Contents
1.1 Purpose of the
Manual
1.2 Review of
EM&A Manual
1.3 Project
Description
1.4 Background to the
EM&A Programme
1.5 The Scope of the
EM&A Programme
1.6 Objectives of the
EM&A Programme
1.7 Organisation and
Structure of the EM&A
1.8 Structure of the
EM&A Manual
2.1 Introduction
2.2 EM&A
3.1 Introduction
3.2 Monitoring
Activities
3.3 Monitoring for
Dredging Activities of CMP V
3.4 Monitoring for
Backfilling Activities
3.5 Monitoring for
Capping Activities
3.6 Sampling
Procedure for Water Quality monitoring
3.7 QA/QC
4.1 Introduction
4.2 Objective
4.3 Hypotheses
4.4 Sampling Design
4.5 Statistical
Treatment of Data
4.6 Use of Data
4.7 Sampling
Procedure and Equipment
4.8 QA/QC
4.9 Data Quality
Objectives
5.1 Introduction
5.2 Objective
5.3 Hypothesis
5.4 Sampling Design
5.5 Statistical
Treatment of Data
5.6 Use of Data
5.7 Data Collection
Parameters
5.8 Sampling
Procedure and Equipment
5.9 QA/QC
6.1 Introduction
6.2 Objective
6.3 Hypothesis
6.4 Sampling Design
6.5 Statistical
Treatment of Data
6.6 Use of Data
6.7 Data Collection
Parameters
6.8 Sampling
Procedure and Equipment
7 Human
Health and Ecological Risk Assessment
7.1 Introduction
7.2 Objective
7.3 Hypothesis
7.4 Sampling Design
7.5 Use of Data
8.1 Introduction
8.2 Objective
8.3 Hypothesis
8.4 Sampling Design
8.5 Statistical
Treatment of Data
8.6 Use of Data
8.7 Laboratory
Procedures
8.8 Benthic
Macro-Infauna and Taxonomic Identification
9.1 Introduction
9.2 Sampling Design
10 Reporting
10.1 General
10.2 Reports
ANNEXES
Annex A Implementation Schedule for CMP V
Annex B Complaints Proforma
Annex C Sampling Programme
1
Introduction
1.1
Purpose of the
Manual
This Environmental Monitoring and Audit (EM&A) Manual
(the Manual) has been prepared by ERM-Hong
Kong, Limited (ERM) on behalf of the Civil Engineering and Development
Department (CEDD) of the Hong Kong Special Administrative Region (HKSAR)
Government.
The purpose of the Manual is to provide information,
guidance and instruction to personnel charged with environmental duties and
those responsible for undertaking EM&A work during the operation of
Contaminated Mud Pit IV and V (CMP IV and CMP V) at East of Sha
Chau. It
provides systematic procedures for monitoring and auditing of potential
environmental impacts that may arise from the works.
EM&A works relating to CMP V have been prepared
in accordance with the Environmental Permit (EP-312/2008/A) (EP) for Disposal
of Contaminated Sediment Dredging, Management and Capping of Sediment
Disposal Facility at Sha Chau
(hereafter referred as the Project) and the Technical Memorandum of the
Environmental Impact Assessment Process (EIAO TM).
1.2
Review of
EM&A Manual
The EM&A Manual is an evolving document that
should be updated to maintain its relevance as the Project progresses. The primary focus for reviews of the EM&A
Manual will be to ensure the impacts predicted and the recommended mitigation
measures remain consistent and appropriate to the manner in which the works are
to be carried out.
This second review of the EM&A Manual has been
made to integrate the EM&A requirements of both the existing (CMP IV) and
new (CMP V) disposal facilities at Sha Chau in order to facilitate the subsequent implementation
of the respective EM&A works. This
includes suitable provisions for the monitoring requirements of CMP IV after
the pits are filled and capped. This
EM&A Manual incorporates the requirements for the second review. Further reviews and subsequent updates will
be undertaken whenever necessary to take into account the findings obtained
during the Assignment as the works progress and will be presented in separate
documents.
1.3
Project
Description
1.3.1
Background to the Study
Since December 1992, the East of Sha Chau area has been the site
of a series of dredged CMPs designed to provide
confined marine disposal capacity for contaminated mud arising from the HKSARs dredging and reclamation projects. The latest group of pits, CMP IVa, b & c began receiving contaminated mud from
construction projects on 1 December 1997.
CMP IVa was full by March 2000 (7.0 Mm3
of contaminated mud) and CMP IVb was full by May 2002
(12.5 Mm3 of contaminated mud).
CMP IVc is presently in operation for backfilling
by contaminated sediments.
As required by the Environment Protection Department
(EPD), an environmental monitoring and audit programme was carried out to
monitor the operation of the CMP IV under the Project Management and Capping
of Contaminated Mud Pit IV at East of Sha Chau. In this
connection, an environmental monitoring and audit programme which encompassed
water and sediment chemistry, fisheries assessment, tissue and whole body
analysis, sediment toxicity and benthic recolonisation
studies have been continuously carried out since the operation of CMP IV. A review of the collection and analysis of
such environmental data from the monitoring programme demonstrated that there
had not been any adverse environmental impacts resulting from disposal
activities ([1])([2])([3])([4]).
Capacity to dispose of contaminated mud is
currently predicted to be exhausted by 2010 with the completion of backfilling
of CMP IVc at East of Sha Chau. When CMP IVc is full, a new environmentally acceptable disposal capacity
for essential arisings will be required. A capacity of 8 Mm3 has been
estimated as being needed to provide disposal capacity up to 2015. The assignment Strategic Assessment and Site Selection Study for Contaminated Mud
Disposal (Agreement CE 105/98) recommended a Contained Aquatic Disposal
facility (CAD - capped seabed pit such as those already used at East of Sha Chau) at Airport East ([5]).
The results and recommendations of CE 105/98 were presented to the
Advisory Council on the Environment (ACE) on 23 July 2001 (ACE Paper
4/2001). The study recommended that an
EIA be carried out.
The
results of the EIA indicated that a series of four seabed pits be constructed
at East of Sha Chau to meet
continuing contaminated sediment demands ([6]). This recommendation and the
EIA supporting it were endorsed by ACE on 11 July 2005 and the EIA was
subsequently approved by the Director of Environmental Protection (DEP) without conditions on 1 September 2005
(AEIAR-089/2005).
An Environmental Permit (EP-312/2008) was issued by
the Environmental Protection Department (EPD) to the CEDD, the Permit Holder,
on 9 September 2008 and varied on 28 November 2008 (EP-312/2008/A) for CMP V.
Under the requirements of Condition 3 of the EP (EP-312/2008) for CMP V, an EM&A programme
as set out in the Manual is required to be implemented. EM&A programmes
have been continuously carried out during the operation of the previous mud
pits. The proposed monitoring and audit
programme for CMP V is a continuation of the existing monitoring and audit
programme. The monitoring and audit
arrangement will integrate the monitoring requirements for CMP IV and CMP
V. In this regard, the programme will
assess the impacts resulting from disposal and capping of CMP IV and from
dredging, disposal and capping of CMP V.
1.3.2
Contaminated Mud Disposal Operations at
East of Sha Chau
The dredging, backfilling and capping of CMP V
is classified as a Designated Project by virtue of Item C (Reclamation,
Hydraulic and Marine Facilities, Dredging and Dumping), Item C.10 (A Marine
Dumping Area) and C.12 (A Dredging Operation Exceeding 500,000 m3)
of Part I of Schedule 2 under the Environmental
Impact Assessment Ordinance (Cap. 499) (EIAO).
The key components of the construction and operation of
CMP V include the following:
i.
Dredging
of a series of seabed pits at CMP V within the proposed facility boundaries at
East of Sha Chau (Figure 1.1);
ii.
Backfilling
each dredged pit at CMP V with contaminated mud that has been classified as
requiring Type 2 disposal in accordance with ETWBTC 34/2002 ([7]); and,
iii.
Capping
each backfilled pit at CMP V with uncontaminated mud effectively isolating the
contaminated mud from the surrounding marine environment.
The key components for the operation of
CMP IV include the following:
i.
Disposal
of contaminated mud into Pit IVc that has been
classified as requiring Type 2 disposal in accordance with ETWBTC 34/2002 ([8]); and,
ii.
Capping
backfilled CMP IV with uncontaminated mud, effectively isolating the
contaminated mud from the surrounding marine environment.
1.3.3
Construction
Programme
It is expected that CMP IVc
will be active until March 2011 and capping will start in April 2011. Dredging for the first pit at CMP V commenced
in September 2009 in order to be ready to receive contaminated mud in mid
2011. According to the arising
estimates, the fourth pit of CMP V (CMP Vd) at the
East of Sha Chau Facility
will be backfilled and capped during the first half of 2015. It should be noted that should the rate at
which contaminated mud arises change (either increasing or decreasing) then CMP
Vd may be capped earlier or later.
1.4
Background to the
EM&A Programme
The construction and operational impacts resulting
from the implementation of CMP IV and V are specified in the respective EIA
Reports. The EIA Report also specifies
mitigation measures that need to be implemented to ensure compliance with the
required environmental criteria. These
mitigation measures and their implementation requirements are presented in the
Implementation Schedule (Annex
A). The EIAs
recommend that environmental monitoring will be necessary to assess the
effectiveness of measures implemented to mitigate potential water quality,
marine ecology and fisheries impacts during the construction and operation of
the proposed facility. Regular
environmental auditing is also recommended to ensure that potential impacts
from other sources are adequately addressed through the implementation of the
mitigation measures defined in the EIA Reports.
This Manual provides the EM&A requirements that
have been recommended in the EIA Reports for CMP IV and V in order to ensure
compliance with the specified mitigation measures.
1.5
The Scope of the
EM&A Programme
The scope of this EM&A programme is to:
·
establish
baseline water quality levels at specified locations prior to dredging
operations for the construction of CMP V at Sha Chau;
·
implement
monitoring and inspection requirements for water quality monitoring programme
during backfilling and capping of CMP IV and during dredging, backfilling and
capping operations of CMP V;
·
implement
monitoring and inspection requirements for sediment quality monitoring
programme during backfilling operations at CMP IV and CMP V;
·
implement
monitoring and inspection requirements for sediment toxicity monitoring
programme during backfilling operations at CMP IV and CMP V;
·
implement
monitoring and inspection requirements for the body burden (marine biota)
monitoring programme during backfilling operations at CMP IV and CMP V;
·
liaise
with, and provide environmental advice (as requested or when otherwise necessary)
to site staff on the comprehension and consequences of the environmental
monitoring data;
·
identify
and resolve environmental issues and other functions as they may arise from the
works;
·
check
and quantify the Contractor's overall environmental performance, implementation
of Event and Action Plans (EAPs), and remedial
actions taken to mitigate adverse environmental effects as they may arise from
the works;
·
conduct
monthly reviews of monitored impact data as the basis for assessing compliance
with the defined criteria and to ensure that necessary mitigation measures are
identified and implemented, and to undertake additional ad hoc monitoring and auditing as required by special
circumstances;
·
evaluate
and interpret all environmental monitoring data to provide an early indication
should any of the environmental control measures or practices fail to achieve
the acceptable standards, and to verify the environmental impacts predicted in
the EIA;
·
manage
and liaise with other individuals or parties concerning other environmental
issues deemed to be relevant to the construction and operation process; and,
·
conduct
regular site inspections of a formal or informal nature to assess:
-
the
level of the Contractors general environmental awareness;
-
the
Contractors implementation of the recommendations in the EIA;
-
the
Contractors performance as measured by the EM&A;
-
the
need for specific mitigation measures to be implemented or the continued usage
of those previously agreed;
-
to
advise the site staff of any identified potential environmental issues; and,
-
submit regular EM&A reports which summarise project
monitoring and auditing data, with full interpretation illustrating the
acceptability or otherwise of any environmental impacts and identification or
assessment of the implementation status of agreed mitigation measures.
1.5.1
Environmental Management Plan (EMP)
To
ensure effective implementation and reporting on compliance with the stated
mitigation measures, as well as the monitoring and auditing requirements and
remedial actions defined in the EIA, an appropriate contractual and supervisory
framework needs to be established. The
basis of the framework within which implementation should be managed overall is
through the preparation of EMPs
by the Contractor(s).
An
EMP is similar in nature to a quality plan and provides details of the means by
which the Contractor (and all subcontractors working to the Contractor) will
implement the recommended mitigation measures and achieve the environmental
performance standards defined in
The
EMP also provides opportunities for the Contractor to draw upon the strength of
other institutional processes such as ISO 9000/14000 to ensure that the
achievement of the required standards and fulfilment of commitments are
documented.
The
contractual requirement for an EMP would generally comprise appropriate
extracts from (and references to) the EIA Report and EM&A Manual, and
include such typical elements as the relevant statutory environmental
standards, general environmental control clauses and specific environmental
management clauses, as well as an outline of the scope and content of the
EMP. In drafting the documentation, due
consideration should be given to the predictive nature of the EIA process and
the consequent need to manage and accommodate the actual impacts arising from
the construction process. In particular,
the Contractor must be placed under a clear obligation to identify and control
any implications arising from changes to the working methods assumed in the
EIA, or to the progress rates and other estimates made during the preliminary
design phase.
1.6
Objectives of the
EM&A Programme
The objectives of the EM&A programme are as
follows:
1.
To monitor and report on the environmental impacts
of the dredging operations associated with the construction of the disposal
pits at CMP V.
2.
To monitor and report on the environmental impacts
due to capping operations of the exhausted pits at CMP IV and V.
3.
To monitor and report on the environmental impacts
of the disposal of contaminated marine sediments in the active pits at CMP IV
and V, specifically to determine:
·
changes/trends caused by disposal activities in the
concentrations of contaminants in sediments adjacent to the pits;
·
changes/trends caused by disposal activities in the
toxicity of sediment adjacent to the pits;
·
changes/trends caused by disposal activities in the
concentrations of contaminants in tissues of demersal
marine life adjacent to and remote from the pits;
·
impacts on water quality and benthic ecology caused
by the disposal activities; and
·
the risks to human
health and dolphin of eating seafood taken in the marine area around the active
pits.
4.
To monitor and report on the environmental impacts
of the disposal operation at CMP IV and V and specifically to determine whether
the methods of disposal are effective in minimising the risks of adverse
environmental impacts.
5.
To monitor and report on the benthic recolonisation of the capped pits at CMP IV and V and
specifically to determine the difference in infauna
between the capped pits and adjacent sites.
6.
To assess the impact of a major storm (Typhoon
Signal No. 8 or above) on the containment of any uncapped or partially capped
pits at CMP IV and V.
7.
To design and continually review the operation and
monitoring programme and:
·
to make recommendations for changes to the operation
that will rectify any unacceptable environmental impacts; and
·
to make
recommendations for changes to the monitoring programme that will improve the
ability to cost effectively detect environmental changes caused by the disposal
activities.
8.
To establish numerical decision criteria for
defining impacts for each monitoring component.
9.
To provide supervision on the field works and laboratory
works to be carried out by contractors/laboratories.
The specific objectives of each component are
discussed in the relevant sections of this EM&A Manual.
1.7
Organisation and
Structure of the EM&A
1.7.1
General
The Civil Engineering and Development Department
(CEDD) will appoint an Environmental Team (ET) to conduct the monitoring and
auditing works and to provide specialist advice on the undertaking and
implementation of environmental responsibilities.
The ET will have previous relevant
experience with managing similarly sized EM&A programmes and the
Environmental Team Leader (ET Leader) will be a recognised environmental
professional, preferably with a minimum of seven years relevant experience in
impact assessments and impact monitoring programmes.
To maintain strict control of the EM&A
process, the ET will also appoint independent auditor(s) to verify and validate
the environmental performance of the Contractor and the ET.
1.7.2
Project Organisation
The roles and responsibilities of the
various parties involved in the EM&A process are further expanded in the
following sections. The ET Leader will
be responsible for, and in charge of, the Environmental Team; and will be the
person responsible for executing the EM&A requirements.
Contractor
Reporting to CEDD, the Contractor will:
·
work
within the scope of the construction contract and other tender conditions;
·
provide
assistance to the ET in conducting the required environmental monitoring;
·
participate
in the site inspections undertaken by the ET, as required, and undertake any
corrective actions instructed by CEDD;
·
provide
information/advice to the ET regarding works activities which may contribute,
or be contributing to the generation of adverse environmental conditions;
·
implement
measures to reduce impact where Action and Limit levels are exceeded; and
·
take responsibility and strictly adhere to the guidelines of the EM&A
programme and complementary protocols developed by their project staff.
Civil Engineering and Development Department (CEDD)
CEDD will:
·
monitor
the Contractor's compliance with contract specifications, including the
effective implementation and operation of environmental mitigation measures and
other aspects of the EM&A programme;
·
comply
with the agreed Event and Action Plan in the event of any exceedance;
and
·
instruct the Contractor to follow the agreed protocols or
those in the Contract Specifications in the event of exceedances
or complaints.
Environmental Team
The duties of the Environmental Team (ET)
and Environmental Team Leader (ET Leader) are to:
·
monitor
the various environmental parameters as required by this or subsequent
revisions to the EM&A Manual;
·
assess
the EM&A data and review the success of the EM&A programme determining
the adequacy of the mitigation measures implemented and the validity of the EIA
predictions as well as identify any adverse environmental impacts before they
arise;
·
conduct
regular site inspections and to investigate and inspect the Contractor's
equipment and work methodologies with respect to pollution control and
environmental mitigation, monitor compliance with the environmental protection
specifications in the Contract, and to anticipate environmental issues that may
require mitigation before the problem arises;
·
audit
the environmental monitoring data and report the status of the general site
environmental conditions and the implementation of mitigation measures
resulting from site inspections;
·
review
Contractors working programme and methodology, and comment as necessary;
·
investigate
and evaluate complaints, and identify corrective measures;
·
advice
to the Contractor on environmental improvement, awareness, enhancement matters,
etc, on site;
·
employ
an Independent Auditor(s) to audit the results of the EM&A works carried
out by the ET;
·
report
on the environmental monitoring and audit results and the wider environmental
issues and conditions to the Contractor, CEDD and the EPD; and
·
adhere to the agreed protocols or those in the Contract
Specifications in the event of exceedances or
complaints.
The ET will be led and managed by the ET
leader. The ET leader will have relevant
education, training, knowledge, experience and professional qualifications
subject to the approval of the Director of Environmental Protection. Suitably qualified staff will be included in
the ET, and ET should not be in any way an associated body of the Contractor.
1.8
Structure of the
EM&A Manual
The remainder of the Manual is set out as
follows:
·
Section 2 sets out the EM&A general requirements;
·
Section
3 details the
methodologies, parameters to be tested and the requirements for the marine
water quality monitoring for the dredging, backfilling and capping operations
at the active pits;
·
Section
4 details the
methodologies, parameters to be tested and the requirements for sediment
quality monitoring for the backfilling activities at the active pits;
·
Section
5 details the
methodologies, parameters to be tested and the requirements for sediment
toxicity quality monitoring for the backfilling activities at the active pits;
·
Section
6 details the
methodologies, parameters to be tested and the requirements for marine biota
monitoring for the backfilling activities at the active pits;
·
Section 7 details the requirements for Human Health and Dolphin
Risk Assessment;
·
Section
8 details the
requirements for benthic re-colonisation assessment;
·
Section
9 details the
methodologies, parameters to be tested and the requirements for the assessment
of impacts due to major storms; and
·
Section 10 details the EM&A reporting requirements.
2
EM&A
GENERAL REQUIREMENT
2.1
Introduction
In this section, the general requirements
of the EM&A programme are presented with reference to the EIA Study findings
that have formed the basis of the scope and content of the programme.
2.2
EM&A
Key environmental issues associated with
the construction and operation of the Project will be addressed through
monitoring and controls specified in the EM&A Manual. Water and sediment quality, marine ecology
and fisheries issues will be subject to EM&A, the details of which are
outlined in Sections 3 to
9.
2.2.1
Action and Limit Levels
Action and Limit (A/L) Levels are defined levels of
impact recorded by the environmental monitoring activities which represent
levels at which a prescribed response is required. These levels only relate to CMP V. This processes by which these levels should
be quantitatively defined are presented in the relevant sections of this manual
and described in principle below:
·
Action Limits: beyond which there is a clear indication of a
deteriorating ambient environment for which appropriate remedial actions are
likely to be necessary to prevent environmental quality from falling outside
the Limit Levels, which would be
unacceptable; and
·
Limit Levels: statutory and/or agreed contract limits stipulated
in the relevant pollution control ordinances, HKPSG or Environmental Quality Objectives established by the EPD. If these are exceeded, works should not proceed
without appropriate remedial action, including a critical review of plant and
working methods.
2.2.2
Event and Action Plan
The purpose of an Event and Action Plan (EAP) is to
provide, in association with the monitoring and audit activities, procedures
for ensuring that if any significant environmental incident (either accidental
or through inadequate implementation of mitigation measures on the part of the
Contractor) does occur, the cause will be quickly identified and remediated,
and the risk of a similar event recurring is reduced. This also applies to the exceedances
of A/L criteria to be identified in the EM&A programme. As with the Action and Limit Levels, the
Event and Action Plan only relates to CMP V.
2.2.3
Enquiries, Complaints and Requests for
Information
Enquiries, complaints and requests for
information can be expected from a wide range of individuals and organisations
including members of the public, Government departments, the press and
television media and community groups.
All enquiries concerning the environmental
effects of the Project (CMP IV and V), irrespective of how they are received,
will be reported to CEDD and directed to the ET Leader who will set up
procedures for handling, investigation and storage of such information. The following steps will then be followed:
1)
The
ET Leader will notify CEDD of the nature of the enquiry.
2)
An
investigation will be initiated to determine the validity of the complaint and
to identify the source of the problem.
3)
The ET
Leader will undertake the following steps, as necessary:
·
investigate
and identify source of the problem;
·
if
considered necessary by CEDD undertake additional monitoring to verify the
existence and severity of the alleged complaint;
·
liaise
with EPD to identify remedial measures;
·
liaise
with CEDD and the Contractor to identify remedial measures;
·
implement
the agreed mitigation measures;
·
repeat
the monitoring to verify effectiveness of mitigation measures; and
·
repeat review procedures to identify further possible areas
of improvement if the repeat monitoring results continue to substantiate the
complaint.
4)
The
outcome of the investigation and the action taken will be documented on a
complaint proforma (Annex B). A
formal response to each complaint received will be prepared by the ET Leader
within a maximum of five working days and submitted to CEDD, in order to notify
the concerned person(s) that action has been taken.
5)
All
enquiries which trigger this process will be reported in the EM&A reports
which will include results of inspections undertaken by the ET Leader, and
details of the measures taken, and additional monitoring results (if deemed
necessary). It should be noted that the
receipt of complaint or enquiry will not be, in itself, a sufficient reason to
introduce additional mitigation measures.
In all cases the complainant will be
notified of the findings, and audit procedures will be put in place to ensure
that the problem does not recur.
2.2.4
Reporting
Monthly, Quarterly and Annual reports for
CMP IV and V will be submitted to CEDD, EPD and AFCD and will be prepared by
the ET. The reports will be prepared and
submitted within a specified period. Additional
details on reporting protocols are presented in Section 10.
3
Water Quality
3.1
Introduction
This Section provides details of the water quality
monitoring to be undertaken during the construction and operation of the active pits. Water quality modelling carried out for the
EIA indicates that the potential water quality impacts associated with the
backfilling and capping works at CMP IV and dredging, backfilling and capping
works at CMP V will be within acceptable levels and no adverse water quality
impacts are expected. However, the
monitoring programme is designed to verify the predictions of the EIA and
ensure compliance with the WQOs.
3.2
Monitoring
Activities
Water quality monitoring for the Project can be
divided into the following stages:
·
Dredging
Activities for CMP V;
·
Backfilling
Activities for CMP IV and V; and
·
Capping
Activities for CMP IV and V.
Each of these is discussed in turn below.
3.3
Monitoring for
Dredging Activities of CMP V
Water
quality monitoring will be conducted during dredging of four seabed pits for
CMP V at Sha Chau. Monitoring will consist of the collection of
baseline water quality data for the purposes of the development of Action and
Limit Levels, as well as impact monitoring of actual dredging activities.
3.3.1
Baseline Monitoring for Dredging
Activities of CMP V
Baseline
monitoring for dredging activities will be conducted in the vicinity of the new facility at Sha Chau and in reference areas (EPD Water Quality
Monitoring Stations NM1, 2, 3, 5 and 6) for a period of four weeks prior to the
commencement of marine dredging works in order to gather representative water
quality data for the EM&A. Locations
of the baseline monitoring stations are shown in Figure 3.1 and the coordinates are shown in Table 3.1.
The
baseline water
quality monitoring will be undertaken three days per week at all stations
within a 3 hour window of 1.5 hours before or after mid-flood and mid-ebb tides
for four weeks prior to construction works commencing. The interval between two sampling surveys
will not be less than 36 hours. A
sampling survey will include the collection of all water samples and
measurement of all in situ parameters
during both mid-flood and mid-ebb tides at all stations on the same day.
Table 3.3.1 Coordinates
of Water Quality Monitoring Stations for Baseline Water Quality Monitoring for
Dredging Activities
|
Monitoring Stations |
Eastings |
Northings |
|
Far Field
Stations |
|
|
|
ESC-WFA |
805787 |
827951 |
|
ESC-WFB |
806066 |
816537 |
|
MW1 |
823604 |
823654 |
|
Near Field
Stations |
|
|
|
ESC-WNAA |
811830 |
822706 |
|
ESC-WNAB |
810833 |
822965 |
|
ESC-WNAC |
810235 |
822756 |
|
ESC-WNAD |
809557 |
822527 |
|
ESC-WNBA |
812767 |
821889 |
|
ESC-WNBB |
811651 |
822278 |
|
ESC-WNBC |
811043 |
822178 |
|
ESC-WNBD |
810514 |
821919 |
|
Mid Field
Stations |
|
|
|
ESC-WMB |
814033 |
821082 |
|
ESC-WMA |
809577 |
823922 |
|
Reference Stations |
|
|
|
NM1 |
820256 |
823214 |
|
NM2 |
816015 |
823686 |
|
NM3 |
812527 |
824049 |
|
NM5 |
807707 |
827244 |
|
NM6 |
807584 |
820286 |
Each station will be
sampled and measurements will be taken at three depths, 1 m below the sea
surface, mid depth and 1 m above the seabed.
Where the water depth is less than 6 m the mid-depth station may be
omitted. If the water depth is less than
3 m, only the mid-depth station will be monitored.
The following suite of parameters should
be measured as part of the baseline monitoring:
·
Dissolved
Oxygen (mg L-1) (in situ);
·
Salinity
(ppt) (in situ);
·
pH (in situ);
·
Turbidity
(NTU) (in situ);
·
Temperature
(°C) (in situ);
·
Current
Velocity and Direction (ms-1) (in
situ);
·
Suspended
Solids (mg L-1) (laboratory analysis);
·
Ammonia
(mg L-1) (laboratory analysis);
·
Total
Inorganic Nitrogen (TIN mg L-1) (laboratory analysis);
·
5-Day
Biochemical Oxygen Demand (BOD) (mg L-1) (laboratory analysis);
·
Cadmium
(mg L-1) (laboratory analysis);
·
Chromium
(mg L-1) (laboratory analysis);
·
Copper
(mg L-1) (laboratory analysis);
·
Lead
(mg L-1) (laboratory analysis);
·
Mercury
(mg L-1) (laboratory analysis);
·
Nickel
(mg L-1) (laboratory analysis);
·
Silver
(mg L-1) (laboratory analysis);
·
Zinc
(mg L-1) (laboratory analysis); and,
·
Arsenic
(mg L-1) (laboratory analysis).
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, special phenomena
and work activities undertaken around the monitoring and works area that may
influence the monitoring results.
Four hard copies and one electronic copy
of the Baseline Monitoring Report will be submitted to EPD at least two weeks
before commencement of construction of the Project.
3.3.2
Impact Monitoring for Dredging Activities
of CMP V
Impact monitoring for the dredging activities to form
CMP V will be conducted at mobile stations around the dredging area. Currently the impact monitoring is conducted
for three times per week and the monitoring frequency may be revised upon
agreement with the EPD. Monitoring will
be carried out during both mid-flood and mid-ebb tides on each monthly monitoring
day. The location of the mobile stations
is dependent on the location of the dredging activities. These mobile stations will be located at an
appropriate distance between each other along the up-current and down-current
transect for the dredging area. The
following methodology will be adopted to determine the precise location of the
mobile stations on each sampling occasion:
·
Contact the CEDD barge one day before the survey day for every sampling
occasion to determine the dredging schedule for that particular survey day and
to determine the likely location of dredging at the proposed time of sampling;
·
Determine current direction at mid-depth at one
station upstream and one station downstream of the new facility during both
mid-flood and mid-ebb tide. Upstream station
will be 100 m upstream and the downstream station will be 100 m downstream of
the dredging area of CMP V;
·
Determine a suitable location for the station transect (the first
down-current station will be located on the down current edge, and first up-current
station will be located on the up-current edge, of the CMP V according to the
current direction and the position of dredging at the time of sampling); and,
·
Collect samples from the stations located on a transect running up-current and down-current of the
dredging area.
There
will be two stations located up-current and five stations down-current of CMP V
on the transect.
A 500 m separation distance will be adopted between adjacent stations
except between adjacent upstream and downstream stations which are located on
the pit edge. In addition, water samples
will be collected from the station MW1 as shown in Figure 3.2. Locations of upstream and downstream stations
are illustrated in Figure 3.2 based on assumed current
direction and dredging position during monitoring.
Each station will be
sampled and measurements will be taken at three depths, 1 m below the sea
surface, mid depth and 1 m above the seabed.
Duplicate water samples and measurements will be taken at each
depth. Where water depth is less than 6m
the mid-depth station may be omitted. If
water depth is less than 3m, only the mid-depth station will be monitored.
The following suite of parameters should
be measured as part of the impact monitoring for dredging:
·
Dissolved
Oxygen (mg L-1) (in situ);
·
Salinity
(ppt) (in situ);
·
pH (in situ);
·
Turbidity
(NTU) (in situ);
·
Temperature
(°C) (in situ)
·
Current
Velocity and Direction (ms-1) (in
situ); and,
·
Suspended
Solids (mg L-1) (laboratory analysis).
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, special phenomena and work activities undertaken
around the monitoring and works area that may influence the monitoring results.
3.3.3
Water Quality Compliance and Event &
Action Plan
Impact
monitoring for dredging activities of CMP V will be evaluated against Action
and Limit Levels. The key assessment
parameters are dissolved oxygen (DO) and suspended sediment (SS) and thus
Action and Limit Levels based on the assessment criteria are identified for
these parameters. However, turbidity can
also provide valuable instantaneous information on water quality and thus an
Action Limit is measured for this parameter to facilitate quick responsive
action in the event of any apparent unacceptable deterioration attributable to
the works.
The Action and Limit Levels for DO,
turbidity and SS were determined in the Baseline
Monitoring Report (1) according
to the criteria shown in Table 3.1. The Action and Limit Levels of DO, turbidity
and SS were derived from the baseline monitoring data ([9]) and they are presented in Table 3.2.
Action
and Limit levels are used to determine whether modifications are necessary to
mitigate impacts to water quality. In the
event that the levels are exceeded, appropriate actions in Event and Action
Plan (Table 3.3) should be
undertaken.
Table
3.1 Determination
of Action and Limit Level of Water Quality for Dredging, Capping and
Backfilling Activities of CMP V
|
Parameter |
Action Level |
Limit Level |
|
Dissolved
Oxygen |
|
|
|
Surface
and Middle Depth
Averaged |
The
depth average of the impact station readings are <5%ile of baseline data and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
The
average of the impact station readings are <4mg/L and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
|
Bottom |
The
average of the impact station readings are <5%ile of baseline data and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
The
average of the impact station readings are <2mg/L and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
|
Suspended
Solids |
|
|
|
Depth
Averaged |
The
depth average of the impact station readings are >95%ile of baseline data and 120%
or more of the reference stations SS (at the same tide of the same day) |
The
depth average of the impact station readings are >99%ile of baseline data and 130%
or more of the reference stations SS (at the same tide of the same day) |
|
Turbidity |
|
|
|
Depth
Averaged |
The
depth average of the impact station readings are >95%ile of baseline data and 120%
or more of the reference stations turbidity (at the same tide of the same
day) |
The
depth average of the impact station readings are >99% of baseline data and
130%
or more of the reference stations turbidity (at the same tide of the same
day) |
Table
3.2 Action
and Limit Levels of Water Quality for Dredging, Capping and Backfilling
Activities of CMP V.
|
Parameter |
Action Level |
Limit Level |
|
Dissolved Oxygen (DO) (1) |
|
|
|
Surface
and Middle Depth
Averaged (2) |
5%-ile
of baseline data for surface and middle layer = 3.76 mg L-1 and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
1%-ile
of baseline data for surface and middle layer = 3.11 mg L-1 (3) and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
|
|
|
|
|
Bottom |
5%-ile
of baseline data for bottom layers = 2.96 mg L-1 and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
The
average of the impact station readings are <2 mg/L and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
|
|
||
|
|
|
|
|
Depth-averaged Suspended Solids (SS) (4) (5) |
95%-ile of baseline data for depth average =
37.88 mg L-1 and |
99%-ile of baseline data for depth average =
61.92mg L-1 and |
|
|
120% of control station's SS at the same tide of
the same day |
130% of control station's SS at the same tide of
the same day |
|
|
|
|
|
Depth-averaged Turbidity (Tby)
(4) (5) |
95%-ile of baseline data = 28.14 NTU and |
99%-ile of baseline data = 38.32 NTU and |
|
|
120% of control station's turbidity at
the same tide of the same day |
130% of control station's turbidity at
the same tide of the same day |
|
|
|
|
|
Notes: (1)
For
DO, non-compliance of the water quality limits occurs when monitoring result
is lower than the limits. (2)
The
Action and Limit Levels for DO for Surface & Middle layers were
calculated from the combined pool of baseline surface layer data and baseline
middle layer data. (3)
Given
the Action Level for DO for Surface
& Middle layers has already been lower than 4 mg L-1, it
is proposed to set the Limit Level at
3.11 mg L-1 which
is the first percentile of the baseline data. (4)
Depth-averaged
is calculated by taking the arithmetic means of reading of all three depths. (5)
For
turbidity and SS, non-compliance of the water quality limits occurs when
monitoring result is higher than the limits. |
||
Table 3.3 Water
Quality Event and Action Plan during Dredging Operations
|
Event |
Environmental Team (ET) |
Contractor |
|
Action Level |
|
|
|
Exceedance for one sample |
·
Repeat
in-situ measurement to confirm findings; ·
Identify
the source(s) of impact; ·
Inform
contractor and contractor informs CEDD, EPD and AFCD and confirm notification
of the non-compliance in writing; ·
Check
monitoring data; ·
Discuss
potential mitigation measures if exceedance is
attributed to the works with contractor. |
·
Discuss
potential mitigation measures with ET and agree on mitigation measures to be
implemented if exceedance is attributed to the
works; ·
Ensure
mitigation measures are implemented; ·
Assess
the effectiveness of the implemented mitigation measures. |
|
Limit Level |
|
|
|
Limit
level for one occasion |
·
Repeat
in-situ measurement to confirm findings; ·
Identify
source(s) of impact; ·
Inform
contractor and contractor informs CEDD, EPD and AFCD; ·
Discuss
further mitigation measures if exceedance is attributed
to the works with contractor; ·
Increase
the monitoring frequency to daily if exceedance is
attributed to the works until no exceedance of the
Limit Level. |
·
Critical
review of working methods; ·
Check
plant, equipment and working methods; ·
Discuss
further mitigation measures with ET to be implemented if exceedance
is attributed to the works; ·
Ensure
mitigation measures are being implemented; ·
Assess
the effectiveness of the implemented mitigation measures. |
|
|
|
|
|
Limit
Level exceeded on two or more occasions |
·
Identify
source(s) of impact; ·
Inform
contractor and contractor informs, CEDD, EPD and AFCD. |
·
If exceedance is attributed to the works consider and if
necessary reduce works until no exceedance of Limit
Level. |
|
|
|
|
|
Impacts
attributable to works |
·
Inform
contractor and contractor informs, CEDD, EPD and AFCD. |
·
Comprehensive
review of works; ·
Reduce
works; and ·
Suspension
of works. |
3.4
Monitoring for
Backfilling Activities
3.4.1
Objective
The main objective of this component is to
determine the impacts, if any, of backfilling activities at CMP IV and V on
water quality. Two separate components
of water quality monitoring are necessary during backfilling:
·
Routine Water Quality Monitoring - Conducted to examine the impacts of
disposal activities on the level of inorganic metal contaminants in marine
waters; and,
·
Water Column Profiling - conducted to examine in situ the effects of backfilling
operations on water quality parameters within the water column.
3.4.2
Hypotheses
The impact hypothesis for this work
component has been defined based on the predictions from the EIA regarding
impacts from the contaminated mud disposal operations and the objectives for
the study.
Backfilling
operations do not result in any exceedances of Northwestern Water Quality Control Zone (NWQCZ) Water
Quality Objectives (WQO).
As a consequence of performing two
separate tasks for assessing the impacts of disposal operations on water
quality, two null hypotheses will be tested:
Routine
Water Quality Monitoring
H0 There
are no differences in the levels of contaminants in water samples in the plume
arising from the disposal works and background levels in the vicinity of the
backfilling.
Water
Column Profiling
H0 There
is no change in the level of compliance with the NWWCZ WQOs
of samples taken from the plume arising from backfilling activities (EIA
predicted location).
3.4.3
Sampling Design
Routine Water Quality Monitoring
Routine water quality monitoring will be
undertaken during backfilling activities at mid-ebb or mid-flood tide. Water samples will be collected at specific
stations at fixed location, which should be located in three areas at
increasing distances from the active facility; Reference, Intermediate and
Impact stations/areas. The design for
this component of the programme allows impacts, if any, to water quality as a
result of the backfilling activities in the vicinity of CMP IV and V to be
assessed.
The number of monitoring stations sampled depends
on the state of the tide. During the ebb
tide, water samples are collected from five up-current Reference Stations, five
down-current Impact Stations and five down-current Intermediate Stations. During the flood tide, water samples are
collected from three up-current Reference Stations, three down-current Impact
Stations and three down-current Intermediate Stations. The approach will ensure that the impact of
temporal changes on the hydrodynamic conditions in the area is considered in
the sampling.
The following suite of parameters should be measured
as part of routine water quality monitoring operations:
·
Dissolved
Oxygen (mg L-1) (in situ);
·
Salinity
(ppt) (in situ);
·
pH (in situ);
·
Turbidity
(NTU) (in situ);
·
Temperature
(°C) (in situ)
·
Current
Velocity and Direction (ms-1) (in
situ);
·
Suspended
Solids (mg L-1) (laboratory analysis);
·
Ammonia
(mg L-1) (laboratory analysis);
·
Total
Inorganic Nitrogen (TIN mg L-1) (laboratory analysis);
·
5-Day
Biochemical Oxygen Demand (BOD5) (mg L-1) (laboratory
analysis)
·
Cadmium
(mg L-1) (laboratory analysis);
·
Chromium
(mg L-1) (laboratory analysis);
·
Copper
(mg L-1) (laboratory analysis);
·
Lead
(mg L-1) (laboratory analysis);
·
Mercury
(mg L-1) (laboratory analysis);
·
Nickel
(mg L-1) (laboratory analysis);
·
Silver
(mg L-1) (laboratory analysis);
·
Zinc
(mg L-1) (laboratory analysis); and
·
Arsenic
(mg L-1) (laboratory analysis).
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, special phenomena and work activities undertaken around the monitoring
and works area that may influence the monitoring results.
Sampling for CMP IV
For CMP IV the locations of stations during ebb and
flood tides are shown in Figures
3.3 and 3.4, respectively, and the coordinates
are shown in Table 3.4. Sampling should be undertaken at each
station for two times per year, once in the dry season and once in the wet
season. For a given sampling event water
samples and in situ measurements
should be taken at mid-depth of all stations during the same tidal state (ie mid-ebb or mid-flood tide). The Long-term
Review of Environmental Monitoring for Contaminated Mud Pits ([10])
determined that this sampling
frequency is adequate to track potential changes in contaminant concentrations
of seawater which may take a long time to appear, while at the same time
addressed the potential seasonal difference in seawater quality.
Table 3.4 Coordinates
of Water Quality Monitoring Stations for Capping and Routine Water Quality
Monitoring for CMP IVc
|
Monitoring Stations |
Eastings |
Northings |
|
Ebb |
|
|
|
Reference Stations |
|
|
|
RFE1 |
808527 |
822762 |
|
RFE2 |
808736 |
823066 |
|
RFE3 |
808956 |
823390 |
|
RFE4 |
809176 |
823715 |
|
RFE5 |
809427 |
824008 |
|
Impact Stations |
|
|
|
IPE1 |
811658 |
821212 |
|
IPE2 |
812716 |
821107 |
|
IPE3 |
812412 |
821453 |
|
IPE4 |
812475 |
821851 |
|
IPE5 |
812894 |
822050 |
|
PFC1 |
810328 |
820961 |
|
Intermediate Stations |
|
|
|
INE1 |
808066 |
821045 |
|
INE2 |
808380 |
820772 |
|
INE3 |
808862 |
820280 |
|
INE4 |
808495 |
819725 |
|
INE5 |
809155 |
820793 |
|
Flood |
|
|
|
Reference Stations |
|
|
|
RFF1 |
807608 |
820633 |
|
RFF2 |
812126 |
821111 |
|
RFF3 |
813233 |
821127 |
|
·
Impact Stations |
·
|
·
|
|
IPF1 |
809104 |
822250 |
|
IPF2 |
809721 |
822598 |
|
IPF3 |
810860 |
823706 |
|
PFC1 |
810623 |
823484 |
|
·
Intermediate Stations |
·
|
·
|
|
INF1 |
808775 |
823012 |
|
INF2 |
809096 |
823328 |
|
INF3 |
809571 |
823816 |
|
PFC2 |
810109 |
824272 |
Note: Coordinates are based on
Three replicate
samples for Zinc and BOD5, and two replicate samples for all other
metals, Ammonia (NH3), TIN and SS will be collected from each of the monitoring stations
during each sampling event. This number
of replicate samples for CMP IVc was determined from
a power analyses that evaluated the cost efficiency and effectiveness of this EM&A
programme (1).
Routine water quality monitoring will be
undertaken for CMP IVc which will be active until
March 2011 based on current predictions.
Details on the Sampling
Programme for CMP IV are shown in Table C1 of Annex C.
Sampling for CMP V
The locations of stations during ebb and
flood tides for CMP V are shown in Figures 3.5 and 3.6,
respectively, and the coordinates are shown Table 3.5. An
additional monitoring station at Ma Wan will be sampled for CMP V. Eight replicate samples should be
collected from each monitoring station for eight times per year, twice in the
dry season, twice during the wet season and twice in each of the two
transitional seasons. The sampling frequency
and number of replicates are the same as those used at the start of CMP IV
monitoring (1) and will initially be used for CMP V monitoring as a
consistent and conservative approach.
For a given sampling event water samples and in situ measurements should be taken at mid-depth of all stations
during the same tidal state (ie mid-ebb or mid-flood
tide). Sampling frequency and number of
replicates for CMP V will be reviewed and adjusted accordingly based on power
analyses in each Annual Review Report.
Routine water quality monitoring for CMP V
will be undertaken during its backfilling activities, which is currently
predicted to begin in March 2011. Details on the Sampling Programme for
CMP V are shown in Table C2 of Annex C.
Table 3.5 Coordinates
of Water Quality Monitoring Stations for Capping and Routine Water Quality
Monitoring for CMP V
|
Monitoring Stations |
Eastings |
Northings |
|
Ebb |
|
|
|
Reference Stations |
|
|
|
ESC-RFE1 |
808527 |
822762 |
|
ESC-RFE2 |
808736 |
823066 |
|
ESC-RFE3 |
808956 |
823390 |
|
ESC-RFE4 |
809176 |
823715 |
|
ESC-RFE5 |
809427 |
824008 |
|
Impact Stations |
|
|
|
ESC-IPE1 |
810121 |
821674 |
|
ESC-IPE2 |
810814 |
822136 |
|
ESC-IPE3 |
811763 |
821931 |
|
ESC-IPE4 |
812430 |
821717 |
|
ESC-IPE5 |
812894 |
822050 |
|
Intermediate Stations |
|
|
|
ESC-INE1 |
808066 |
821045 |
|
ESC-INE2 |
808380 |
820772 |
|
ESC-INE3 |
808862 |
820280 |
|
ESC-INE4 |
808495 |
819725 |
|
ESC-INE5 |
809155 |
820793 |
|
Ma Wan Station |
|
|
|
MW1 |
823604 |
823654 |
|
Flood |
|
|
|
Reference Stations |
|
|
|
ESC-RFF1 |
807608 |
820633 |
|
ESC-RFF2 |
812126 |
821111 |
|
ESC-RFF3 |
813233 |
821127 |
|
Impact Stations |
|
|
|
ESC-IPF1 |
809862 |
823353 |
|
ESC-IPF2 |
809293 |
822799 |
|
ESC-IPF3 |
810432 |
823907 |
|
Intermediate Stations |
|
|
|
ESC-INF1 |
808346 |
823213 |
|
ESC-INF2 |
809013 |
823843 |
|
ESC-INF3 |
809680 |
824473 |
|
Ma Wan Station |
|
|
|
MW1 |
823603 |
823653 |
Note: Coordinates are based on
Water Column Profiling
Water column profiling will be undertaken
during backfilling activities. For both
CMP IV and V, there are two monitoring stations for Water Column
Profiling. Their locations are mobile,
and will be dependent on the position of the disposal barge at the time of
monitoring. The two mobile monitoring
stations will be approximately 100 m upstream and downstream of the disposal
area, respectively.
The following suite of parameters should
be measured as part of the water column profiling:
·
Salinity
(ppt) (in situ);
·
Dissolved
Oxygen (mg L-1) (in situ);
·
Turbidity
(NTU) (in situ);
·
Temperature
(°C) (in situ)
·
Current
Velocity and Direction (ms-1) (in
situ)
·
pH (in situ); and
·
Suspended
Solids (mg L-1) (laboratory analysis).
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, special phenomena and work
activities undertaken around the monitoring and works area that may influence
the monitoring results.
Sampling for CMP IV
Water
Column Profiling for CMP IVc will be conducted six
times per year, three times during the wet season and three times during the
dry season. Two replicate samples for SS
will be collected at mid-depth from each of the monitoring stations during each
sampling event. This level of
replication for CMP IV was found to be sufficient in power analyses that evaluated the cost efficiency and effectiveness of the EM&A programme (1). In addition, during each
sampling event in
situ measurements should be taken at 1 m depth intervals through
the water column for a period of one hour at each station. All water samples and in situ measurements should be taken during the same tidal state (ie mid-ebb or mid-flood tide) of a given sampling
event. Details on the Sampling Programme for CMP IV are shown in Table
C1 of Annex C.
Sampling for CMP V
Water Column Profiling for CMP V will be
conducted monthly. Four replicate
samples for SS will be collected at mid-depth from each of the monitoring
stations during each sampling event.
This is the same number of replicates as those used at the start of CMP
IV monitoring (1) and will be initially used for CMP V monitoring as
a consistent and conservative approach. During each sampling event in situ measurements should be taken at 1 m depth
intervals through the water column for a period of one hour at each
station. All water samples and in situ measurements should be taken
during the same tidal state (ie mid-ebb or mid-flood
tide) of a given sampling event.
Sampling frequency and the number of replicates for CMP V will be
reviewed and adjusted accordingly based on power analyses in each Annual Report. Details
on the Sampling Programme for CMP V are shown in Table C2 of Annex C.
3.4.4
Statistical Treatment of Data
Routine Water Quality Monitoring
The hierarchy of sampling design should
allow for the application of nested analysis of variance to statistically test
any changes or trends in the dataset. Under
the nested design, differences will be tested between stations in a particular
area and between the three areas (ie Impact,
Intermediate and Reference). Once a time
series of data has been gathered temporal changes in water quality parameters
can be analysed for significant differences.
In addition, the data gathered will be examined against the water
quality objectives for the NWWCZ to determine if the relevant water quality
objectives have been exceeded.
Water Column Profiling
The data gathered will be examined
graphically against the water quality objectives for the NWWCZ to determine if
the relevant water quality objectives have been exceeded for any apparent
impacts arising from the backfilling activities.
3.4.5
Use of Data
Should increases be detected in the level
of contaminants or exceedances of the NWWCZ WQOs be detected, a review of the other monitoring
parameters will be undertaken. This will
focus on sampling stations in the vicinity of the water quality stations where
increases are detected to see if these can be attributed to contaminant spread
from the active pits. If so, consideration will be given to
revising the facility operations plan and backfilling activities to reduce the
spread of contaminants in the plume and achieve compliance with WQOs.
3.5
Monitoring for
Capping Activities
The design for this component of the
programme allows impacts to water quality as a result of the overall capping
activities of CMP IV and V to be assessed.
Replicate water samples will be collected at specific stations, which
should be located in three discrete areas: Impact, Intermediate and
Reference. The number of monitoring
stations sampled depends on the state of the tide. During the ebb tide, water samples will be
collected from five up-current Reference Stations, five down-current Impact
Stations and five down-current Intermediate Stations. During the flood tide, water samples will be
collected at three up-current Reference Stations, three down-current Impact
Stations and three down-current Intermediate Stations.
The following suite of parameters should
be measured as part of the impact monitoring for capping:
·
Dissolved
Oxygen (mg L-1) (in situ);
·
Salinity
(ppt) (in situ);
·
pH (in situ);
·
Turbidity
(NTU) (in situ);
·
Temperature
(°C) (in situ)
·
Current
Velocity and Direction (ms-1) (in
situ); and,
·
Suspended
Solids (mg L-1) (laboratory analysis).
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, special phenomena
and work activities undertaken around the monitoring and works area that may
influence the monitoring results.
Sampling for CMP IV
For CMP IV the locations of stations
during ebb and flood tides are shown in Figures 3.3 and 3.4,
respectively, and the coordinates are shown Table 3.4. Replicate samples will be collected from each
station four times per year, twice in the dry season and twice during the wet
season. Three replicate samples of SS
will be collected from mid-depth at each of the monitoring station during each
sampling event. In addition, in situ measurements should be taken at
1 m depth intervals through the water column at each station during a sampling
event. All water samples and in situ measurements should be taken
during the same tidal state (ie mid-ebb or mid-flood
tide) of a given sampling event.
Sampling will be undertaken during capping activities for CMP IV as detailed in the Sampling Programme for
CMP IV shown in Table C1 of Annex C. Capping
monitoring for CMP IV will cease once capping monitoring for CMP V has been
started as the capping monitoring for CMP V is designed to track the potential
plumes arise from concurrent CMP IV and V capping activities.
Sampling for CMP V
The locations of
stations during ebb and flood tides for CMP V are shown in Figures 3.5 and 3.6, respectively, and the coordinates
are shown Table 3.5. For CMP V, samples will be collected
from an additional station at Ma Wan, for both ebb and flood tides. Samples should be collected four times per
year, twice in the dry season and twice during the wet season. Three replicate samples of SS will be collected from mid-depth at each
monitoring station during each sampling event.
In addition, in situ measurements
should be taken at 1 m depth intervals through the water column at each station
during a sampling event. All water
samples and in situ measurements
should be taken during the same tidal state (ie mid-ebb
or mid-flood tide) of a given sampling event.
Sampling will be undertaken during capping activities for CMP V as detailed in the Sampling Programme for
CMP V shown in Table C2 of Annex C. Sampling
frequency and number of replicates for CMP V will be reviewed and adjusted
accordingly based on power analyses in each Annual
Report.
3.6
Sampling
Procedure for Water Quality monitoring
In situ water quality monitoring (salinity,
temperature, current velocity and direction) will be conducted using the
equipment listed in Section 3.6.1 and
following the testing protocols detailed in Section
3.6.2. In order to ensure the
reliability and quality of the data, the measuring instrument will be
calibrated prior to each sampling cruise and the probe of the measuring
instrument will be maintained at a suitable distance from the seabed to avoid
re-suspension of bottom sediments from skewing the results.
Water quality profiling will be conducted
continuously for a one-hour period from a fixed point. After deployment, the probe of the measuring
equipment will be allowed to equilibrate with the surrounding seawater for
approximately 30 seconds. Subsequently,
average readings will be taken every few seconds to minimise sampling noise
arising from the sensitivity of the equipment.
In addition to in situ water quality monitoring, water samples will be collected
in a water sampler. Samples will be stored
in sealed sampling bottles and chilled, and on completion of the survey will be
transported to the laboratory for immediate analysis. Samples not for immediate analysis will be
stored at 4 ± 2°C.
3.6.1
Equipment
The following equipment will be supplied and used by
the contractor for the water quality monitoring:
·
Positioning
Device - Horizontal
positioning will be used and determined by a differential Global Positioning
System (dGPS) with the differential signal being
provided by a UHF differential transmitter.
The UHF system should provide an accuracy of better than 3m at the 95%
confidence level to ensure the survey vessel is in the correct location before
taking measurements. The dGPS will be calibrated daily before each survey period or
results reported. And all data will be
printed and logged on disc.
·
Electronic
data logging device -
A data logging device capable of storing measurement data will be used. The device will be able to read and store the
output from all electronic meters used for this project and will record time
and location as measured by the GPS.
·
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 will have a membrane electrode with automatic
temperature compensation complete with a cable of not less than 20 m in
length. Sufficient stocks of spare
electrodes and cables will be available for replacement where necessary (for
example, YSI model 59 metre, YSI 5739 probe, YSI 5795A submersible stirrer with
reel and cable or an approved similar instrument).
·
Turbidity
Measurement Equipment
- Turbidity within the water will be measured in situ by the nephelometric method. The instrument will be a portable,
weatherproof turbidity-measuring unit complete with cable, sensor and
comprehensive operation manuals. The
equipment will be operated from a DC power source, it will have a photoelectric
sensor capable of measuring turbidity between 0 - 1000 NTU and will be complete
with a cable with at least 20 m in length (Hach 2100P
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.
·
pH meter A portable pH meter capable of measuring a range
between 0.0 and 14.0 will be provided to measure pH in marine waters.
·
Suspended
Solid Measurement Equipment - A water sampler
(eg Kahlsico Water Sampler),
which is a PVC cylinder (capacity not less than 2 litres) which can be
effectively sealed with latex cups at both ends, will be used for
sampling. The 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. Water samples for suspended solids
measurement will be collected in high density polythene bottles, packed in ice
(cooled to 4oC without being frozen), and delivered to the laboratory
in the same day as the samples were collected.
·
Water
Depth Gauge - A
portable, battery-operated echo sounder (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 programme.
·
Water
Sampling Equipment -
A water sampler, consisting of a transparent PVC or glass cylinder of not less
than two litres which can be effectively sealed with cups at both ends, will be
used (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.
·
Current
Velocity Measuring Equipment An NE Sensortec A/S UCM-60 current meter or Valeport 108 MKIII current meter or a similar approved
instrument will be used for measuring current direction. Current velocity is measured by ADCP. Calibration of ADCP is not likely to be
necessary for these instruments as they are calibrated for the life of the
instrument.
3.6.2
Sampling / Testing Protocols
The position of the
survey vessel will be positioned to within 3 m of the designated coordinates at
each monitoring station using a differential Global Positional System
(GPS).
All in situ
monitoring instruments will be checked, calibrated and certified by a
laboratory accredited under HOKLAS or any other international accreditation
scheme before use, and subsequently re-calibrated at three month intervals
throughout the stages of the water quality monitoring. Responses of sensors and electrodes will be
checked with certified standard solutions before each use.
On-site calibration of field equipment will follow
the Guide to Field and On-Site Test
Methods for the Analysis of Waters, BS 1427: 1993. Sufficient stocks of spare parts will be
maintained for replacements when necessary.
Backup monitoring equipment will also be made available so that
monitoring can proceed uninterrupted even when equipment is under maintenance,
calibration etc.
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.
At least two replicate samples should be collected
from each of the monitoring events for in
situ measurement and lab analysis.
3.6.3
Laboratory Procedures
Using chain of custody forms, collected
water samples will be transferred directly to laboratory for immediate
processing of suspended solids, ammonia, nutrients and BOD5. Water samples will be analysed for pH and BOD
within 4 hours of their arrival at the laboratory. All other parameters will be analysed within
48 hours of arrival. During this period
samples will be held at 4 ± 2șC.
Prior to subjecting the sample to metals analysis, samples will be
filtered to remove solids and colloidal matter.
Filtration will be accomplished using acid washed, single-use 0.45
micron membrane filters within a maximum of 8 hours from sample
collection. Where necessary, samples
will undergo further preparation involving preconcentration
which allows lower method detection limits to be achieved and removes some of
the possible sources of interference.
3.7
QA/QC
3.7.1
Field Logs
Field logs will be maintained for all
survey work, noting the date of the survey, equipment used, survey manager and
a record of all activities and observations.
Field logs will be retained for the duration of the Project and archived
on completion.
In-situ measured data will be digitally recorded from the
instruments and converted into Microsoft Excel format, or manually noted. Both disc copy and hard copy will be retained
for the file records. Any deviation from
the standard procedure will be noted in the log and the reason for the
deviation recorded. In addition, field
logs will contain notes of events or activities in the vicinity of the
monitoring location which might give rise to anomalous data being recorded.
3.7.2
Sampling
The sampling, collection, storage and
identification procedures are described in Section 3.6 of this Manual
and the Contractor will record all data from in situ testing and from
any analysis carried out on the boat in a Field Log. All samples will be identified with a unique
date/time/location/depth/sample-type code which will be attached to the sample
container or written in indelible ink directly on the container. In order to avoid contamination of the
samples, all containers will be new and unused and of analytical grade
quality. Sources of contamination will
be isolated from the working area (for example, vessel fuel and exhaust fames)
and any sample contaminated by local material (such as printed circuit boards)
will be discarded and the sampling repeated.
Low level metal analysis in seawater is easily contaminated through
inappropriate handling and sampling techniques.
Site staff involved in seawater sample collection intended for dissolved
metal analysis will ensure that they wear non-contaminating disposable gloves
if they have previously been operating or have handled metallic equipment.
3.7.3
Measurement Procedures
All in situ monitoring instruments will be
checked, calibrated and certified and subsequently re-calibrated at three
monthly intervals throughout all stages of the water quality monitoring, or as
required by the manufactures specification.
Certificate(s) of Calibration specifying the instrument will be attached
to the monitoring reports.
3.7.4
Transport of Samples
All samples transferred from one
sub-contractor to another will be accompanied by Chain of Custody (COC)
forms. Any missing or damaged samples
require notification to ET Leader following logging in the laboratory QA
system. The number of samples, the
parameters to be tested and the time of delivery should be clearly stated on
the COC forms to ensure that samples are analysed for the correct parameters
and suitable time is provided to the analytical laboratory for provision of
resources required in the analyses.
3.7.5
Laboratory Procedures
For details of the contaminants to be tested, the
methods to be used, the accreditation status of laboratory analytical methods,
instruments and procedures to be used, sample preparation information, method
detection limits (MDLs), QA/QC protocols and
turnaround times, contractor should refer to the previous monitoring programme
for the ESC CMPIV ([11])
([12])([13]).
The analytical techniques to be adopted for
this Project must conform to HOKLAS (or similar
overseas) accreditation.
3.7.6
Data Quality Objectives
Data Quality Objectives (DQOs)
have been developed in the previous monitoring programme for ESC CMPIV ([14])
([15])
to address precision,
accuracy and analyte recovery. The Contractor is recommended to follow the DQOs developed for data analysis.
Inorganic Analyses
Details of quality control specifications
for inorganic testing should be included in the updated EM&A Manual prior
to commencement of disposal activities.
Precision
Duplicates (1 in every 20 samples) will be
used to monitoring the precision of the analysis. Results should be flagged for reference when:
·
In
water samples, for metals with a concentration >4x MDL, the duplicate
results have more than a 15% RPD
·
For
all analytes with concentration <4x MDL, the
duplicate results will be reported as analysed and no bounds should be quoted
Accuracy
Standard and certified reference material
(CRM) will be used to monitor accuracy and precision within and between
batches: Results should be flagged for
reference if:
·
The
variation of the standard from its true value is more than ± 15% (for mercury: ± 20%).
Recovery
Post digest spikes will be used to determine
the recovery of determinants in complex sample matrices. Results should be rejected if:
·
Spike
recoveries are more than ± 25% from the theoretical recovery for
water samples. An exceptional case would
be if the sample concentration is greater than four times the spike value, the
spike may be disregarded.
4
Sediment Quality
4.1
Introduction
In accordance with the recommendations of the EIA for
the present Project, a monitoring programme examining sediment quality will be
instituted to verify the EIA predictions and ensure that there is no build-up
in contamination adjacent to the pits.
Sediment chemistry has long been an important component of monitoring
programmes at the East of Sha Chau
mud disposal complex. A comprehensive
list of Contaminants of Concern (COCs) has been used
since 1997, comprising eight heavy metals and one metalloid, polycyclic
aromatic hydrocarbons (PAHs), polychlorinated
biphenyls (PCBs), organochlorine pesticides (eg DDT) and Tributyltin
(TBT). These contaminants (which correspond
to the list of COCs in ETWBTC(W)
34/2002) in sediments should be measured in the present monitoring
programme and changes over time and distance should also be examined.
4.2
Objective
The main objective of this task is to determine if
there are any changes and/or trends in the concentrations of contaminants in
sediments adjacent to the pits caused by disposal activities at CMP IV and
V. This objective is most appropriately
addressed through two separate but intrinsically linked sub-tasks:
·
Pit Specific Monitoring of Sediment
Quality - conducted to
examine near field impacts of backfilling operations at CMP IV and V on the
spread of contaminants from the pits and to allow for rapid detection of any
adverse environmental impacts and, if necessary, changes to the operations
plan.
·
Cumulative Impact Monitoring of Sediment
Quality - conducted to
analyse the ambient conditions in the
4.3
Hypotheses
The impact hypothesis for this task is as follows:
There is no increase in sediment contaminant
concentrations over time at individual stations or a trend of increasing concentrations
with proximity to the active pit.
As a result of the separation of this programme into
two sub-tasks, two sets of null hypotheses should be tested:
Pit
Specific Monitoring of Sediment Quality
H0 There
is no increase in sediment contaminant concentration in the area adjacent to
the pits during contaminated mud disposal works.
Cumulative
Impact Monitoring of Sediment Quality
H0 There
is no increase in sediment contaminant concentration over time in the area of contaminated mud disposal activity.
H0 There
is no increase in sediment contaminant concentration with proximity to the active pits.
4.4
Sampling Design
The designs for assessing the impacts of
disposal of contaminated mud in the
active pits at CMP IV and V on the sediment chemistry of remote and
adjacent areas take into account the following factors:
·
The
null hypotheses being tested;
·
Background
levels of contaminants in the region;
·
Predictions
on sediment plume locations;
·
Spatial
variability in sediment chemistry;
·
Temporal
variability in sediment chemistry; and,
·
Expected
statistical treatment of the data.
As mentioned in Section
1. 2, this EM&A Manual is an evolving document that should be updated
to maintain its relevance as the Project progresses. This includes the relocation of monitoring
stations to best suit the requirements of the monitoring programme and to take
into account other work that is occurring in the direct vicinity of the active
facility.
4.4.1
Data Collection Parameters
The parameters that should be measured in sediments
collected during the two sub-tasks and the rationale for each are given
below. Some of the contaminants listed
are the "Contaminants of Concern" for which Lower and Upper Chemical Exceedance Limits (LCEL/UCEL) exist.
(a) Total
Organic Carbon (TOC) - an indicator of organic load and the impact on
bottom layer dissolved oxygen. TOC is an
important factor influencing the chemical partitioning and toxicity of
hydrophobic organic compounds such as PAHs, PCBs and
pesticides. High TOC often infers that
hydrophobic contaminants are less bioavailable;
(b) Inorganic Contaminants - metals and
metalloids present in the disposed sediments which may be bioaccumulated;
(c) Polycyclic Aromatic Hydrocarbons (PAH)
- a class of organic compounds some of which are persistent and
carcinogenic. These compounds may be bioaccumulated and stored in the fatty body tissues of
mammals;
(d) Total Polychlorinated Biphenyls (PCB) -
a class of persistent man-made chemicals which tend to bioaccumulate
through the food chain and can cause reproductive failure and cancer;
(e) Organochlorine Pesticides (DDE & DDT) -
contaminants which are persistent, highly lipophilic
(can be accumulated and stored in fat), have high bioaccumulation and biomagnification potential, and high toxicity to aquatic
organisms; and,
(f) Tributyltin (TBT) (in sediment and interstitial water)
- moderately persistent toxic compound found in marine sediments which may
be bioaccumulated and cause growth abnormalities and
reproductive failure.