TABLE OF CONTENTS

 

EXECUTIVE SUMMARY

1.         INTRODUCTION

Background

Scope of Report

Project Organization

Summary of Construction Works

Summary of EM&A Programme Requirements

2.         AIR QUALITY

Monitoring Requirements

Monitoring Equipment

Monitoring Parameters, Frequency and Duration

Monitoring Locations

Monitoring Methodology

Monitoring Results

3.         NOISE MONITORING

Monitoring Requirements

Monitoring Equipment

Monitoring Locations

Monitoring Parameters

Monitoring Methodology

Monitoring Results

4.         VEGETATION MONITORING

Monitoring Requirement

Monitoring Location

Monitoring Methodology

Monitoring Results

Monitoring Requirement

6.         ENVIRONMENTAL SITE INSPECTION AND AUDIT

Site Inspection

Assessment of Environmental Monitoring Results

Advice on the Solid and Liquid Waste Management Status

Environmental Licenses and Permits

Implementation Status of Environmental Mitigation Measures

Summary of Exceedances of the Environmental Quality Performance Limit

Summary of Complaints, Notification of Summons and Successful Prosecutions

7.         FUTURE KEY ISSUES

Construction Programme for the Coming Months

Key Issues for Coming Month

Monitoring Schedule for the Coming Months

8.         CONCLUSIONS AND RECOMMENDATIONS

Conclusions

Recommendations

 

List of Tables

 

Table 1.1           Contact Information of Key Personnel

Table 2.1           Air Quality Monitoring Equipment

Table 2.2           Air Quality Monitoring Parameters, Frequency and Duration

Table 2.3           Locations of Air Quality Monitoring Stations

Table 2.4           Summary of 1-hour TSP Monitoring Results in the Reporting Period

Table 2.5           Summary of 24-hour TSP Monitoring Results in the Reporting Period

Table 3.1           Noise Monitoring Equipment

Table 3.2           Locations of Noise Monitoring Stations

Table 3.3           Summary of Noise Monitoring Results in the Reporting Period

Table 6.1           Summary of Environmental Licensing and Permit Status

 

List of Figures

 

Figure 1.1          Site Layout Plan

Figure 2.1          Locations of Air Quality and Noise Monitoring Stations

Figure 4.1          Damage to Root System of Tree No. T247

Figure 6.1          Environmental Complaint Handling Procedures    

 

List of Appendices

 

Appendix A        Project Organization Structure

Appendix B       Construction Programme

Appendix C       Implementation Schedule of Mitigation Measures (EMIS)

Appendix D       Action and Limit Levels for Air Quality  and Noise

Appendix E       Calibration Certificates

Appendix F        Air Quality Monitoring Results and Graphical Presentation

Appendix G       Event Action Plan

Appendix H       Weather Data

Appendix I         Noise Monitoring Results and Graphical Presentation

Appendix J        Detailed Landscape and Visual Monitoring Report

Appendix K       ET’s Site Inspection Summaries

Appendix L        Monitoring Schedules

 


 

 


EXECUTIVE SUMMARY

The Project “Landslide Preventive Works at Po Shan, Mid-levels – Design and Construction (Natural Terrain Risk Mitigation Works)” (hereafter called “the Project”) includes the installation of about 700 numbers of soil nails and about 60 numbers of raking drains on the natural terrain within the concerned area.

China State – China Railway Joint Venture (CCJV) was commissioned as the Contractor of the Project. ENSR Asia (HK) Ltd. was employed by CCJV as the Environmental Team to carry out the EM&A programme.

The impact environmental monitoring and audit for the Project includes the air quality, noise, ecology, landscape and visual monitoring. The construction of the Project and the EM&A programme commenced on 1 April 2008.

This report documented the findings of EM&A works conducted in the period between 1 and 31 July 2008. As informed by the Contractor, construction activity in the reporting period was:

-          Soil nail installation at Portion A1.

Breaches of Action and Limit Levels

There was no action / limit level exceedance recorded for 1-hour and 24-hour TSP monitoring.

In the reporting month, all noise level recorded complied with the limit level.

Complaint, Notification of Summons and Successful Prosecution

There was no complaint, notification of summons and successful prosecution received in the reporting month.

Reporting Change

There was no reporting change required in the reporting month.

Future Key Issues

The weather in the forthcoming month is expected to be wet and windy. The Contractor should provide preventive measures to prevent any muddy runoff, such as proper collection and treatment of the runoff and provide a functional temporary drainage system in site.

It is also recommended to implement all necessary preventive measures to avoid oil leakage on ground / soil, such as provision of drip trays for all oil drums / chemical containers. In the event of oil leakage, the Contractor should properly remove the contaminated soil and dispose of as chemical waste. Construction waste and general refuse should be properly collected and disposed of.

 

 


1.      INTRODUCTION

Background

1.1               The project site is located at the mostly undeveloped hillside above the residential development at Po Shan Road and adjacent to the trimmed back slope on the site of the catastrophic 1972 Po Shan Road failure. Previous studies had been carried out and results indicated that the natural hillside above Po Shan Road is affected by high groundwater level and unfavourable geology. Sub-surface drainage measures by means of sub-horizontal drains had been installed in 1984-85. These measures have been successful in lowering the main ground water table, thus improving the stability of the slopes such that large-scale failure have not occurred in the last twenty years.

 

1.2               The objective of the Project “Landslide Preventive Works at Po Shan, Mid-levels – Design and Construction (Natural Terrain Risk Mitigation Works)” under Contract CE 28/2004 (GE) is to carry out detailed design and supervision of landslide preventive works on local repair of the hillside to minimize slope deterioration and shallow instability.

 

1.3               The proposed landslide preventive works would be constructed to protect the existing residential developments at the toe of the project site.

 

1.4               The scope of works of this Project includes the installation about 700 numbers of soil nails and about 60 numbers of raking drains on the natural terrain within the concerned area. The length of the soil nails is about 20m with a spacing of 2m horizontally and 3m vertically; the length of raking drains is about 10m with a spacing of 5m horizontally and 15m vertically.

 

1.5               The Project is anticipated to complete in 10 months after the commencement of construction.

 

1.6               According to the Environmental Permit (EP-235/2005/B) and the EM&A Manual of the Project, there is a need of an EM&A programme including air quality, noise, ecology, and landscape and visual monitoring.

 

1.7               ENSR Asia (HK) Ltd. (ENSR) was employed by the Contractor, China State – China Railway Joint Venture, as the Environmental Team (ET) to undertake the Environmental Monitoring and Audit (EM&A) works for the Project. In accordance with the EM&A Manual of the Project, environmental monitoring of air quality, noise, ecology, landscape and visual and environmental site inspections would be required for this Project.

Scope of Report

1.8               This is the fourth monthly Environmental Monitoring and Audit (EM&A) Report under the Contract CE 28/2004 (GE) – Landslide Preventive Works at Po Shan Road, Mid-Levels – Design and Construction (Natural Terrain Risk Mitigation Works). This report presented a summary of the environmental monitoring and audit works, list of activities, and mitigation measures proposed by the ET for the Project in July 2008.

Project Organization

1.9               The project organization is shown in Appendix A. The key personnel contact names and numbers are summarized in Table 1.1

.

 

 

 

 

 

 

 

 

 

Table 1.1      Contact Information of Key Personnel

Party

Position

Name

Telephone

Fax

CEDD

Senior Engineer

H. W. Sun

2762 5375

2714 0247

ER (MGS)

Resident Engineer

Andrew J. Westmoreland

3188 0400

3188 0775

Assistant Resident Engineer

S. F. Chau

3188 0400

3188 0775

IEC (ENVIRON)

Independent Environmental Checker

David Yeung

3743 0788

3548 6988

Contractor (CCJV)

Project Manager

Eddie Tang

3188 0538

3188 1710

Safety and Environmental Officer

Ken Fong

3188 0538

3188 1710

ET (ENSR)

ET Leader

Alex Chan

3105 8525

2891 0305

 

Summary of Construction Works

1.10            The Contactor has carried out major activities in the reporting month. Details of the works undertaken in this reporting period are listed below:

 

-          Soil nail installation at Portion A1.

 

1.11            The general layout plan of the Project site showing the contract area is shown in Figure 1.1. The construction programme is provided in Appendix B.

 

1.12            The mitigation measures implementation schedule are presented in Appendix C.

 

Summary of EM&A Programme Requirements

1.13            The EM&A programme required environmental monitoring for air quality, noise, ecology and landscape and visual and environmental site inspections for air quality, noise, ecology, landscape and visual and waste management. The EM&A requirements for each parameter described in the following sections include:

 

-          All monitoring parameters;

-          Monitoring schedules for the reporting month and forthcoming months;

-          Action and Limit levels for all environmental parameters;

-          Event / Action Plan;

-          Environmental mitigation measures, as recommended in the Project EIA study final report; and

-          Environmental requirement in contract documents.

 

 


2.       AIR QUALITY

Monitoring Requirements

2.1               In accordance with the EM&A Manual, 1-hour and 24-hour TSP levels at 2 air quality monitoring stations were established. Impact 1-hour and 24-hour TSP monitoring was conducted for at least once every 7 days during the construction phase of the Project. The Action and Limit level of the air quality monitoring is provided in Appendix D.

Monitoring Equipment

2.2               24-hour TSP air quality monitoring was performed using High Volume Sampler (HVS) located at each designated monitoring station. The HVS meets all the requirements of the EM&A Manual. Portable direct reading dust meters were used to carry out the 1-hour TSP monitoring. Table 2.1 summarises the equipment used.

 

Table 2.1      Air Quality Monitoring Equipment

Equipment

Model

High Volume Sampler

GS 2310 Accu-vol system

Calibrator

GMW 25

1-hour TSP Dust Meter

Laser Dust Monitor – Model LD-3

 

Monitoring Parameters, Frequency and Duration

2.3               Table 2.2 summarizes the monitoring parameters, frequency and duration of impact TSP monitoring.

 

Table 2.2      Air Quality Monitoring Parameters, Frequency and Duration

Monitoring Station

Parameter

Frequency and Duration

CA1 & CA2

24-hour TSP

At least once every 7 days

1-hour TSP

At least 3 times every 7 days

Monitoring Locations

2.4               Both monitoring stations were set up at the proposed locations in accordance with EM&A Manual. Table 2.3 describes details of the two monitoring stations. The monitoring locations are shown in Figure 2.1.

 

Table 2.3      Locations of Air Quality Monitoring Stations

Monitoring Station

Identity / Description

CA1

Access road to Po Shan Mansions

CA2

Podium of Hamilton Court

 

 

 

 

 

Monitoring Methodology

24-hour TSP Monitoring

 

Installation

 

2.5               The HVS was installed in the vicinity of the air sensitive receivers.  The following criteria were considered in the installation of the HVS.

·         A horizontal platform with appropriate support to secure the sampler against gusty wind was provided.

·         The distance between the HVS and any obstacles, such as buildings, was at least twice the height that the obstacle protrudes above the HVS.

·         A minimum of 2 meters separation from walls, parapets and penthouse was required for rooftop sampler.

·         No furnace or incinerator flues were nearby.

·         Airflow around the sampler was unrestricted.

·         Permission was obtained to set up the samplers and to obtain access to the monitoring stations.

·         A secured supply of electricity is needed to operate the samplers.

 

Preparation of Filter Papers

 

·         Glass fibre filters, G810 were labeled and sufficient filters that were clean and without pinholes were selected.

·         All filters were equilibrated in the conditioning environment for 24 hours before weighing.  The conditioning environment temperature was around 25 °C and not variable by more than ±3 °C; the relative humidity (RH) was < 50% and not variable by more than ±5%.  A convenient working RH was 40%.

·         ALS Technichem (HK) Pty Ltd. has comprehensive quality assurance and quality control programmes.

 

Field Monitoring

 

·         The power supply was checked to ensure the HVS works properly.

·         The filter holder and the area surrounding the filter were cleaned.

·         The filter holder was removed by loosening the four bolts and a new filter, with stamped number upward, on a supporting screen was aligned carefully.

·         The filter was properly aligned on the screen so that the gasket formed an airtight seal on the outer edges of the filter.

·         The swing bolts were fastened to hold the filter holder down to the frame.  The pressure applied should be sufficient to avoid air leakage at the edges.

·         Then the shelter lid was closed and was secured with the aluminum strip.

·         The HVS was warmed-up for about 5 minutes to establish run-temperature conditions.

·         A new flowrate record sheet was set into the flow recorder.

·         The range specified in the EM&A Manual was between 0.6-1.7 m3/min.

·         The programmable timer was set for a sampling period of 24 hrs + 1 hr, and the starting time, weather condition and the filter number were recorded.

·         The initial elapsed time was recorded.

·         At the end of sampling, the sampled filter was removed carefully and folded in half length so that only surfaces with collected particulate matter were in contact.

·         It was then placed in a clean plastic envelope and sealed.

·         All monitoring information was recorded on a standard data sheet.

·         Filters were sent to ALS Technichem (HK) Pty Ltd.  for analysis.

 

Maintenance and Calibration

 

·         The HVS and its accessories are maintained in good working condition, such as replacing motor brushes routinely and checking electrical wiring to ensure a continuous power supply.

·         HVSs are calibrated using GMW-25 Calibration Kit prior to the commencement of baseline air quality monitoring, and will be calibrated at bi-monthly intervals throughout all stages of the impact monitoring.

·         Calibration records are shown in Appendix E.

 

1-hour TSP Monitoring

 

Measuring Procedures

 

2.6               The measuring procedures of the 1-hour dust meter are in accordance with the Manufacturer’s Instruction Manual as follows:

·        Set POWER to “ON”, push BATTERY button, make sure that the meter’s indicator is in the range with a red line and allow the instrument to stand for about 3 minutes (Then, the air sampling inlet has been capped).

·        Push the knob at MEASURE position.

·        Push “O-ADJ” button. (Then meter’s indication is 0).

·        Push the knob at SENSI ADJ position and set the meter’s indication to S value described on the Test Report using the trimmer for SENSI ADJ.

·        Pull out the knob and return it to MEASURE position.

·        Push “START” button.

 

Maintenance and Calibration

 

·        The 1-hour TSP meter would be checked at 3-month intervals and calibrated at 1-year intervals throughout all stages of the air quality baseline monitoring. Calibration records are shown in Appendix E.

Monitoring Results

2.7               The monitoring results for 1-hour TSP and 24-hour TSP are summarized in Table 2.4 and 2.5 respectively and the monitoring results are provided in Appendix F.

 

Table 2.4      Summary of 1-hour TSP Monitoring Results in the Reporting Period

 

Average (mg/m3)

Range (mg/m3)

Action Level  (mg/m3)

Limit Level (mg/m3)

CA1

70.8

59.0 – 80.2

309.3

500

CA2

69.5

56.7 – 80.6

319.6

500

 

Table 2.5      Summary of 24-hour TSP Monitoring Results in the Reporting Period

 

Average (mg/m3)

Range (mg/m3)

Action Level  (mg/m3)

Limit Level (mg/m3)

CA1

34.8

24.0 – 61.2

166.8

260

CA2

23.1

9.4 – 52.7

187.0

260

 

2.8               Air quality monitoring was carried out for both 1-hour TSP and 24-hour TSP at all the monitoring stations in the reporting month.

 

2.9               The air quality monitoring results, in terms of 1-hour TSP and 24-hour TSP, were below the action and limit level at both monitoring locations in the reporting month. The event action plan is annexed in Appendix G.

 

2.10            Weather information including wind speed and wind direction is annexed in Appendix H. The information was obtained from Hong Kong Observatory Victoria Peak Automatic Weather Station and Central Pier Anemometer Station.


3.      NOISE MONITORING

Monitoring Requirements

3.1               In accordance with the EM&A Manual, impact noise levels should be obtained at 2 noise monitoring stations. Impact noise monitoring was conducted for at least once per week during the construction phase of the Project. The Action and Limit level of the noise monitoring is provided in Appendix D.

Monitoring Equipment

3.2               Integrating Sound Level Meter was employed for noise monitoring.  They were Type 1 sound level meters capable of giving a continuous readout of the noise level readings including equivalent continuous sound pressure level (Leq) and percentile sound pressure level (Lx). They comply with International Electrotechnical Commission Publications 651:1979 (Type 1) and 804:1985 (Type 1).  Portable electronic wind speed indicator capable of measuring wind speed in m/s was employed to check the wind speed.  Table 3.1 details the noise monitoring equipment used.

 

Table 3.1      Noise Monitoring Equipment

Equipment

Model

Integrating Sound Level Meter

Rion NL-31

Calibrator

Rion NC-73

Monitoring Locations

3.3               Two monitoring stations were set up in accordance with EM&A Manual. Table 3.2 describes details of the two monitoring stations. The monitoring locations are shown in Figure 2.1.

 

Table 3.2      Locations of Noise Monitoring Stations

Monitoring Station

Identity / Description

CN1

Block A, Po Shan Mansions

CN2

Block A, Po Shan Mansions

Monitoring Parameters

3.4               One set of 30-mins measurement at each monitoring station between 0700 and 1900 on normal weekdays at a frequency of once per week was required to determine the impact noise level. Leq, L10 and L90 would be recorded.

Monitoring Methodology

Monitoring Procedures

·         The Sound Level Meter was set on a tripod at a height of 1.2 m above the ground.

·         Façade measurements were made at all three monitoring locations.

·         The battery condition was checked to ensure the correct functioning of the meter.

·         Parameters such as frequency weighting, the time weighting and the measurement time were set as follows:

-         frequency weighting: A

-         time weighting: Fast

-         time measurement: Leq(30 minutes) during non-restricted hours i.e. between 07:00 and 19:00 on normal weekdays

·         Prior to and after each noise measurement, the meter was calibrated using a Calibrator for 94 dB at 1000 Hz.  If the difference in the calibration level before and after measurement was more than 1 dB(A), the measurement would be considered invalid and repeat of noise measurement would be required after re-calibration or repair of the equipment.

·         The wind speed was frequently checked with a portable wind meter.

·         During the monitoring period, the Leq , L10 and L90 were recorded.  In addition, site conditions and noise sources were recorded on a standard record sheet.

·         Noise measurement was paused during periods of high intrusive noise (e.g. dog barking, helicopter noise) if possible. Observations were recorded when intrusive noise was unavoidable.

·         Noise monitoring was cancelled in the presence of fog, rain, wind with a steady speed exceeding 5 m/s, or wind with gusts exceeding 10 m/s.

Maintenance and Calibration

·         The microphone head of the sound level meter and calibrator is cleaned with soft cloth at quarterly intervals.

·         The meter should be checked and calibrated at yearly intervals.

·         Calibration details for the sound level meter and calibrator are provided in Appendix E.

Monitoring Results

3.5               The monitoring results for noise are summarized in Table 3.3 and the monitoring data is provided in Appendix I.

 

Table 3.3      Summary of Noise Monitoring Results in the Reporting Period

 

Average, dB(A), Leq (30 mins)

Range, dB(A), Leq (30 mins)

Limit Level, dB(A), Leq (30 mins)

CN1

60.7

58.6 – 61.9

75.0

CN2

59.5

56.9 – 61.1

75.0

 

3.6               There was no noise complaint received in the reporting month, hence, no action level exceedance was recorded. At both monitoring locations, CN1 and CN2, all the monitoring results (daytime) were below the limit level of 75 dB(A).

 

3.7               All the monitoring results lied within the range of the predicted noise levels in the EIA report.

 

3.8               Major noise sources during the noise monitoring included the construction activities from the Project and another project under the same contract (concurrent project) carried out in the vicinity and nearby traffic noise.

 

 


4.      VEGETATION MONITORING

Monitoring Requirement

4.1               As required under Environmental Permit No. EP-235/2005/B, the Permit Holder is required to carry out monitoring of the plant species of conservation interest to check on the health and condition of the plants twice a month during the construction period of the Project.

 

4.2               It is required to undertake the ecological tasks to fulfill the requirements of the Environmental Permit (EP).  As required by Conditions 2.11 and 3.5 of the EP, a suitably qualified ecologist with 7 or more years of relevant experience shall be employed to conduct the ecological monitoring.

 

Monitoring Location

4.3               The ecological monitoring was carried out for plant individuals of conservation interest identified within the proposed works area.

 

Monitoring Methodology

4.4               The ecological monitoring was conducted twice in the reporting month on 22 and 29 July 2008 by Ms. Gigi C C Lam, who had over 7 years of relevant ecological experience.

 

4.5               The plants of conservation interest, which were tagged during the baseline survey, were checked during each monitoring.

 

Monitoring Results

4.6               Soil nailing scaffolding works were in progress during the monitoring visits.  A total of 13 plant species of conservation interest (i.e. V001 to V013) were identified within the above works area during an earlier Detailed Vegetation Survey conducted under this Project.  The tagged vegetation was found to be in good condition during the monitoring visits in July 2008.

 

4.7               Construction materials such as planks, sand bags, metal rods were found to be placed over or near the lower trunks of some trees in Row C, L, O and R.  It was recommended that these materials should be kept in proper place to avoid damage to vegetation within works area. 

 

4.8               Concrete was found to be spilled over from the soil nailing works zones onto nearby areas.  It was recommended that the concrete should be removed from the soil surface.  The Contractor advised that the concrete will be removed and measures will be implemented to avoid any further spillage.

 

4.9               The leaves, branches and trunk of a tree (Machilus sp.) located in Row O was found to be covered with sand and mud probably generated from nearby soil nailing works. 

 

4.10            Two trees, Celtis sinensis and Machilus sp., located near the conveyor belt and above Row Q were found to be dead and in very poor condition respectively.  A dead tree (tree tag number T238) was collapsed within works area.  It was recommended that all dead trees found within the construction site should be recorded and reported to relevant departments without delay. 

 

4.11            Two main roots of a big tree (Acacia confusa of tree tag number T247) were cut due to the construction of soil nail number I6 (Figure 4.1).

 

4.12            The trunk of a tree (tree tag number T344) located next to a soil nailing area in Row O was covered with concrete.


5.     LANDSCAPE AND VISUAL

Monitoring Requirement

5.1               During the construction phase of the Project, landscape and visual monitoring should be carried out bi-weekly by a Registered Landscape Architect (RLA) to check if the design, implementation and maintenance of the landscape and visual mitigation measures are fully realized. A detailed report is annexed in Appendix J.

 

Summary of Inspection – 2 July 2008

 

Matters Arising from Previous Inspections

 

5.2               The Contractor had removed all metal pipes / steel bars previously stockpiled / stacked against the existing tree trunks at various locations on site, except for one location.  The Contractor was reminded to urgently remove it as soon as possible.

 

5.3               It was still noted that no tree protection with wooden slats was made for trees enclosed within the drilling platforms.  The Contractor was reminded to provide adequate tree protection works near the trees in order to prevent accidentally damaging the trees.

 

Protection of Existing Trees

 

5.4               Construction equipments were observed being placed against the tree trunks of existing trees at several locations on site.  The Contractor was requested to clear the equipment and not to place it against trees in future in order to prevent damage to the trees.

 

5.5               Also, soil bags were observed placed on slopes and rested at the base of the tree trunks.  The Contractor was requested to clear to soil bags away from the base of the tree as soon as possible.

 

5.6               Construction waste pile was observed on the slope.  The Contractor was requested to clear it away as soon as possible.  

 

Recommendations

 

5.7               The Contractor was recommended to provide more protection to existing trees which are enclosed within the drilling platforms in order to prevent the tree from being damaged.

 

5.8               The Contractor was recommended to keep all construction materials and equipments away from existing trees and not to place them against the trees in future.

 


Summary of Inspection – 15 July 2008

 

Matters Arising from Previous Inspections

 

5.9               The Contractor had removed all metal pipes previously stockpiled / stacked against the existing tree trunks on site.

 

5.10            The Contractor had cleared the construction equipments previously observed placed against the tree trunks of existing trees.

 

5.11            Clearance of soil bags previously observed being placed on slopes and rested at the base of the tree trunks was still outstanding.  The Contractor was reminded to clear it away as soon as possible.

 

5.12            Clearance of the construction waste pile previously observed on the slope was still outstanding.  The Contractor was reminded to clear it away as soon as possible.

 

Protection of Existing Trees

 

5.13            Scaffolding metal pipes were found with some being rested on and others being rested against existing trees.  The Contractor was requested to remove the pipes away from the trees as soon as possible.

 

Recommendations

 

5.14            The Contractor was recommended to provide more protection to existing trees which are enclosed within the drilling platforms in order to prevent the tree from being damaged.

 

5.15            The Contractor was recommended to keep all construction materials and equipments away from existing trees and not to place them against the trees in future.

 

5.16            The Contractor was reminded to clear the construction waste pile as found on the slope and keep the site in a tidy condition.

 


Summary of Inspection – 29 July 2008

 

Matters Arising from Previous Inspections

 

5.17            The Contractor had cleared away the construction waste pile previously observed on the slope.

 

5.18            The Contractor had cleared the scaffolding metal pipes away from existing trees.

 

5.19            Clearance of soil bags previously observed being placed on slopes and rested at the base of the tree trunks was still outstanding.  The Contractor was again reminded to clear it away as soon as possible.

 

Protection of Existing Trees

 

5.20            Existing tree T238 was found dead with rotten tree trunk at the base.  The Contractor was requested to remove the tree for safety as soon as possible.

 

5.21            It was observed that the Contractor had cut several large roots (up to 100mm diameter) of the existing large tree T247 while carried out the excavation for the soil nail head.  The Contractor was warned that the practice was unacceptable and large tree root shall not be cut without prior inspection and agreement with the Engineer.  The Contractor was requested to apply protective sealant to prevent the roots from rotting.

 

5.22            It was again observed that the Contractor had tied overhead plastic sheeting to existing tree trunks.  The Contractor was requested to remove the ties to prevent damage to the trees.

 

5.23            It was observed that the soil nail drilling had allowed the extracted materials fines being sprayed onto several tree trunks (i.e. T342).  The Contractor was requested to clean up the tree trunks and to provide protection to the tree trunks in future.

 

Recommendations

 

5.24            The Contractor was recommended to keep all soil bags away from existing trees and not to place them against the trees in future.

 

5.25            The Contractor was recommended to apply root protective sealant to the wounded roots.  The Contractor was recommended to seek the Engineer’s agreement for excavation works near existing tree roots in order to minimize damage to the tree root system.  If root pruning is required, prior approval from Engineer is required.

 

5.26            The Contractor was recommended to clean the material fines off the tree trunks and to provide tree protection in future when carried out drilling works.

 

 

 

Next Landscape and Visual Audit Schedule

 

5.27            The landscape and visual audits in the next reporting month was tentatively scheduled to 12 and 26 August 2008.

 

 


6.      ENVIRONMENTAL SITE INSPECTION AND AUDIT

 

Site Inspection

6.1               Site Inspections were carried out on a weekly basis to monitor the implementation of proper environmental pollution control and mitigation measures for the Project. In the reporting month, 5 site inspections were carried out on 2, 8, 15, 22 and 29 July 2008. The detail findings of the landscape and visual audits in the reporting month are presented separately in Section 5. The environmental site inspection summaries are attached in Appendix K. Particular observations are described below.

 

Air Quality

 

6.2               No adverse observation was identified in the reporting month.

 

 Noise

 

6.3               No adverse observation was identified in the reporting month.

 

Water Quality

 

6.4               Debris and leaves were observed inside the u-channel near Row R and Row S. The Contractor was reminded to clear the u-channel more frequently.

 

6.5               Minor muddy water was observed running down the u-channel near Row K and Row M. The Contractor was reminded to clear the exposed earth at all working platforms and properly maintain the desilting tank next to Row D.

 

Chemical and Waste Management

 

6.6               Oil drums and soil nail installation controller were found placed on ground without drip tray at Row Q, Row R and Row S. The Contractor was reminded to provide drip trays to the chemical containers and all plants on site.

 

Ecology

 

6.7               Sand bags and C&D materials were observed placed against the trees at Row C, Row D, Row E and Row R. The Contractor was reminded to keep the C&D materials away from the trees.

 

6.8               Construction materials placed near tree trunks and spillage of concrete near soil nailing areas were observed.  Some of the plants were not properly protected during soil nailing works and serious damages to root systems were recorded.  One recently dead tree was found within the works area.

 

Landscape and Visual

 

6.9               The Contractor was recommended to provide more protection to existing trees which are surrounded by drilling platforms and avoid stockpiling of any construction materials / equipments / sand bags against or near existing trees.

 

5.28            The Contractor was recommended to apply root protective sealant to the wounded roots.  The Contractor was recommended to seek the Engineer’s agreement for excavation works near existing tree roots in order to minimize damage to the tree root system.  If root pruning is required, prior approval from Engineer is required.

 

5.29            The Contractor was recommended to clean the material fines off the tree trunks and to provide tree protection in future when carried out drilling works.

 

Assessment of Environmental Monitoring Results

6.10            All monitoring results were audited against the Action / Limit levels and any exceedance would be validated and issued when necessary.

 

6.11            The monitoring results in the reporting period were comparable with the EIA predictions. Detailed discussions are given in Section 2 and 3.

 

Advice on the Solid and Liquid Waste Management Status

6.12            The Contractor is registered as a chemical waste producer for this Project. The Chemical Waste Storage Area located at the Contractor’s site office area was properly maintained in the reporting month.

 

6.13            No waste disposal was made in the reporting month. Most of the C&D waste generated was reused on site.

Environmental Licenses and Permits

6.14            The environmental licenses and permits for this Project and valid in the reporting month is summarized in Table 6.1.

 

Table 6.1      Summary of Environmental Licensing and Permit Status

Description

Permit No.

Valid Period

Remarks

From

To

Environmental Permit

EP-235/2005/B

23/11/07

--

-                                 Installation of about 700 nos. of soil nails and about 60 nos. of raking drains in the natural terrain;

-                                 Rock slope stabilisation works at upper portion of the natural terrain; and

-                                 Other associated works.

Registration as a Chemical Waste Producer

5213-141-C3250-02

13/12/06

--

Spent lubricating oil and mineral oil

Effluent Discharge License

EP880/W10/XX0261

07/11/06

31/12/11

--

Notification of Constriction Work under APCO (Construction Dust)

001012125

18/07/06

--

--

Implementation Status of Environmental Mitigation Measures

6.15            In response to the site audit findings, the Contractor carried out corrective actions.

 

6.16            A summary of the Implementation Schedule of Mitigation Measures (EMIS) is presented in Appendix C. Most of the necessary mitigation measures were implemented properly.

Summary of Exceedances of the Environmental Quality Performance Limit

6.17            All 1-hour TSP, 24-hour TSP and noise monitoring results complied with the Action / Limit levels.

 

6.18            No exceedance was recorded in the reporting month.

Summary of Complaints, Notification of Summons and Successful Prosecutions

6.19            The Environmental Complaint Handling Procedure is annexed in Figure 6.1.

 

6.20            No environmental complaint, notification of summons and successful prosecutions was received in the reporting month.


7.      FUTURE KEY ISSUES

Construction Programme for the Coming Months

7.1               The construction programme for the Project is provided in Appendix B.

 

7.2               The major construction work in August 2008 will be:

 

-          Soil Nail installaton at Portion A1, Portion A2 and Portion B1.

Key Issues for Coming Month

7.3               Key issues to be considered in the coming month included:

-          Properly store and label oils and chemicals on site;

-          Collection of construction waste should be carried out regularly;

-          Site runoff should be properly collected and treated prior to discharge;

-          Construction activities should avoid causing damage to the trees and to plants species of conservation interest;

-          Quieter powered mechanical equipment should be used.

 

7.4               The following mitigation measures are required:

 

Air Quality Impact

-          Regular watering should be used during soil nailing;

-          Dusty material stockpiled should be completely covered;

-          Dusty activities should be re-scheduled if high-wind conditions encountered;

-          Open burning should be strictly prohibited;

-          All dusty vehicle loads transporting to, from and between site locations should be covered with tarpaulin;

-          Vehicle wheel and body washing facilities should be used at all exit points of the site;

-          Wind shield, dust extraction units or water spraying should be used at the loading points.

 

Construction Noise Impact

-          Quieter powered mechanical equipment should be used;

-          Insulating fabric should be used for drill rigs during drilling process;

-          Noise generating construction works should be carried out during daytime only;

-          Noise barriers or other measures should be used to minimize disturbance to the bat roost;

-          Plant on site should be properly maintained and serviced regularly;

-          Mobile plants should be sited as far from NSRs as possible;

-          Machines and plant in intermittent use should be throttled down;

-          Strong noise emitting plants, wherever possible, should be oriented so that noise is directed away from the nearby NSRs;

-          Material stockpiles, wherever possible, should be effectively utilized to screen noise from construction activities;

-          Movable noise barrier with surface mass in excess of 7kg/m2 should be used for PME wherever possible;

-          Noise insulating fabric should be adopted for drill rig operating in Works Area E.

 

Water Quality Impact

-          Prevent runoff water from entering the nearby water-bodies;

-          Silt traps and oil / grease separators should be regularly cleaned and maintained;

-          Outlet pipe extending above the slope surface should be installed;

-          Air should be used as the flushing medium of the drilling equipment;

-          Earth bunds or sand bag barriers should be provided on-site to direct storm water to silt removal facilities;

-          Exposed slope / soil surface and opened stockpile of more than 50m3 should be covered with tarpaulin;

-          Oils and fuels should be used and stored in designated area.

 

Chemical and Waste Management

-          Debris and rubbish on-site should be collected, handled and disposed of properly;

-          Waste skips should be provided to collect general refuse and construction wastes;

-          Soil contamination with fuel leaked from construction plants should be removed off-site;

-          Sufficient waste disposal points with regular collection should be provided;

-          Appropriate measures should be provided to minimize windblown litter and dust during transportation of waste;

-          Different containers should be used to segregate and store different types of waste;

-          Encourage collection of aluminum cans, PET bottles and paper by providing separate bins;

-          Unused chemicals should be recycles wherever possible;

-          Proper storage and site practices should be adopted to minimize the potential for damage and contamination of construction materials;

-          Oils and fuels should be stored in designated area;

-          Plan and stock construction materials carefully to minimize waste generation.

 

Ecological Impact

-          Soil nail installation should avoid / minimize damage of root system to the existing plants;

-          Fences should be erected along the boundary of the works area

-          Disturbance to the natural woodland and shrubland habitats should be minimized by preventing tipping, vehicle movements and encroachment of personnel onto the adjacent area;

-          Permanent casing should be provided to the drillhole of soil nail;

-          Placement of equipment or stockpile should be located in designated areas to minimize disturbance to natural or moderate-high ecological value habitats;

-          Construction activities should be restricted to works areas;

-          Disturbance to existing vegetation should be minimized wherever possible.

 

Landscape and Visual Impact

-          Designation of “no-intrusion zones” and record any trespass and damage to existing vegetation;

-          Soil nails on site should avoid tree trunks and tree roots;

-          Dust and erosion control should be provided for exposed soil;

-          For tree planting operations, method statement should be checked against specification requirements;

-          All retained trees within the working boundary should be checked regularly;

-          Control over appearance of hoarding, construction plants / machines;

-          Security floodlights should be carefully selected to avoid light pollution.

Monitoring Schedule for the Coming Months

7.5               The tentative schedule for environmental monitoring in August 2008 is provided in Appendix L.


8.      CONCLUSIONS AND RECOMMENDATIONS

Conclusions

8.1               The construction phase of the project commenced in April 2008.

 

8.2               1-hour TSP and 24-hour TSP monitoring was carried out in the reporting month. All monitoring results complied with the action / limit level. No exceedance was recorded.

 

8.3               All impact daytime noise monitoring results complied with the limit level in the reporting month.

 

8.4               Environmental site inspections were carried out 5 times in July 2008. Recommendations on remedial actions were given to the Contractor for the deficiencies identified during the site audit.

 

8.5               Three landscape and visual audits were carried out in the reporting month. The Contractor was recommended to provide more adequate protection to existing trees in the work areas and keep all C&D materials / equipments / sand bags away from the trees. The Contractor was also recommended to apply root protective sealant to the wounded root and the Engineer’s agreement should be sought for excavation works near existing tree roots in order to minimize damage to the tree root system.  If root pruning is required, prior approval from Engineer is required.

 

8.6               Construction materials placed near tree trunks and spillage of concrete near soil nailing areas were observed.  Some of the plants were not properly protected during soil nailing works and serious damages to root systems were recorded.  One recently dead tree was found within the works area.

 

8.7               No environmental complaint, notification of summons and prosecution was received in the reporting month.

Recommendations

8.8               According to the environmental site inspections performed in the reporting month, the following recommendations were provided:

 

Air Quality Impact

-          Soil nail workstations on site should be fully enclosed; and

-          Exposed earth surface at all working platforms should be covered with tarpaulin sheets.

 

Construction Noise Impact

-          Nil

 

Water Quality Impact

-          U-channels should be kept clear of mud, debris, construction waste and leaves;

-          Soil and earth at all working platforms should be cleared; and

-          The desilting tank near Row D should be maintained properly.

 

Chemical and Waste Management

-          Drip trays should be provided to all plants and chemical containers on site;

-          Oils and fuels should be stored in designated area;

-          Sand bags and C&D materials should be kept away from the trees;

-          C&D waste, debris and general refuse on-site should be collected, handled and disposed of properly; and

-          Waste skips should be provided to collect general refuse and construction wastes.

 

Ecological Impact

-          Hessian sacking should be wrapped around the trunk of vegetation to prevent damage during the transportation of construction materials.

 

 

Landscape and Visual Impact

-          Soil nails on site should avoid tree trunks and tree roots;

-          More adequate protection should be provided to existing trees in the work areas and during drilling works; and

-          Stockpiling of any construction materials / equipments / sand bags against or near existing tree should be avoided.