

6.8

6.3

7.5

6.4

6.4

6.5

Turbidity – Depth Average (NTU)

95%-ile

5.8

4.6

4.8

6.1

6.0

6.1

N/A

N/A

N/A

99%-ile

6.0

5.5

5.4

7.1

6.3

7.1

N/A

N/A

N/A

Average

3.5

3.3

3.4

4.5

3.9

3.9

4.2

3.9

3.5

Min

1.9

1.8

1.9

2.9

2.2

2.2

2.5

2.5

1.8

Max

6.0

5.8

5.6

7.3

6.3

7.3

6.5

6.3

5.6

N/A: Not applicable

 

4.09          Laboratory analysis result of “Suspended Solids (SS)” is summarized in Tables 4-7.  Laboratory data reports are shown in Appendix G.

Table 4-7           Summaries of Suspended Solids Analysis Results

Summary of Results Conditions

CC1

CC2

CC3

CC4

CC13

SWI1

C3

C4

I1

Suspended Solids – Depth Average (mg/L)

95%-ile

7.8

9.0

8.2

13.8

8.9

12.3

N/A

N/A

N/A

99%-ile

9.3

9.2

9.0

15.4

10.3

15.8

N/A

N/A

N/A

Average

5.5

5.2

4.5

7.5

6.0

6.7

6.2

6.0

5.0

Min

1.7

1.3

1.0

3.0

1.9

2.0

2.4

1.8

1.0

Max

9.8

9.2

9.2

15.8

10.8

16.8

9.3

8.8

9.9

N/A: Not applicable

Remark: SS result of SWI1 Mid-Flood Bottom on 26 Sep 2018 and of CC13 Mid-Ebb Bottom on 22 Oct 2018 were discarded from the calculation due to abnormal high result obtained.

 

            Discussion and Recommendation

Possible Influence of Seasonal Changes

4.10          The baseline air quality monitoring was conducted from 30th October 2018 to 13th November 2018 which most of the monitoring were conducted during Hong Kong dry seasons.  The baseline data collected therefore represent the baseline air quality of the dry season immediately prior to commencement of the Project.  The data obtained may not reflect the air quality conditions of wet seasons in Hong Kong which are normally different.

 

4.11          The baseline marine quality monitoring was conducted from 21st September 2018 to 22nd October 2018 which reflect typical water quality at the monitoring locations during wet seasons (April to October). The baseline DO, SS and turbidity conditions at the monitoring locations may differ from dry season especially during rainy days and in particular under high tide flow conditions.

 

Possible Influence of Other Construction Projects

4.12          During the air quality and noise baseline monitoring at interim alternative monitoring locations, there are other on-going construction works carried out nearby (e.g. at the designated air and noise monitoring locations) which may influence the baseline and impact monitoring at the interim alternative monitoring location.

 

4.13          Therefore, it is recommended to regularly review the air quality and marine water quality baseline conditions, in particular during season changes and after the designated monitoring locations are occupied.  The environmental performance criteria may need to be re-established if it is evident that the baseline conditions have changed significantly.  An updated baseline data should then be sought for re-establishment of the updated environmental performance criteria for Event and Action Plan to be smoothly implemented.

 


 

5.0              Conclusions and Recommentations

Conclusions

5.01          The baseline air quality, noise and marine water monitoring were undertaken during the period from 21st September 2018 to 13th November 2018 at the agreed monitoring location.  During the baseline monitoring, there were no construction activities undertaken under this Project.

 

5.02          Based on the baseline monitoring results, the recommended environmental performance criteria for air quality, construction noise and water quality are summarized as follows:

 

Recommended Action & Limit Levels of Air Quality

Monitoring Station

Action Level (mg /m3)

Limit Level (mg/m3)

1-hour TSP

24-hour TSP

1-hour TSP

24-hour TSP

Alternative Location – Lohas Park Phase 2A (AM4)

278

NA

500

NA

Interim Alternative Location – the Project site office (AM5)

NA

190

NA

260

Remarks: Air quality monitoring will be resumed at the designated locations AM1, AM2 and AM3 once they are available and permission are granted.

 

Recommended Action & Limit Levels of Construction Noise

Monitoring Location

Action Level

Limit Level in dB(A)

(Leq30min)

Time Period: 0700-1900 hours on normal weekdays

Alternative Location – Lohas Park Phase 2A (CNMS-5)

When one or more documented complaints to be received

75

Remarks:

(i)          Construction noise monitoring will be resumed at the designated locations CNMS-1, CNMS-2, CNMS-3 and CNMS4 once they are available and permission are granted;

(ii)        The designated locations CNMS-1, CNMS-2 and CNMS-3 are residential building which are still under construction, Limit Level of 75dB(A) will be adopted until they are occupied;

(iii)      The designated location CNMS-4 is located at planned school and still not yet to construction.  When the school occupied and operated, Limit Level of 70dB(A) should be adopted and should be reduced to 65dB(A) during examination period; and

(iv)       If construction works are required during restricted hours, the conditions stipulated in the construction noise permit issued by the Noise Control Authority shall be followed.

 

Monitoring Station

Depth Average of SS (mg/L)

Action Level

Limit Level

CC1

7.8

OR 120% of upstream control station at the same tide of the same day

(Control Station C3 at Ebb tide and Control Station C4 at Flood tide), whichever is higher

9.3

OR 130% of upstream control station at the same tide of the same day

(Control Station C3 at Ebb tide and Control Station C4 at Flood tide) , whichever is higher

CC2

9.0

9.2

CC3

8.2

9.0

CC4

13.8

15.4

CC13

8.9

10.3

SWI1

8 mg/L

10 mg/L

 



Monitoring Location

Dissolved Oxygen (mg/L)

Depth Average of Surface and Mid-depth

Bottom

Action Level

Limit Level

Action Level

Limit Level

CC1

5.8

5.7

5.3

5.2

CC2

5.8

5.7

5.3

5.1

CC3

5.5

5.4

4.9

4.7

CC4

5.7

5.7

5.5

5.4

CC13

5.6

5.5

5.3

5.2

SWI1

5.4

4.8

5.1

5.0

Monitoring Location

Depth Average of Turbidity (NTU)

Action Level

Limit Level

CC1

5.8

OR 120% of upstream control station at the same tide of the same day

(Control Station C3 at Ebb tide and Control Station C4 at Flood tide) , whichever is higher

6.0

OR 130% of upstream control station at the same tide of the same day

(Control Station C3 at Ebb tide and Control Station C4 at Flood tide) , whichever is higher

CC2

4.6

5.5

CC3

4.8

5.4

CC4

6.1

7.1

CC13

6.0

6.3

SWI1

6.1

7.1

Notes:

(a)       For DO, non-compliance of water quality limits occurs when monitoring result is lower than the limits

(b)       For SS and turbidity, in order to better utilize the baseline data in the derivation of water quality limit, the water quality limits were set as 95/99%-ile of baseline data OR 120/130% of upstream control station at the same tide of the same day, whichever is higher.

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

(d)       For SS at SWI1, the Action and Limit Level were set according the approved EM&A Manual based on the assessment criteria of the WSD salt water intake.

 

 

Recommendations

 

5.03          The baseline air quality and noise monitoring was conducted during dry season (November to March) while baseline marine water quality was conducted during typical wet season (April to October) in Hong Kong. It is important to note that influence of seasonal changes should be taken into account when interpreting monitoring data obtained.

 

5.04          In addition, since some of the designated air and noise monitoring locations located near the interim alternative air and noise monitoring locations are still under construction, the baseline air quality and noise monitoring conducted may be influenced by the construction work carried out nearby.

 

5.05          Review of the baseline conditions may need to be conducted regularly, in particular during seasonal changes. If the changes in baseline conditions are evident, the environmental performance criteria should be re-established by agreement of the ER and IEC and submitted for EPD endorsement.