Silt Curtain Efficiency Test MS

Construction Activities	Scenario	Type of Silt Curtain	Loss Reduction Factor	Remarks ^(b)	Justification
Dredging Works	A	Cage-type for grab dredger (1)	80%	ü	Cage type silt curtain will be deployed throughout the dredging works.
	B	Single-layer floating type silt curtain (2)	75%	û	Single layer silt curtain will not be deployed individually for dredging works.
	C	Second layer of floating silt curtain (3)	50%	û	Not used
	D	Combined silt curtains (1 + 2)	95%	ü	Dredging for seawall construction at the remaining section of Portion N-A during Phase II Reclamation will be commenced in the fourth quarter of year 2016, in which dredging will be undertaken inside the cage type silt curtain and a single layer silt curtain will be deployed at Portion N-A parallel to the works boundary.
	E	Combined silt curtains (1 + 2 + 3)	97%	û	Not used.
	F	Combined (2 + 3)	87%	û	Not used.
Filling Activities	G	Single-layer floating type silt curtain (4)	45%	ü û	For filling works in Phase II Reclamation, two options for construction method are being considered ^(c): Option 1. Filling works will commence behind the completed seawall with a 100m gap for marine access at Portion N-A. A single-layer floating type silt curtain will be deployed at Portion N-A parallel to the works boundary. Option 2. Filling works will commence after the completion of the fully enclosed seawall with no gaps for marine access at Portion N-A, hence Scenario G will not be applicable for this option. The silt curtain will remain in place in accordance with Stage 5 of Figure 1.1 until the completion of marine works for Phase-II Reclamation.
	H	Second layer of silt curtain (5)	30%	û	Not used.
	I	Combined silt curtains (4 + 5)	61%	û	Not used.
*Notes
(a) Sequence B in the approved EIA report is not included which is related to the construction at Southern Landfall, and thus is out of the scopes of this Contract. (b) ü = relevant to this Contract and Pilot Tests are proposed in this Method Statement; û = not relevant or not used in this Contract, thus no Pilot Tests is proposed. (c) Silt curtain efficiency test for Scenario G would only be conducted if the Contractor proceeded to option 1 during Phase II Reclamation.

The latest progress of dredging/ filling works is summarized as follows:

Phase I Reclamation (Stage 1 to 4 in Figure 1.1)

· Dredging for seawall construction at Portions N-A, N-B and N-C has been completed in mid-July 2014;

· Dredging in the middle of Portion N-C has been completed in late-August 2014; and

· The first phase reclamation filling was commenced from Portion N-A in March 2014 and has been completed in the fourth quarter of year 2014.

Phase II Reclamation (Stage 5 to 6 in Figure 1.1)

· Dredging for seawall construction at the remaining section of Portion N-A will commence in the fourth quarter of year 2016; and

· Filling behind seawall at the remaining section of Portion N-A will commence in the fourth quarter of year 2016.

Phase II Reclamation will commence in the fourth quarter of 2016 and will be completed in early 2017 tentatively. During the preparation of this Method Statement, dredging and filling works for Phase I Reclamation was completed. Tentative construction programme for Phase II reclamation is provided in Annex B for reference.

In this Method Statement, the Pilot Tests are proposed for the pertinent silt curtain scenarios considering in the EIA and the latest design under this Contract. As informed by the Contractor, the construction method for Phase II Reclamation is detailed below:

Construction method for Phase II Reclamation

Dredging Works – Scenarios A & D

Dredging for seawall construction at Portion N-A will be undertaken inside the cage type silt curtain and a single layer silt curtain will be deployed at Portion N-A parallel to the works boundary. Under this construction method, silt curtain arrangement for Scenarios A and D will take place (see Figure 1.2).

Filling Works – Scenario G

For filling works, two options for construction method are being considered:

Option 1 - Filling works will commence behind the completed seawall with a 100m gap for marine access at Portion N-A. A single-layer floating type silt curtain will be deployed at Portion N-A parallel to the works boundary. Under this construction method, silt curtain arrangement for Scenarios G will take place (see Figure 1.3). The actual Pilot Test scenario to be conducted will be based on the situation of abovementioned construction method during Phase II Reclamation.

Option 2 - Filling works will commence after the completion of the fully enclosed seawall with no gaps for marine access at Portion N-A, hence Scenario G will not be applicable for this option. The silt curtain will remain in place in accordance with stage 5 of Figure 1.1 until the completion of marine works for Phase-II Reclamation. The proposed construction method for Option 2 is illustrated in Figure 1.4.

1.2.2 Monitoring Locations

Phase II Reclamation - Dredging Activities under Scenarios A and D

For scenarios A and D, given the dredging area in Portion N-A is confined in nature and the reclaimed Northern Landfall and the River Trade Terminal will act as a physical barrier to restrict tidal flushing, significant tidal influence on the proposed Impact monitoring stations is not envisaged. Impact/Outer zone stations downstream of the dredging site are proposed for ebb tide only due to the locations of the dredging site and the silt curtain as shown in Figure 1.2. The monitoring locations are determined based upon the locations of the dredging activities under the Contract and the proposed silt curtain layout. In addition, upstream Control Station for impact water quality monitoring will also be monitored to facilitate comparison of the ambient water quality conditions in the surrounding environment. The proposed locations of the monitoring stations for the Pilot Tests of scenarios A and D are illustrated in Figure 1.2 and detailed in Table 1.2.

Table 1.2 Monitoring Stations for Pilot Tests of Silt Curtain Efficiency – Dredging under Scenarios A and D. Indicative locations are presented.

Monitoring Stations	Description	Type of Silt Curtain	Easting	Northing
DI	Impact zone – area enclosed by the cage-type silt curtain	/	812710	825093
DO1	Outer zone – downstream location at approximately 100 m from the cage-type silt curtain	Cage-type (Scenario A)	812775	825098
DO2	Outer zone – downstream location at approximately 100 m from the single layer floating type silt curtain	Combined silt curtains (1+2) (Scenario D)	812884	825101
CS4 (ebb)	Upstream control station during mid-ebb tide	/	810025	824004
*Note: The status and locations of the actual monitoring locations may change after issue of this method statement. If this happens, the ET will agree with the SOR, in consultation with the IEC/ENPO, to propose the alternative and updated monitoring location.

The Impact zone station DI is defined as the active dredging area enclosed by the cage-type silt curtain, whilst the Outer zone stations DO1 and DO2 are defined as at a distance approximately 100 m away from the cage-type silt curtain and 100 m away from the combined silt curtains (1+2), respectively. Based on the predictions in the approved EIA report ([3]), this is expected to represent the extent of the zone of influence resulting from marine construction activities under this Contract. The actual locations of these stations will be determined on site based on the location of the dredging activities. Since DI is located at the immediate vicinity of the active dredging area within the cage-type silt curtain, due to safety consideration and progress of dredging works, its location may vary. The actual location of monitoring stations will be updated in the monitoring report of the Pilot Tests for any discrepancy from the proposed.

The loss reduction factor between impact and outer zones of deployed silt curtain will be evaluated for the respective scenario (see Section 1.2.9). Water quality monitoring at the Control Station will be evaluated against Action and Limit Levels to identify any exceedances found during the marine works under this Contract (see Section 1.2.9).

Phase II Reclamation - Filling Activities under – Scenario G

Filling Works – Scenario G

For scenario G, two sets of monitoring stations will be arranged, comprising both Impact zone and Outer zone of the silt curtain. Given the filling area is confined in nature and the reclaimed Northern Landfall and the River Trade Terminal will act as a physical barrier to restrict tidal flushing, the tidal influence on the proposed Impact monitoring stations is not envisaged. The Impact/Outer zone stations downstream of the filling site are proposed for ebb tide only due to the locations of the filling site and the silt curtain as shown in Figure 1.3). In addition, Control Station for impact water quality monitoring will also be monitored to facilitate the comparison of ambient water quality conditions in the surrounding environment. The indicative locations of the monitoring stations for the Pilot Tests for filling activities are illustrated in Figure 1.3 and detailed in Table 1.3.

Table 1.3 Monitoring Stations for Pilot Tests of Silt Curtain Efficiency – Filling under Scenario G. Indicative locations are presented.

Monitoring Stations	Description	Type of Silt Curtain / Barrier	Easting*	Northing*
FI	Impact zone – the active filling area	/	812697	825069
FO	Outer zone - approximately 100 m downstream of the single-layer silt curtain	Single-layer floating type	812781	825122
CS4 (ebb)	Upstream control station during mid-ebb tide	/	810025	824004
*Note: The status and locations of the actual monitoring location may change after issue of this method statement. If this happens, the ET will agree with the SOR, in consultation with the IEC/ENPO, to propose the alternative and updated monitoring location.

The Impact station FI is defined as the active filling area enclosed by the single-layer silt curtain, whilst the Outer zone station FO is defined as at a distance approximately 100 m downstream of the single-layer silt curtain. Based on the predictions in the approved EIA report, this is expected to represent the extent of the zone of influence resulting from marine construction activities under this Contract. The actual locations of these stations will be determined on site based on the location of the filling activities. Since the FI is located in the close proximity of the active filling area, due to safety consideration and progress of filling activities, its location may vary.

The actual location of monitoring stations will be updated in the monitoring results of the Pilot Tests for any discrepancy from the proposed. The loss reduction factor between impact and outer zone of deployed silt curtain will be evaluated for the respective scenario (see Section 1.2.9). Current measurements will be taken at Outer zone monitoring station during the course of water quality monitoring for the ebb tide. Water quality monitoring at the Control Station will be evaluated against Action and Limit Levels to identify any exceedances found during the marine works under this Contract (see Section 1.2.9).

Given the Pilot Tests are aimed to evaluate primarily on the efficiency of silt curtains where the majority of marine works to be undertaken, no monitoring will be conducted for scenarios of silt curtain and seawall combination. In addition, the same geotextile material of silt curtain is deployed within the site area of Contract No. HY/2012/08, thus the findings from the Pilot Tests within the leading seawall would be applicable for the same silt curtain arrangement elsewhere (e.g. dredging and filling at Portion N-A in year 2016 during Phase II Reclamation) under this Contract.

1.2.3 Monitoring Parameters

The parameters that have been selected for measurement in situ and in the laboratory are those that were determined in the approved EIA report with higher potential to be affected by the dredging and filling works (i.e. suspended solids and turbidity) and other general water quality parameters (ie dissolved oxygen, salinity and temperature).

The parameter to be measured in the laboratory for silt curtain efficiency evaluation is:

· Suspended solids (SS) (mg L^-1)

In addition to the water quality parameters, other relevant data will also be measured and recorded in Water Quality Monitoring Logs, including the location of the sampling stations, water depth, time, weather conditions, sea conditions, tidal stage, current direction and velocity, special phenomena and work activities undertaken around the monitoring and works area that may influence the monitoring results.

1.2.4 Monitoring Equipment

For water quality monitoring, the following equipment will be used:

· Dissolved Oxygen and Temperature Measuring Equipment - The instrument will be a portable, weatherproof dissolved oxygen measuring instrument complete with cable, sensor, comprehensive operation manuals, and will be operable from a DC power source. It will be capable of measuring: dissolved oxygen levels in the range of 0 - 20 mg L^-1 and 0 - 200% saturation; and a temperature of 0 - 45 degrees Celsius. It shall 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 cables shall be available for replacement where necessary (e.g. YSI Pro 2030 or an approved similar instrument).

· Turbidity Measurement Equipment - The instrument will be a portable, weatherproof turbidity-measuring. The equipment will be operated from a DC power source, it will have a photoelectric sensor capable of measuring turbidity between 0 - 1000 NTU (for example Hach 2100Q or an approved similar instrument).

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

· Water Depth Gauge – A portable, battery-operated echo sounder (e.g. Seafarer 700 or a similar approved instrument) will be used for the determination of water depth at each designated monitoring station. This unit will either be hand-held or affixed to the bottom of the work boat if the same vessel is to be used throughout the monitoring period.

· Current Velocity and Direction – A current meter capable of measuring the velocity and direction of flow in the range of 0 – 6 m/s (± 0.01 m/s) and 0° to 360° (± 2°), respectively, will be used (e.g. Falmouth Scientific, Inc. 2-Dimensional Acoustic Current Meter or a similar approved instrument). The specification of the proposed current meter is provided in Annex C.

· Positioning Device – A Differential Global Positioning System (DGPS) shall be used during monitoring to allow accurate recording of the position of the monitoring vessel before taking measurements. The DGPS should be suitably calibrated at appropriate checkpoint to verify that the monitoring station is at the correct position before the water quality monitoring commence.

· Water Sampling Equipment - A water sampler, consisting of a PVC or glass cylinder of not less than two litres, which can be effectively sealed with cups at both ends, will be used (e.g. Kahlsico Water Sampler 13SWB203 or an approved similar instrument). The water sampler will 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.

The specification of geotextile employed as silt curtain under this Contract is provided in Annex C.

Prior to the Pilot Tests, the valid calibration certificates of the monitoring equipment to be used in situ will be provided to the SOR, the Contractor(s), and IEC/ENPO for agreement. All valid calibration certificates will be attached to the monitoring report. Examples of calibration certificates are shown in Annex D.

1.2.5 Sampling / Testing Protocols

All in situ monitoring instruments will be checked, calibrated and certified by a laboratory accredited under HOKLAS([4]) or any other international accreditation scheme before use. Responses of sensors and electrodes will be checked with certified standard solutions before each use.

On-site calibration of field equipment shall follow the “Guide to On-Site Test Methods for the Analysis of Waters”, BS 1427: 2009. Sufficient stocks of spare parts shall be maintained for replacements when necessary. Backup monitoring equipment shall also be made available so that monitoring can proceed uninterrupted even when equipment is under maintenance, calibration etc.

1.2.6 Laboratory Measurement and Analysis

All laboratory work shall be carried out in a HOKLAS accredited laboratory ([5]). Water samples of about 1,000 mL shall be collected at the monitoring and control stations for carrying out the laboratory analyses. Water samples for SS measurements will be collected in high density polythene bottles, packed in ice (cooled to 4° C without being frozen), and delivered to a HOKLAS laboratory as soon as possible after collection.

The determination work shall start within the next working day after collection of the water samples. The SS laboratory measurements shall be provided to the ET within 7 working days upon the receipt of the samples. The analyses shall follow the standard methods as described in APHA Standard Methods for the Examination of Water and Wastewater, 19th Edition, unless otherwise specified (APHA 2540D for SS) with a detection limit of 0.5 mg L^-1.

The submitted information should include pre-treatment procedures, instrument use, Quality Assurance/Quality Control (QA/QC) details (such as blank, spike recovery, number of duplicate samples per-batch etc), detection limits and accuracy. The QA/QC details shall be in accordance with requirements of HOKLAS or another internationally accredited scheme.

1.2.7 Monitoring Frequency & Arrangements

Dredging Activities – Scenarios A and D

Monitoring will be conducted at all designated stations at mid-ebb tide in the course of dredging activities. The tentative monitoring schedule is presented in Table 1.4.

Table 1.4 Tentative Monitoring Schedule of Background Monitoring and Pilot Tests for Dredging

Scenarios	Tide	Monitoring	Monitoring stations	Quantities	Time	Frequency
Scenarios A and D	Mid-ebb	Background Monitoring	DI, DO1, DO2 & CS4	Σ n = 2 replicates x 3 depths x 4 stations x 1 monitoring event = 24	Prior to Pilot Test when no dredging works is carried out under this Contract	One set of measurement at each stations when no dredging works is undertaken under this Contract at ebb tide
		Pilot Test	DI, DO1 & DO2	Σ n = 2 replicates x 3 depths x 3 stations x 4 monitoring events = 72	Within ±2 hours from the predicted mid-ebb tide during the period of dredging works	Every 1-hour (time= hr-1, hr-2, hr-3, hr-4) during the 4-hour of Pilot Tests at ebb tide
		Impact Monitoring	CS4*	Σ n = 2 replicates x 3 depths x 1 station x 1 monitoring event = 6	Within ±2 hours from the predicted mid-ebb tide during the period of dredging works	One set of measurement at the Control station within ±2 hours from the predicted mid-ebb tide during the period of dredging works
*Note: Monitoring events for Control Station CS4 will only be carried out once in the same manner as the impact marine water quality monitoring.

Background Monitoring

Background monitoring will be conducted at the designated monitoring stations prior to any dredging activities take place of the day under this Contract. The background monitoring is to investigate whether the change in the ambient environmental condition irrespective to any dredging activities take place under this Contract.

Pilot Tests for Dredging Scenarios A & D

Upon dredging commenced, water samples for SS laboratory analysis will be collected with the in situ parameters measurements starting from Outer zone (e.g. DO1, DO2) and eventually at Impact zone Station (e.g. DI). Per each monitoring event, the in situ measurements and SS sampling will be conducted every one hour for 4-hour in the predicted mid-ebb tide. Monitoring at the respective Control Station (i.e. CS4) will be undertaken in the same manner as the impact marine water quality EM&A for this Contract as to compare the water quality from the dredging site with the ambient water quality.

For a better understanding of the relationships between loss reduction factor and the dredging activities, information such as dredging rate and dredged volume during the pilot test, actual location of dredging works, will be recorded and reported together with the monitoring results.

Filling Activities – Scenario G

Monitoring will be conducted at all designated stations at mid-ebb tide in the course of reclamation filling. The tentative monitoring schedule is presented in Table 1.5.

Table 1.5 Tentative Monitoring Schedule of Background Monitoring and Pilot Tests for Filling

Scenario	Tide	Monitoring	Monitoring stations	Quantities	Time	Frequency
Scenario G	Mid-ebb	Background Monitoring	FI, FO & CS4	Σ n = 2 replicates x 3 depths x 3 stations x 1 monitoring event = 18	Prior to Pilot Test when no filling works is carried out under this Contract	One set of measurement at each stations when no filling works is undertaken under this Contract at ebb tide
		Pilot Test	FI & FO	Σ n = 2 replicates x 3 depths x 2 stations x 4 monitoring events = 48	Within ±2 hours from the predicted mid-ebb tide during the period of filling works	Every 1-hour (time= hr-1, hr-2, hr-3, hr-4) during the 4-hour of Pilot Tests at ebb tide
		Impact Monitoring	CS4*	Σ n = 2 replicates x 3 depths x 1 station x 1 monitoring event = 6	Within ±2 hours from the predicted mid-ebb tide during the period of filling works	One set of measurement at the Control station within ±2 hours from the predicted mid-ebb tide during the period of filling works

*Note: Monitoring events for Control Station CS4 will only be carried out once in the same manner as the impact marine water quality monitoring.

Background Monitoring

Background monitoring will be conducted at the designated monitoring stations prior to any filling activities take place of the day under this Contract. The background monitoring is to investigate whether the change in the ambient environmental condition irrespective to any filling activities take place under this Contract.

Pilot Tests for Filling Scenario G

Upon filling commenced, water samples for SS laboratory analysis will be collected with the in situ parameters measurements starting from Outer zone (eg. FO) and eventually at Impact zone Station (eg. FI). Per each monitoring event, the in situ measurements and SS sampling will be conducted every one hour for 4-hour in the predicted mid-ebb tide. Monitoring at the respective Control Station (i.e. CS4) will be undertaken in the same manner as the impact marine water quality EM&A for this Contract as to compare the water quality from the filling site with the ambient water quality.

For a better understanding of the relationships between loss reduction factor and the filling activities, information such as filling rate during the pilot test, number of dump barge used, types of filling material used, actual location of filling works, distance between filling activities and FI station, will be recorded and reported together with the monitoring results.

1.2.8 Sampling Depths & Replication

Each station will be sampled and measurements will be taken at three depth, 1 m below sea surface, mid-depth and 1 m above the seabed. Duplicate (2) readings of the in situ measurements and duplicate (2) SS samples will be made at each water depth at each station. For stations that are less than 3 m in depth, only the mid depth sample will be taken. For stations that are less than 6 m in depth, the mid-depth station will be omitted.

As the QA/QC procedures for the in-situ measurement of DO and Turbidity, where the difference in value between the first and subsequent measurements at a certain depth is more than 25% of the value of the first measurement, the measurements should be discarded and further measurements should be taken to confirm the values.

Safety is the highest priority during sampling works and it will cease should conditions warrant ensuring the safety of the staff. The risk assessment of health and safety for silt curtain installation and related works is provided in Annex E.

1.2.9 Loss Reduction Factor and Water Quality Compliance

The efficiency of the silt curtains will be evaluated against the relevant loss reduction factor for suspended solids (Table 1.6 & 1.7) with reference to the approved EIA of TM-CLKL (Table D6-1 in Appendix D6a).

For Scenario A,

Loss Reduction Factor = 100* [(SS (in) - SS (out)) / SS (in)]

where
SS(in) = DI
SS(out) = DO1.

For Scenario D,

Loss Reduction Factor = 100* [(SS (in) - SS (out)) / SS (in)]

where
SS(in) = DI
SS(out) = DO2.

For Scenario G,

Loss Reduction Factor = 100* [(SS (in) - SS (out)) / SS (in)]

where
SS(in) = FI
SS(out) = FO.

Table 1.6 Loss Reduction Factor of Silt-removal Efficiency for Dredging

Parameter	Scenario	Loss Reduction Factor	Loss Reduction Criteria
Suspended Solids (SS) in mg/L (Depth-averaged ^(a))	A	100* [ (SS (in) - SS (out)) / SS (in)] ^(b)	Loss reduction factor ≥ 80%
	D	100* [ (SS (in) - SS (out)) / SS (in)] ^(b)	Loss reduction factor ≥ 95%
Notes:
a. “Depth-averaged” is calculated by taking the arithmetic means of reading of all three depths.
b. (out): represents mean measurement of SS at Outer zone (e.g. Monitoring station DO1/DO2) of dredging works during the same tidal cycle. (in): represents mean measurement of SS at Impact zone (e.g. Monitoring station DI) of dredging works during the same tidal cycle.

Table 1.7 Loss Reduction Factor of Silt-removal Efficiency for Filling

Parameter	Scenario	Loss Reduction Factor ^(b)	Loss Reduction Criteria
Suspended Solids (SS) in mg/L (Depth-averaged ^(a))	G	100* [ (SS (in) - SS (out)) / SS (in)]	Loss reduction factor ≥ 45%

Notes:
a. “Depth-averaged” is calculated by taking the arithmetic means of reading of all three depths.
b. (out): represents mean measurement of SS at Outer zone (e.g. Monitoring station FO) of filling activities during the same tidal cycle. (in): represents mean measurement of SS at Impact zone (e.g. Monitoring station FI) of filling activities during the same tidal cycle.

Since the proposed Control Station (i.e. CS4) is adopted from the Contract Specific EM&A Manual, the Action and Limit Levels for the Water Quality Monitoring will also be adopted from the manual (please refer to Section 5.12 of the manual) ([6]). Water quality monitoring at the Control Station will be evaluated against Action and Limit Levels (Table 1.8).

Table 1.8 Action and Limit Levels for Water Quality Monitoring

Parameter	Action Level#	Limit Level#
DO in mg/L ^{(a), (e)}	Surface and Middle	Surface and Middle
	5.0 mg/L	4.2 mg/L
	Bottom	Bottom
	4.7 mg/L	3.6 mg/L
Turbidity in NTU (Depth-averaged ^{(b), (c)})	120% of upstream control station at the same tide of the same day and 95%-ile of baseline data, i.e., 27.5 NTU	130% of upstream control station at the same tide of the same day and 99%-ile of baseline data, i.e., 47.0 NTU
SS in mg/L (Depth-averaged ^{(b), (c)})	120% of upstream control station at the same tide of the same day and 95%-ile of baseline data, i.e., 23.5 mg/L	130% of upstream control station at the same tide of the same day and 10mg/L for WSD Seawater Intakes at Tuen Mun and 99%-ile of baseline data, i.e., 34.4 mg/L
Notes:
# Baseline data: data from HKZMB Baseline Water Quality Monitoring between 6 and 31 October 2011.
(a) For DO, non-compliance of the water quality limits occurs when monitoring result is lower than the limits.
(b) “Depth-averaged” is calculated by taking the arithmetic means of reading of all three depths.
(c) For turbidity and SS, exceedance of the water quality occurs when monitoring result is higher than the Action/Limit levels.
(d) All figures given in the table are used for reference only, and EPD may amend the figures whenever it is considered as necessary.
(e) The 1%-ile of baseline data for surface and middle DO is 4.2 mg/L, whilst for bottom DO is 3.6 mg/L.

1.3 Reporting

In respect to the construction phase EM&A marine works, the ET will prepare and submit the monitoring results of the Pilot Tests for Silt Curtain Efficiency within 30 working days following the completion of the monitoring. Copies of the monitoring results of the Pilot Tests for Silt Curtain Efficiency will be submitted to the following: the Contractor(s), the SOR, the IEC/ENPO and the EPD as appropriate. The ET will liaise with the relevant parties on the exact number of copies required.

As stated in the Contract Specific EM&A Manual ([7]), regardless of the measured efficiency of the silt curtain system, the event and action plan provided in the Contract Specific EM&A Manual will only be based on the monitoring results at the designated monitoring stations.

1.4 Event & Action Plan

Should exceedance of the Action/Limit Levels are reported at the Control Station, the Event and Action Plan of Water Quality stipulated in Table 5.3, Section 5.12 of the Contract Specific EM&A Manual shall be followed ([8]).

([1]) Accessible at http://www.hzmbenpo.com/emna_report/tmclkl_hy201208/manual/html/toc.htm.

([2]) The notification of change in construction sequence was submitted to ENPO in September 2014 and was subsequently approved by EPD on 7 October 2014. The approved notification of change in construction sequence is presented in Annex A.

([3]) Based on Section 6.9 of the approved EIA predictions by Delft3D hydrodynamic models, the sediment plumes are predicted to be confined to within about 500 m of the project site.

([4]) The laboratory will be contracted before commencement of the monitoring.

([5]) The laboratory will be contracted before commencement of the monitoring.

([6]) Accessible at http://www.hzmbenpo.com/emna_report/tmclkl_hy201208/manual/html/toc.htm.

([7]) Accessible at http://www.hzmbenpo.com/emna_report/tmclkl_hy201208/manual/html/toc.htm.

([8]) The event and action plan shall only be based on the monitoring results at the designated Control monitoring stations, regardless of the outcome of the measured efficiency of the silt system being tested, as stated in the EM&A Manual.

1 Pilot Tests for Silt Curtain Efficiency

1.1 Introduction

1.2 Monitoring Requirement

1.2.1 Construction design and silt curtain arrangements

Construction method for Phase II Reclamation

1.2.2 Monitoring Locations

Phase II Reclamation - Dredging Activities under Scenarios A and D

Phase II Reclamation - Filling Activities under – Scenario G

1.2.3 Monitoring Parameters

1.2.4 Monitoring Equipment

1.2.7 Monitoring Frequency & Arrangements

Dredging Activities – Scenarios A and D

Background Monitoring

Pilot Tests for Dredging Scenarios A & D

*Note: Monitoring events for Control Station CS4 will only be carried out once in the same manner as the impact marine water quality monitoring.

Background Monitoring

Pilot Tests for Filling Scenario G

1.2.8 Sampling Depths & Replication

1.2.9 Loss Reduction Factor and Water Quality Compliance

1.3 Reporting

1.4 Event & Action Plan