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 HKSAR’s 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 Contractor’s general environmental awareness;
-
the
Contractor’s implementation of the recommendations in the EIA;
-
the
Contractor’s 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
Contractor’s 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 ± 2ºC.
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.
(g) Percentage of Silt/Clay (% < 63m)
– measured in Cumulative Impacts Monitoring only. Organic contaminants and metals bind more
readily to finer particles than coarser particles due to their larger surface
area and consequent larger number of binding sites;
4.4.2
Pit Specific Monitoring of Sediment
Quality
Pit specific monitoring of sediment quality will be
undertaken during backfilling activities.
For both CMP IV and V, sediment samples will be collected from two
stations in the active pit, two stations on the edge of the active pits and two
stations in close proximity to the pits.
For pit specific monitoring, parameters (a) to (g) in Section 4.4.1 will be analysed.
Sampling for CMP IV
For CMP IV the locations of stations are shown in Figure 4.1 and the coordinates are shown
Table 4.1. Sampling should be undertaken at each
station for three times per year. The
long-term review of environmental monitoring for contaminated mud pits ([16])
determined this sampling
frequency to be adequate to track potential changes in contaminant
concentrations of sediments.
Table 4.1 Coordinates
of Pit Specific Sediment Monitoring Stations for CMP IVc
|
Monitoring Stations |
Eastings |
Northings |
|
Near-Pit |
||
|
CNA |
811414 |
822982 |
|
CNB |
812734 |
821281 |
|
Pit-Edge |
||
|
CPA |
811607 |
822579 |
|
CPB |
812514 |
821393 |
|
Active-Pit |
||
|
NCA |
811849 |
822198 |
|
NCB |
812106 |
821608 |
Note: Coordinates are based on
Two replicate sampleswill be collected for each parameter from each
of the monitoring stations. The number
of replicate samples for CMP IV was determined from a power analyses which showed
this sampling was cost effective and sufficient
for the
environmental monitoring programme (1). Details on the Sampling
Programme for CMP IV are shown in Table C1 of Annex C.
Sampling for CMP V
Sediment samples will be collected on a
monthly basis from any of the six stations shown in Figure 4.2 and Table 4.2. Locations of the six sampling stations will
be dependent on the location of the active pit and will be adjusted
accordingly. For example when CMP Va is active, stations ESC-NNDA-B, ESC-NEDA-B and
ESC-NPDA-B will be monitored. Twelve
replicates of composite samples (i.e. 5 grab samples obtained using a cluster
grab) will be collected from each of the stations. Sampling frequency and the number of
replicates for CMP V will be reviewed and adjusted accordingly based on power
analyses in each Annual Report.
Table 4.2 Coordinates
of Pit Specific Sediment Monitoring Stations for CMP V
|
Monitoring Stations |
Eastings |
Northings |
|
CMP Va
active |
||
|
Near-Pit |
|
|
|
ESC-NNDA |
809547 |
822778 |
|
ESC-NNDB |
810636 |
821839 |
|
Pit-Edge |
|
|
|
ESC-NEDA |
809748 |
822606 |
|
ESC-NEDB |
810398 |
822031 |
|
Active-Pit |
|
|
|
ESC-NPDA |
809976 |
822414 |
|
ESC-NPDB |
810203 |
822206 |
|
CMP Vb
active |
|
|
|
Near-Pit |
|
|
|
ESC-NNCA |
810110 |
822994 |
|
ESC-NNCB |
811003 |
822185 |
|
Pit-Edge |
|
|
|
ESC-NECA |
810288 |
822825 |
|
ESC-NECB |
810792 |
822364 |
|
Active-Pit |
|
|
|
ESC-NPCA |
810477 |
822665 |
|
ESC-NPCB |
810652 |
822509 |
|
CMP Vc
active |
|
|
|
Near-Pit |
|
|
|
ESC-NNBA |
810831 |
823066 |
|
ESC-NNBB |
811780 |
822183 |
|
Pit-Edge |
|
|
|
ESC-NEBA |
810965 |
822939 |
|
ESC-NEBB |
811549 |
822378 |
|
Active-Pit |
|
|
|
ESC-NPBA |
811156 |
822726 |
|
ESC-NPBB |
811367 |
822544 |
|
CMP Vd
active |
|
|
|
Near-Pit |
|
|
|
ESC-NNAA |
811851 |
822535 |
|
ESC-NNAB |
812735 |
821751 |
|
Pit-Edge |
|
|
|
ESC-NEAA |
812046 |
822372 |
|
ESC-NEAB |
812553 |
821917 |
|
Active-Pit |
|
|
|
ESC-NPAA |
812196 |
822239 |
|
ESC-NPAB |
812371 |
822080 |
Note: Coordinates are based on
4.4.3
Cumulative Impacts Monitoring of Sediment
Quality
For both CMP IVc and V, sediment
samples should be collected from stations located in four discrete areas, with
two stations in each area. The areas
should be located at increasing distances from the disposal operations (ie. Near Field, Mid Field, Capped Pits
and Far Field). For CMP V,
sediment samples should also be collected from the Ma Wan station MW1. For cumulative impacts monitoring parameters
(a) to (g) in Section 4.4.1 will be
analysed.
Sampling for CMP IV
The locations of stations for CMP IV are shown in Figure 4.3 and the coordinates are
presented Table 4.3. Sampling should be undertaken at each
station twice per year. The long-term
review of environmental monitoring for contaminated mud pits ([17])
determined this sampling
frequency to be adequate to track potential changes in contaminant
concentrations of sediments.
Table 4.3 Coordinates
of Cumulative Impact Sediment Monitoring Stations for CMP IVc
|
Monitoring Stations |
Eastings |
Northings |
|
Near-field |
||
|
RNA |
811414 |
822982 |
|
RNB |
812734 |
821281 |
|
Mid-field |
||
|
RMA |
807351 |
823745 |
|
RMB |
814793 |
820405 |
|
Far-field |
||
|
RFA |
806207 |
827812 |
|
RFB |
806307 |
817693 |
|
Capped Pits |
||
|
RCA |
809024 |
821205 |
|
RCB |
809268 |
820942 |
Note: Coordinates are based on
Two replicate
samples for all organic contaminants and six replicate samples for metals and
PSD will be collected from
each of the monitoring stations. The number
of replicate samples for CMP IV was determined from a power analyses which
showed that this replication was adequate to monitor any potential impacts
while remaining cost effective (1).
Details on the Sampling Programme for CMP IV are shown in Table C1 of
Annex C.
Sampling for CMP V
Sediment samples should be collected four
times per year, twice during the dry season and twice during the wet season at
stations indicated on Figure
4.4 and the coordinates are
shown in Table 4.4. Twelve replicates of composite samples (i.e.
5 grab samples obtained using a cluster grab) will be collected from each
station. Sampling frequency and number
of replicates for CMP V will be reviewed and adjusted accordingly based on
power analyses in each Annual Report.
Table 4.4 Coordinates
of Cumulative Impact Sediment Monitoring Stations for CMP V
|
Monitoring Stations |
Eastings |
Northings |
|
Near-field |
||
|
ESC-RNA |
809547 |
822778 |
|
ESC-RNB |
810636 |
821839 |
|
Mid-field |
||
|
ESC-RMA |
807797 |
825010 |
|
ESC-RMB |
813278 |
820968 |
|
Far-field |
||
|
ESC-RFA |
806207 |
827812 |
|
ESC-RFB |
806307 |
817693 |
|
Capped Pits |
||
|
ESC-RCA |
809152 |
821238 |
|
ESC-RCB |
809313 |
820987 |
|
Ma Wan Station |
|
|
|
MW1 |
823603 |
823653 |
Note: Coordinates are based on
4.5
Statistical
Treatment of Data
4.5.1
Pit Specific Monitoring of Sediment
Quality
Observed differences in the levels of contaminants
should be tested using analysis of variance (ANOVA) with factors area and
station, followed by Student Newman Keuls (SNK)
multiple comparison procedures to isolate which treatments differ from
others.
For all of the analysis of variance techniques
performed during the monitoring programme, initial analyses should be performed
to ensure that the data complies with the specific assumptions of analysis of
variance. These assumptions state:
·
the
data within and among samples must be independent of each other;
·
the
variance within samples must be equal (tested through the use of tests such as Levene's median test); and,
·
the data among the samples must be normally distributed (tested through the
use of tests such as the Kolgomorov-Smirnov
test).
Should the data not comply with these
assumptions then the appropriate transformation should be applied to the data (eg, arc-sin for percentage data, log (x+1) for
abundance data, or rank transformation if necessary). If, after transformation, the data are still
non-compliant then non-parametric equivalents to ANOVA such as Kruskal-Wallis tests should be used.
4.5.2
Cumulative Impacts of Sediment Quality
The design of the monitoring programme
should allow nested analysis of variance techniques to be employed. These techniques will be used to analyse the
data at different spatial and temporal scales of replication. Statistical differences should be tested at
the following levels: between areas and between sampling times. An advantage of this sampling design is that
it removes the possibility of detecting differences simply due to inherent
variation over spatial scales in the active
area and thus facilitates clearer attribution to disposal operations. By replicating within each area, ie by sampling two stations in one area, any statistically
significant differences detected between areas are more likely to be due to
factors other than spatial variation (eg disposal
operations). This approach is now an
internationally recommended technique for use in monitoring programmes ([1]). Multidimensional scaling ordination
techniques will also be applied to the data, if deemed necessary.
4.6
Use of Data
Should significant increases be detected in the level
of contaminants in sediment samples, a review of the other monitoring
parameters should be undertaken. This
review will focus on sampling stations in the vicinity of the sediment quality
monitoring stations where increases are detected to see if these can be
attributed to contaminant migration from the active pits. Assessment of
the statistical significance of the data, confidence in the data and the
presence of supporting data from other components of the monitoring programme
should be jointly assessed. If
appropriate, changes to the operations plan should be considered.
4.7
Sampling
Procedure and Equipment
All samples should be collected by an experienced
sampling team, deployed on a survey boat equipped with fully calibrated
sampling equipment and precision navigational instruments. All vessel positioning should be accomplished
with a calibrated Differential Global Positioning System (DGPS), ensuring station
location accuracy to < ± 1 m (95% confidence), with sample
position automatically logged and mapped by the navigation computer. Where sample stations are located in close
proximity to the pit area, positioning should be further validated by use of an
echo sounder to detect whether the vessel is within the boundaries of the pit.
At each sampling station the top 5 cm of
seabed sediment should be collected using a 5-component cluster grab sampler
which collects surface sediments with a minimal disruption to the surface layer
and is designed to work effectively in soft sediment such as those found in the
area. The cluster grab should be
deployed once at each of the stations located within each sampling area (eg Pit-Edge). The
grabs can be customised and a fine mesh lid added, which ensures that the fine
fluid sediments on the surface of the seabed are retained in the sample. Utilisation of this cluster sampler allows a
large volume of sediment to be collected in a single deployment. Other similar samplers (eg
Petit-ponar) collect less sediment in each deployment
may have difficulty in collecting adequate samples in soft sediments, such as
those within the study area, thereby reducing efficiency and increasing
collection time. The five-cluster grab
should be collected and combined, and the sample, labelled, double-bagged and
stored in an ice chest cooled to a temperature of 4oC with ice
packs. The sediment sampler and all
other utensils should be rinsed with seawater after each sample has been
collected to avoid cross contamination between samples. On completion of the survey, all samples
should be promptly transported, in chilled containers, to the testing
laboratory for analysis.
4.8
QA/QC
A broad range of contaminants should be analysed in
sediment samples including metals, metalloids, PAHs, PCBs,
pesticides and Tributyltin in both sediment and
interstitial water. The method detection
limits should be consistent with previous monitoring programmes at East of Sha Chau. Other QA/QC procedures to be implemented for
marine sediment analyses include:
·
Laboratory blanks - an analyte
free matrix to which all reagents will be added in the same volumes or
proportions as used in the standard sample preparation to monitor contamination
introduced in the laboratory (organics and inorganics);
·
Batch duplicates - an intralaboratory
split sample randomly selected from the sample batch to monitor method
precision (intrabatch) in a given sample matrix (inorganics only);
·
Certified Reference Materials - analysis of a material with a known
concentration of contamination to determine the accuracy of results in a given
matrix (inorganics only);
·
Single Control Samples - a known, interference-free matrix
spiked with target analytes used to monitor
laboratory preparation techniques (organics only);
·
Duplicate Control Samples - multiple single control samples
designed to monitor preparation technique reproducibility (organics).
4.9
Data Quality
Objectives
Data Quality Objectives (DQOs) have been developed to address precision, accuracy
and analyte recovery.
4.9.1
Inorganic Analyses
Precision
Duplicates (1 in every 20 samples) should
be used to monitoring the precision of the analysis. Results should be flagged for reference when:
·
For
all analytes, except metals, with concentration
>4x Method Detection Limit (MDL), the duplicate results have more than a 20%
Relative Percentage Deviation (RPD)
·
In
water samples, for metals with a concentration >4x MDL, the duplicate
results have more than a 15% RPD
·
In
sediment and biota samples, for metals with a concentration >4x MDL, the
duplicate results have more than a 25% RPD
·
For
all analytes with concentration <4x MDL, the
duplicate results should 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 should be used to determined the recovery of determinants in complex sample
matrices. Results should be rejected if:
·
Spike
recoveries are more than ± 25% from the theoretical recovery for
waters, sediment and marine biota. An
exceptional case would be if the sample concentration is greater than four
times the spike value, the spike may be disregarded.
4.9.2
Organic Analyses
Samples should be analysed in lots of less
than 20. In order to measure the
laboratory performance within each batch of samples, a single control sample
(SCS), a duplicate control sample (DCS) and a method blank (MB) should be
processed concurrently with the samples.
A SCS or DCS consists of an interference free control matrix that is
spiked with a group of target compounds representative of the method analytes.
Method blanks, also known as reagent,
analytical, or preparation blanks, should be analysed to assess the level of
contamination that exist in the analytical system and which might lead to the
reporting of elevated concentration levels or false positive data. For organic analyses, the concentration of
target analytes in the blank must be below the
reporting limit for that analyte in order for the
blank to be considered acceptable.
Accuracy is
expressed as the average percent recovery for the SCS and precision is
expressed as the relative percent difference (RPD) for the DCS pair. For control limits that are not established due to insufficient
data sets, the QC Acceptance Criteria of US EPA Method 8080 and 8270A should be
used as a supplement. Once enough data
are collected, the in-house control limits should then be calculated.
The accuracy and precision data for SCS
and DCS should be evaluated against laboratory established control limits. QC results falling outside the control limits
should be automatically flagged. The
acceptance criterion is that 100 percent of the precision and accuracy values
must fall within the control limits. If
this criterion is not met, corrective action must be taken. This may include repeat sample analysis.
The average percent recovery of the SCS
should be compared to the limit set for each compound being monitored (Table
4.1). For DCS, an RPD of less than
20% is deemed to be acceptable in normal instances.
For multianalyte
organic tests, if greater than 20% of the accuracy or precision results for the
SCS/DCS are outside of the control limits, the data are considered suspect and
the samples associated with the unacceptable DCS are reprepared
and/or reanalysed.
Table 4.1 Quality
Control Acceptance Criteria for Organic Analyses
|
Target Analytes |
Percent Recovery Measured |
|
Naphthalene |
74 - 126 |
|
Acenaphthalene |
69 - 125 |
|
Acenaphthene |
73 - 119 |
|
Fluorene |
81 - 129 |
|
Phenanthrene |
74 - 131 |
|
Anthracene |
63 - 116 |
|
Fluoranthene |
73 - 134 |
|
Pyrene |
59 - 129 |
|
Benzo(a)anthracene |
77 - 136 |
|
Chrysene |
53 - 130 |
|
Benzo(a)pyrene |
51 - 103 |
|
Dibenzo(a,h)anthracene |
78 - 126 |
|
DDE |
73 - 121 |
|
DDT |
87 - 120 |
|
Total PCBs |
79 - 127 |
|
Tributyltin |
80 - 115 |
Result must be greater than zero
5
Sediment Toxicity
5.1
Introduction
The ecotoxicological
testing programme will feature a suite of tests that include three phylogenetically distinct species that interact with bedded
sediments in different ways.
Unacceptable impacts may have occurred if the levels of contaminants in
the sediments collected in the adjacent area of the active pits are shown to
have caused toxicity to marine fauna.
The findings of the sediment toxicity tests will be compared to the
results of the sediments chemistry.
5.2
Objective
The objective of this task is to determine
if there are any changes and/or trends caused by disposal activities in the
toxicity of sediments adjacent to the pits as a result of disposal activities.
5.3
Hypothesis
In accordance with the objectives of the
Study, the impact hypothesis for this task will be as follows:
There
is no increase in sediment toxicity over time at individual stations or a trend
of increasing toxicity with proximity to the pit.
The null hypothesis which should be
statistically tested is as follows:
H0 There
are no differences in the toxicity of sediments collected at stations adjacent
to the active pits when compared
with reference sediments.
5.4
Sampling Design
In order to determine whether contaminated
sediment placed in the active pits
represents an ecological risk to biota in areas adjacent to the mud pit, ecotoxicological evaluations will be performed on sediment
collected from these surrounding areas.
The toxicological testing programme should
feature a suite of tests that includes phylogenetically
distinct species which interact with sediments in different ways. The testing programme will include
whole-sediment, or solid-phase toxicity tests.
The following three international species should be tested:
·
Burrowing
amphipod (Leptocheirus plumulosus, Ampelisca abdita, Eohaustorius estuarius or
other equivalent species);
·
Burrowing
polychaete (Neanthes arenaceodentata or other equivalent species); and,
·
Free
swimming larvae of bivalves (Crassostrea gigas, Mytilus spp. or other equivalent species).
In addition, two of the following local
species should also be tested:
·
Amphipod
Melita longidactyla;
·
Polychaete Capitella capitata;
·
Juvenile
shrimp Metapenaeus ensis or Penaeus (Litopenaeus) vannamei; and,
·
Barnacle
larvae Balanus amphitrite.
The experimental designs for assessing the
impacts of disposal of contaminated mud in the East of Sha Chau
facility on the toxicity of sediments in remote and adjacent areas take
into account the following factors:
·
The
null hypotheses being tested;
·
Location
of other potential sources of contaminants in the North Lantau region, eg,
·
Predictions
taken from the EIA on sediment plume locations; and,
·
Expected
statistical treatment of the data.
Once
the pit is active (ie receiving contaminated mud),
sediment toxicity testing will be performed only when the level(s) of sediment
contaminant(s) in the Near-field station(s) exceed the LCELs
as measured by the Cumulative Impact
Monitoring of Sediment Quality. Sampling stations will be sampled not more
than twice per year (once in each of the wet and dry seasons).
5.4.1
Sampling for CMP IV
Sediment samples will be collected from
two treatment areas. The first treatment
is represented by samples taken from two stations in an area close to the active pits (Near-Field) and the
second treatment is represented by samples collected from stations in a
reference area (Far-Field). The
locations of stations are shown in Figure 5.1 and
the coordinates are presented in Table 5.1. At each of the stations, three replicate
composite grab samples will be taken and used for the sediment toxicity
tests.
Table 5.1 Sediment
Toxicity Testing Sampling Stations for CMP IVc
|
Station |
Eastings |
Northings |
|
Reference |
|
|
|
TRA |
806207 |
827812 |
|
TRB |
806307 |
817693 |
|
Near-Field |
|
|
|
TCA |
811414 |
822982 |
|
TCB |
812734 |
821281 |
Note:
Coordinates are based on
5.4.2
Sampling for CMP V
Sediment samples for CMP V should be
collected from two treatment areas as well as at the Ma Wan station. The first treatment area is represented by
samples taken from two stations in an area close to the active pits (Near-Field) and the second treatment area is
represented by samples collected from stations in a reference area
(Far-Field). The locations of stations
are shown in Figure 5.2 and the coordinates are presented in Table
5.2. Five replicates of
composite samples will be collected from each of the stations and used for the
sediment toxicity tests. Sampling
frequency and number of replicates for CMP V will be reviewed and adjusted
accordingly based on power analyses in each Annual
Report. In addition, locations of
sampling stations will be amended based on location of the active facility.
Table 5.2 Sediment
Toxicity Testing Sampling Stations for CMP V
|
Station |
Eastings |
Northings |
|
Reference |
|
|
|
ESC-TRA |
806207 |
827812 |
|
ESC-TRB |
806307 |
817693 |
|
Near-Field |
|
|
|
ESC-TDA |
809547 |
822778 |
|
ESC-TDB |
810636 |
821839 |
|
Ma Wan Station |
|
|
|
MW1 |
823603 |
823653 |
Note: Coordinates are based on
5.5
Statistical
Treatment of Data
Each of the toxicological tests will be
evaluated for statistically significant increases in toxicity. Statistically significant toxicity will be
determined by performing an analysis of variance (ANOVA) test that compares the
responses observed in the test treatments with those of the reference
treatments. At the end of the monitoring
programme changes in the toxicity of the sediments over time will be evaluated
through the use of two-factor ANOVA incorporating both spatial and temporal
scales of variation.
5.6
Use of Data
Once the data have been evaluated for
significance, it is important to identify potential causes of toxicity and the
biological significance of the observed effects. The cause of the observed effects needs to be
distinguished between 1) non-persistent contaminants, 2) persistent
contaminants, and 3) physical factors.
It is most important to determine if the cause of the toxicity is due to
persistent contaminants that are derived from the contaminated sediment placed
in the pits (eg metals, pesticides, PAHs, TBT), to non-persistent contaminants (eg sulfides, ammonia, salinity)
or to physical factors (eg grain size).
If the toxicity is due to persistent
contaminants that are associated with disposal operations, the operations plan
for the active pits may not be
effective enough at managing the containment of contaminated sediment to
acceptable levels and thus should be modified.
If the observed toxicity is due to non-persistent contaminants, the
effects may be due to the pit but they are transient. The toxicity of these types of contaminants
can be assimilated by the environment in relatively short time periods, and are
thus less harmful. If the effects are related
to physical factors, they are again of less concern and would not likely
require changes in the facility operations
plan.
As non-contaminant factors and physical
factors can confound toxicity test interpretation, the ET will monitor ammonia,
sulfides, interstitial salinity, and sediment-grain
size. Each of these factors has been
observed to elicit a toxic response in test organisms, however, they are not
factors related to persistent contaminants of concern. This information will be used to investigate
any observed toxicity responses and determine whether the response is due to
persistent contaminants or to more transient factors.
5.7
Data Collection
Parameters
The amphipod toxicity test with burrowing
amphipod (Leptocheirus plumulosus, Ampelisca abdita, Eohaustorius estuarius or
other equivalent species as agreed with
EPD/AFCD prior to conduct of the toxicity test) will evaluate survival
following a 10-day exposure to test sediment.
Procedures will follow those outlined in PSEP (1995) (1)
and/or USEPA (1994) ([18]), depending on the species used for the
test, and CEDD's Environmental Laboratory Guidance
Document (1996) (2). The
amphipod benthic test will be conducted as a static test and will be performed
with 175 ml of sediment and 800 ml of overlying seawater placed in a 1-L glass
jar. At test initiation, each of five
replicate test chambers will be seeded with 20 amphipods. Test chambers will be maintained at 20°C and will be checked daily throughout the
test to establish trends in sediment avoidance.
After the 10-day exposure, the benthic tests will be terminated by
sieving the sediments and enumerating the live and dead amphipods.
The test on Neanthes arenaceodentata (or a equivalent species as agreed with
EPD/AFCD prior to conduct of the toxicity test) will evaluate polychaete survival and growth following a 20-day exposure
to test sediment. Test methods will
follow those outlined in PSEP (1995) (3). The test will be conducted as a static test,
performed in 175 ml of sediment and 800 ml of overlying seawater in 1-L glass
jars. At test initiation, each of five
replicate test chambers will be seeded with five polychaetes. Test chambers will be maintained at 20°C and will be checked daily to record
mortality and sediment avoidance. To
promote growth, worms will be fed TetraMarin8 every third day
throughout the test. After 20 days, the N. arenaceodentata
test will be terminated by sieving each test chamber and enumerating both live
and dead organisms. Surviving polychaetes will be dried and weighed for each test
chamber. Average dry weight will be
compared to initial biomass to determine mean growth for each test
chamber.
The larval-development toxicity test will
be performed with fertilized bivalve embryos (Crassostrea gigas,
Mytilus galloprovincialis
or a equivalent species as agreed with EPD/AFCD prior to conduct of the
toxicity test) will evaluate larval survival and development following a
48 to 96-hour exposure to test sediments.
This procedure will follow those outlined in PSEP (1995) (1). This test will be conducted in 20 mg of test
sediment with 800 ml of seawater in 1-L glass jars. At test initiation, test jars will be seeded
with 20 to 40 embryos per ml. Test
chambers will be maintained at 16°C.
At termination, overlying water will be decanted and subsamples drawn
from the supernatant. Survival and
normal larval development will then be determined under an inverted compound
microscope.
In each of the sediment tests, a
sediment/seawater control (consisting of clean sediment for amphipod and polychaete or clean seawater for the bivalve larval test)
will be tested concurrently with the test sediments. The control treatment should be included to
determine the health of the test organisms.
Sediments collected from the reference stations will also be tested
concurrently with test sediments to provide a basis for statistical
comparison. For the larval tests,
grain-size controls will be tested concurrently with the test sediments to
discern any effects related to sediment grain size. Additionally, a water-only reference toxicant
test using cadmium (from CdCl2) or copper (from CuNO3)
will be conducted with each batch of test organisms. This reference-toxicant test provides a
measure of relative sensitivity for each group of test organisms. All toxicity tests will be completed and
reported within four months from collection of the samples.
5.8
Sampling
Procedure and Equipment
Procedures for sampling will be as for the
sediment chemistry for Sediment Quality Monitoring as detailed in Section
4.8 of this Manual. Shipments of the
sediments will be packaged in ice-boxes in order to maintain the sediments at a
constant temperature of 4oC and dispatched by express courier for
immediate testing.
5.9
QA/QC
To ensure the quality and integrity of the
ecotoxicological data and subsequent analyses, a
QA/QC control program will be followed that meets or exceeds the QA/QC program
outlined in Chapter 4 of CEDD's Environmental Laboratory Guidance Document (1996) (2). The QA/QC program for the facility ecotoxicological program is described below.
5.9.1
Sediment Handling and Chain-Of-Custody
Upon sample receipt, samples will be held
at 4° ± 2° C in the dark until required for
testing. Sediment holding times for
biological testing begin the day of sample collection and will be kept at a
minimum. The holding time for sediment
intended for biological testing will be eight weeks. Chain-of-custody forms will accompany each
batch of samples to track samples and to provide temperature data before and
after shipping.
5.9.2
Bioassay Seawater
Clean seawater for holding test organisms
will be sand-filtered seawater piped directly into the testing laboratory. Seawater used for test water and control
water should be additionally gravity-feed filtered through a 0.45 -mm filter before use for all test
species. Bioassay seawater should be
continually monitored for water quality and the presence of algal blooms.
5.9.3
Instrument Maintenance and Calibration
Procedures for calibration and maintenance
of water quality equipment will follow Measurement
Standards Laboratory (MSL) protocols.
All measuring and testing equipment used on this Project should be
traceable to the data collected and should be calibrated before use.
The pH meters used for obtaining water
quality data must be calibrated daily before use according to MSL-M-045,
Calibration and Use of pH Meters. The
calibration will be documented on the pH Meter Calibration Record sheet. Maintenance on pH meters will be performed
monthly. Maintenance should include
visual inspection, cleaning probes in 0.1 M HCl, and
cleaning any corroded contacts.
Refractometers used for obtaining water quality data
will be calibrated monthly using IAPO Standard Seawater according to MSL-M-048,
Calibration and Use of Refractometers. The calibration should be documented on the Refractometer Calibration Record sheet. Refractometers
should be inspected visually and cleaned monthly.
Digital thermometer calibrations will be
performed monthly by comparison to a certified mercury thermometer as specified
in MSL-M-047, Calibration and Use of Thermometers. The calibration will be documented on a
Thermometer Calibration Record.
Maintenance should include visual inspection and cleaning of salt and
corrosion from connectors and contacts.
Dissolved oxygen meters should be
calibrated daily before use according to MSL-M-046, Calibration and Use of
Dissolved Oxygen Meters. The calibration
should be documented on the Dissolved Oxygen Meter Calibration Record. Maintenance should be performed once monthly
and should include visual inspection, cleaning the probe, and replacing of
probe membrane.
The Fisher Accumet
1003 pH/selective ion electrode meter with ammonia electrode should be
maintained according to manufacturer’s instructions. The meter should be calibrated on each day of
use with three concentrations of NH4Cl standards bracketing the
expected test concentrations of ammonia.
The ammonia probe should be stored in 0.02 M NH4Cl when not
in use.
5.9.4
Data Review and Validation
In addition to QA/QC mentioned above, a
series of reviews by qualified laboratory personnel should be implemented to
ensure that the data generated for this Project meets the data quality
objectives. These reviews should include
the following:
·
Data
should be reviewed periodically by laboratory personnel to ensure that sample
testing activities are completely and adequately documented.
·
Sample
holding times, sample integrity, test animal handling and acclimation,
equipment calibration, water quality measurements, reference toxicity results,
observations, and control survival will be reviewed by qualified laboratory
personnel. The results of QC
measurements will be compared to pre-established criteria as a measure of data
acceptability.
·
A
final data audit by the Quality Assurance Officer will be performed prior to
submission of the data and report. This
audit will ensure that the data are accurate, traceable, defensible, and
complete, as compared to the Manual. The
audit procedure (MSL-Q-005, Quality Assurance Data Audits) is a statistical,
randomized check which involves comparing selected reported values to the
original data. This procedure is
designed to ensure a 95 percent chance of detecting whether one percent or more
reported values disagree with the original data.
The overall quality assurance objective
for this Project is to implement procedures that will ensure the collection of
representative data that is of acceptable and defensible quality. The data quality objectives for the ecotoxicological tests will be devised with reference to
the previous data quality objectives established for the previous monitoring
programmes for the East of Sha Chau
CMPs.
A negative control provides a measure of
test organism health. Negative control
treatment will be running concurrent to each toxicity test as a measure of the
test organism's health. For the amphipod
(eg Ampelisca sp ) and polychaete (eg Neanthes sp)
toxicity tests, the negative control should consist of clean, native sediment
that is to be collected from the test organism's natural habitat. For the bivalve larval test, the negative
control should consist of clean seawater.
Acceptable limits for the negative controls will be defined with
reference to the limits established for the East of Sha
Chau CMP monitoring programmes. If survival or normal development do not meet
the acceptability criteria, all data should be evaluated and the test may need
to be repeated.
Water quality measurements provide
documentation of environmental conditions within the test chambers during the
exposure. Temperature, dissolved oxygen,
pH, and salinity will be measured daily throughout the test. Conditions that are acceptable to maintain
the health of the test organisms will be defined with reference to the
acceptable conditions defined for the East of Sha Chau CMP monitoring programmes. If test conditions are outside the
acceptability criteria, the data will need to be qualified.
The positive control provides a relative
measure of test organism sensitivity.
For each of the bioassays for the active pits, a separate reference-toxicant
test should be performed with each batch of test organisms. The results of the reference-toxicant tests
will be compared with control charts generated by the testing laboratory for
that species and toxicant. Those results
within two standard deviations of the cumulative mean are considered to be
similar in sensitivity to previous test populations. For amphipods (eg A. abdita) the
reference-toxicant test will be performed with cadmium in the form of cadmium
chloride; for polychaetes (eg
N. arenaceodentata)
and bivalve larvae reference-toxicant tests will be performed with copper as
copper nitrate. If the test results are
outside the control limits, the data will need to be qualified.
6
Marine Biota
6.1
Introduction
The bioaccumulation of contaminants by prey organisms
and consequent biomagnification of contaminants up
the food chain has long been an issue of concern for the disposal of
contaminated mud at East of Sha Chau. Although the public at large may not appreciate
the technical details of a biomonitoring programme,
especially concerning mobile populations, they are well aware of the potential
for contaminated mud disposal to taint seafood products. In recognition of these issues, a
comprehensive biomonitoring programme which will
address public concerns about contamination of seafood in the area through use
of the data in a risk assessment framework should be undertaken for the
disposal activities at the active
pits.
6.2
Objective
As well as examining the influence of contaminated
sediment disposal on contaminant levels in demersal
fisheries resources, the impact of disposal on the abundance and structure of demersal fisheries should also be assessed. Consequently, there are two objectives for
this task:
·
Biomonitoring
of Contaminants - To
identify any increases in the concentrations of contaminants in tissues and
whole body burdens of demersal marine life adjacent
to and remote from the active pits.
·
Trawling, Sorting & Analysis - To assess the impact of contaminated
mud disposal at the active pits
on the fisheries resources of the
6.3
Hypothesis
In accordance with the predictions of the EIA and the
objectives for the Study, the impact hypothesis for this task is as follows:
There is no increase in
tissue or whole body contaminant concentration over time in selected target
species.
In order to reflect the dual workstreams
under this task, two sets of null hypotheses should be tested:
Biomonitoring
of Contaminants
H0 The
concentrations of contaminants in tissue and whole body samples of demersal marine life adjacent to the active pits are not greater than
contaminant concentrations from samples collected at stations remote from the active pits.
H0 The concentrations
of contaminants in tissue and whole body samples of demersal
marine life do not increase over time.
Trawling,
Sorting & Analysis
H0 There are
no differences in the composition or abundance of demersal
fisheries resources near to and remote from the active pits.
H0 There are
no differences in the composition or abundance of demersal
fisheries resources over time.
6.4
Sampling Design
6.4.1
Biomonitoring
of Contaminants
Samples for biomonitoring
of contaminants will be selected from trawl samples described in Section 6.4.2. Samples of the target species should be
collected twice per year (July/August in the wet season and January/February in
the dry seasons) specifically from six stations. The reference stations will comprise of two
stations located near Lung Kwu Chau
and two stations to the south west of the airport (Figures 6.1-2).
These reference stations are the same as those sampled in the ongoing
monitoring programme (Agreements No. CE
64/99 and CE 19/2004). The other two stations will be impact
stations, located on the edge of active pits.
However, in order to obtain sufficient tissue and whole body samples
from impact and reference stations, samples collected at different impact and
reference stations will be combined where necessary.
Due to concerns regarding the collection
of sufficient quantities of target species, catch from the first trawl survey
of each season (trawl for catch characterisation) should be retained in a
frozen state for joint processing with the biomonitoring
samples in the following month.
Five replicate tows (each with six nets)
should be conducted at each station and composite samples prepared from all
nets and tows at each station during each of the sampling events. Replicate data points should be obtained
whenever the abundance of target species allows laboratory analysis of more
than one tissue/whole body sample for each target species at each station. The design to be developed should address the
following key issues:
·
Rigour
of the dataset to allow for statistical testing of observed differences;
·
Data
required for the risk assessment;
·
Composite
samples to minimise the variance between fish and improve the reliability of detecting
any significant trends; and,
·
Analysing
replicate samples, whenever possible, to provide cost effective statistical
rigour.
Sampling for CMP
IV
For CMP IV, the locations of stations for
biota monitoring are shown in Figure 6.1 and
the coordinates are shown Table 6.1. Details on the Sampling
Programme for CMP IV are shown in Table C1 of Annex C. For CMP IV, a long term review of the monitoring
program showed that PAHs were rarely recorded above
detection limits and consequently these parameters will not be measured in the
monitoring programme for CMP IV.
Table 6.1 Demersal Trawl Sampling Station Coordinates (centre of the
transect) for CMP IVc
|
Station |
Eastings |
Northings |
|
Impact |
|
|
|
INA |
810808 |
822779 |
|
INB |
813561 |
820935 |
|
Reference |
|
|
|
TNA |
805353 |
828111 |
|
TNB |
806655 |
826440 |
|
TSA |
806115 |
815824 |
|
TSB |
804567 |
815308 |
Note: Coordinates are based on
Sampling for CMP V
The locations of biota monitoring stations
for CMP V are shown in Figure
6.2 and the coordinates
are shown Table 6.2. Details on the Sampling Programme for
CMP V are shown in Table C2 of Annex C.
Table 6.2 Demersal Trawl Sampling Station Coordinates (centre of the
transect) for CMP V
|
Station |
Eastings |
Northings |
|
Impact |
|
|
|
ESC-INA |
812651 |
822106 |
|
ESC-INB |
810730 |
823034 |
|
Reference
North |
|
|
|
TNA |
806220 |
827674 |
|
TNB |
806366 |
825248 |
|
Reference South |
|
|
|
TSA |
806366 |
816977 |
|
TSB |
805796 |
815951 |
Note: Coordinates are based on
6.4.2
Trawling, Sorting & Analysis
The design of the sampling programme
should encompasses the following key issues:
·
Temporal
variation in fisheries assemblages; and,
·
Spatial
variation of mobile assemblages of demersal fisheries
resources.
Samples should be collected for analysis
four times each year (twice in the dry season and twice in the wet season) to
account for temporal variation in the fisheries assemblages. The samples should be collected from 5
replicate trawls (each with 6 nets) undertaken along a transect at each of the
six stations, in which two stations are located at the impact area while four
stations are located at the two reference areas (Figure 6.1 and 6.2, for CMP IV and CMP V, respectively). Samples for biomonitoring
of contaminants will be selected from the trawl samples.
6.5
Statistical
Treatment of Data
6.5.1
Biomonitoring
of Contaminants
The data should be analysed using analysis of
variance (ANOVA) techniques to test for differences between the two sampling
sites (Impact and Reference). Once a
time series of data (sequential sampling events) has been gathered, differences
should be tested between sites and between the different sampling events to
examine any temporal trends in contaminant levels in the target species.
6.5.2
Trawling, Sorting & Analysis
Catch composition should be analysed using partially
nested analysis of variance (ANOVA) techniques to account for changes in
catches between and within sites in the
6.6
Use of Data
If significant increases are detected in the levels
of contaminants in fisheries resources in this programme it will indicate that
bioaccumulation is occurring. However, as demersal fisheries resources
are generally mobile (except burrowing species such as the gobies Trypauchen and Oxyurichthys), increases may not
necessarily be due to disposal at the disposal
facility. Other contaminant
sources such as discharges from the
6.7
Data Collection
Parameters
6.7.1
Biomonitoring
of Contaminants
The contaminants of concern for this project should be
measured separately, firstly in tissue samples (soft tissue) and secondly in
whole body samples obtained from the species list established for this
project. The species to be examined
should be chosen based on two criteria:
·
The
degree to which the organisms are exposed to contaminants in the sediments;
and,
·
The
position of the organisms in the food chain and the trophic
level of their predators (ie, humans or Indo-Pacific
Humpback Dolphin).
The species list (Table
6.3) has been devised with reference to the previous biomonitoring
programmes for the East of Sha Chau
CMP’s.
Comparing to the monitoring programme from February 2006 to April 2009,
the analysis of whole body samples of Cephalopods is suggested to be removed
from the present monitoring programme as according to Jefferson and Hung
(2004) ([19]), there is little evidence that
Indo-Pacific Humpback Dolphin consumed Cephalopods as a major prey item. Therefore, it is considered unnecessary to
analyze Cephalopods for the risk assessment of Indo-Pacific Humpback Dolphin
(please refer to Section 7 for
details of risk assessment).
Table 6.3 List
of Target Species for Tissue and Whole Body Analysis
|
Type |
Tissue
Analysis Target Species ([20])
|
Alternative
Species ([21])
|
Whole Body Analysis Target Species (1) |
Alternative Species (2) |
|
Prawn |
Metapenaeus ensis |
Metapenaeus joyneri |
Metapenaeus spp. |
Metapenaeopsis spp. |
|
|
Metapenaeus affinis |
Metapenaeopsis spp. |
|
|
|
Mantis Shrimp |
Oratosquilla oratoria |
Oratosquilla nepa |
Oratosquilla spp. |
|
|
|
|
Oratosquilla anomala |
|
|
|
Swimming Crab |
Charybdis cruciata |
Portunus sanguinolentus |
|
|
|
|
|
Scylla serrata |
|
|
|
|
|
Portunus pelagicus |
|
|
|
|
|
Portunus trituberculatus |
|
|
|
Flat Fish |
Cynoglossus macrolepidotus |
Cynoglossus trigrammus and Solea
ovata |
|
|
|
Burrowing Fish |
Trypauchen vagina |
Oxyurichthys tentacularis |
|
|
|
Demersal/Pelagic Fish |
Leiognathus brevirostris |
Collichthys lucida |
Leiognathus spp. |
|
|
|
|
|
Collichthys lucida |
Johnius
belengeri |
|
|
|
|
|
Other Sciaenidae |
|
|
|
|
Mugil spp. |
|
|
|
|
|
Thryssa spp. |
|
|
Gastropod |
Turritella terbra |
|
|
|
|
Non-Commercial Crab |
|
|
Charybdis spp. |
|
In the laboratory, each trawl sample should be sorted
for target species and target species selection should be based on the
abundance and potential sample mass available for each species captured. In preparing composite samples for analysis,
different species will not be mixed.
Each composite sample for laboratory analysis should consist of three or
more organisms, with priority given to larger individuals with no more than 2
fold difference in length. Length and
weight of all individual organisms represented by the composite sample will be
recorded and individuals for tissue sample analysis dissected with a sterilised
(with hexane) titanium knife and a composite sample prepared. Care should be taken not to cross
contaminate any tissue samples with gut contents. For fish, the axial muscle should be
extracted for analysis. For prawn/shrimp
and crab, abdominal and claw/leg muscle should be used, respectively. For gastropods, tissue samples should be
taken from the soft body tissue.
The analytical parameters for tissue and
whole body testing for both CMP IVc and CMP V are
given below:
·
Inorganic
Arsenic;
·
Cadmium;
·
Chromium;
·
Copper;
·
Lead;
·
Mercury
·
Nickel;
·
Silver;
·
Zinc
·
Total
Polychlorinated Biphenyls (PCBs);
·
Organochlorine Pesticides (DDE & DDT);
·
Tributyltin (TBT); and,
·
Moisture
content.
Polycyclic Aromatic Hydrocarbons (PAHs)
will be measured for CMP V only.
For CMP IVc, for each of
the target species a total of two replicates from each station should be
analyzed for each analytical parameter for tissue and whole body analysis,
respectively, except for Copper, Silver, Zinc and TBT in which five replicates
should be analyzed instead.
For CMP V, for each of the target species a total of
five replicates from each station should be analyzed for each analytical
parameter for tissue and whole body analysis, respectively.
Tissue Pooling and Preparation
In past monitoring programmes at CMP IV there have
been times when insufficient biota are collected in the trawl samples for
chemical analysis of contaminants. In
the event of a low catch, it is possible to pool samples using the procedures
shown in Table 6.4 and in the text below.
Table 6.4 Methodology for Pooling Samples to Obtain Sufficient
Tissue/Whole Body Samples for Analysis
|
Step |
Stations to Be Combined |
Decision Criteria (1) |
|
1 |
Impact (INA) + Impact (INB) = Impact Reference (TNA) + Reference (TNB) = Reference |
Proceed to step 2 unless tissue and whole body
samples are adequate for analysis |
|
2 |
Above + previous months Impact (INA) = Impact Above + Reference (TSA) + Reference (TSB) =
Reference |
Proceed to step 3 unless Proceed to step 2 unless
tissue and whole body samples are adequate for analysis |
|
3 |
Above + previous months Impact (INB) = Impact Above + previous months Reference (TNA) = Reference |
Proceed to step 4 unless Proceed to step 2 unless
tissue and whole body samples are adequate for analysis |
|
4 |
Above + previous months Reference (TSB) = Reference |
Proceed to step 5 unless Proceed to step 2 unless
tissue and whole body samples are adequate for analysis |
|
5 |
Above + Reference (TSA) and Reference (TSB) =
Reference |
N/A |
(1) Note that inter-seasonal pooling is not
permitted.
The pooling of Reference and Impact biota is not
permitted. Pooling biota from station in
the same area should only be done as a last measure.
Wherever possible, samples from the same station and
of the same species should be pooled together ie
pooling together Species X from TNA Trawl 1 January 2009 with TNA Trawl
2 January 2009 would be preferable to pooling samples from TNA and TNB, this
can sometimes be unavoidable due to low catch rates. Pooling of totally different taxa is not permitted, however,
similar taxa can sometimes be pooled when using
‘Alternative Species’ e.g Oratosquilla
nepa and Oratosquilla
anomala to form Oratosquilla
spp.
If insufficient material is obtained following
pooling then, material should be kept and used in ‘Alternative Species’ pooling
if they are of a similar group (e.g. if not enough Charybdis
cruciata are available after the pooling of
stations it is possible to pool with other Charybdis
sp.). Contaminant uptake is dependent on
the salinity of the water, which is seasonal.
Typically greater uptake occurs during the wet season when salinity is
lower than in the dry season ([22]).
For this reason, the pooling of samples between different seasons should
not be conducted.
6.7.2
Trawling, Sorting & Analysis
Catches from the trawl vessel should be processed to
record the abundance and biomass of individuals of commercial fisheries
resources as well as the number of species (or to the lowest possible taxonomic
level) present.
6.8
Sampling
Procedure and Equipment
Trawl sampling should be conducted by a shrimp
trawler equipped with a GPS system to ensure accurate positioning of each
trawl. Five replicate trawls, with six
nets deployed in each, should be conducted for 10 minutes at each station. If more than one of the six nets are retrieved in a damaged condition, the samples should be
rejected and the trawl repeated. To
ensure the maximum quality of the benthic trawl samples, several control
measures have been incorporated into the sampling programme, including:
·
no
more than three consecutive trawls should be conducted at a station and resampling should only occur after a minimum of two hours
has elapsed;
·
subsequent
trawls at each station should be shifted to avoid repetitive sampling over the
same area of seabed; and,
·
the first station sampled in each survey should be selected at random to
minimise the diurnal influences on catches.
Catches from all six nets in each trawl
should be combined to form one sample.
Each sample should be immediately washed and stored in sterilised (with
hexane) glass jars. All samples should
be chilled to 4oC and transported to the laboratory for further
sorting and analysis.
7
Human Health and Ecological Risk
Assessment
7.1
Introduction
The waters north of Lantau
have historically been important fishing grounds. These fishermen's catches comprise mainly
shrimps and crabs, as well as fish species of relatively low commercial value
such as pony fish, puffer fish and gobies (1). The North of Lantau
area also is recognized as the primary habitat of the Indo-Pacific Humpback
Dolphin (Sousa chinensis)
within
Disposal operations at the facility will
be designed to minimize the dispersion of contaminated sediments during
disposal and to prevent the long-term migration of contaminants through
placement of a clean sand and mud cap.
However, as losses of contaminated sediment will nevertheless occur during
placement, and as the area serves as habitat for marine species which may be
consumed by humans and/or the Indo-Pacific Humpback Dolphin, the risk of
adverse impacts must be addressed by the monitoring programme. Pathways of contaminant release to sensitive
receivers (ie humans and dolphins) include ingestion
of contaminated sediment, ingestion of dissolved and suspended contaminants in
water, and ingestion of organisms with contaminant residues.
Consequently, a risk assessment will be
performed on an annual basis to verify that no unacceptable risk are occurring
to either human health or marine mammals as a result of consuming prey species
from the waters in the vicinity of the pits of North Lantau. The details of the EM&A programme for
assessing hazard to health of humans and marine mammals are presented below.
7.2
Objective
The objective of the risk assessment
component of the monitoring programme is to determine whether disposal
operations at the active pits are posing an unacceptable risk to humans and
dolphins through consumption of seafood/marine prey species from the
7.3
Hypothesis
Given the above discussion of objectives,
the impact hypotheses for this component of the monitoring programme are
defined as follows:
For Human Health:
IH1: Risks to human health from consumption of
commercial species captured adjacent to the active pits are no greater than
risks associated with consumption of species remote from the active pits;
AND
IH2: Risks to human health from consumption of
commercial species captured adjacent to the active pits are
below the screening risk criterion (see Section 7.5).
For Dolphins:
IH1: Risks to dolphins from consumption of prey
species captured adjacent to the active pits are no greater than risks
associated with consumption of prey species remote from the active pits;
AND
IH2: Risks to dolphins from consumption of prey
species captured adjacent to the active pits are below the screening risk
criterion (see Section 7.5).
7.4
Sampling Design
Data required for the risk assessment
should consist of:
·
contaminant
concentrations in commercial/prey species collected from stations adjacent to
and remote from the active pits;
·
toxicology
data for humans and dolphins;
·
literature-derived
human consumption rates and patterns for seafood;
·
literature-derived
data on exposure of humans from other food groups;
·
literature-derived
data on contaminant levels in marine mammals;
·
data
collected by AFCD on contaminant levels in stranded Sousa chinensis carcasses; and,
·
existing natural history information for the Indo-Pacific
Humpback Dolphin and related species (eg diet
composition and feeding range).
The primary data input to the risk assessment should
derive from the bi-annual trawl (ie tissue samples
for human populations and whole body samples for dolphins) monitoring
events. The risk assessment will be
performed on an annual basis.
7.5
Use of Data
The risk assessment will follow the
guidelines of the US Environmental Protection Agency (1)(2)
and will incorporate a four-step approach involving problem formulation, estimation
of exposure, characterization of ecological or human health effects (injury),
and risk characterization. Each of these
steps is described below with reference to how each applies to both human
health and ecological risk assessment.
Problem
Formulation: Also known as hazard definition (3),
the problem formulation will describe the sensitive populations (eg the general Hong Kong population, subsistence fishermen,
the Indo-Pacific Humpback Dolphin) and identify biological effects of concern
potentially associated with the CMP operations at the active facility. Identification of these effects should
include a discussion of contaminants of concern, measurement endpoints and a
conceptual model embodying the mechanisms of contaminant migration.
Estimation
of Exposure: The purpose of the exposure estimation is to
determine the intake of each contaminant of concern by potentially exposed
individuals. This step will consider the
various routes of contaminant release and their migration from the site to
sensitive receivers. Factors such as
fate and transport processes, the concentrations in the ambient environment,
and the maximum short-term or average lifetime doses should be assessed.
For human populations exposure factors
presented in previous reports (1) (2) will be critically evaluated
to determine if further modification is necessary. These factors, which include amounts of
seafood consumed, origin of seafood products, and methods of preparation (eg raw versus cooked, whole body vs
tissue only) will be evaluated for the general population and any sensitive
subpopulations (eg subsistence fishermen fishing in
the East of Sha Chau
area).
Characterization
of Effects: The effects assessment is designed to quantify
the relationship between the degree of exposure to a substance and the extent
of toxic injury or disease. This step in
the assessment will use data derived from dose response studies on laboratory
animals or, less frequently, on exposed human populations and clinical
trials. For non-carcinogenic substances,
once the relationship between doses and responses is established, a threshold
which represents the highest contaminant concentration that is not expected to
result in an adverse effect, ie the reference dose (RfD) or a No Observed Adverse
Effect Level (NOAEL) can be established.
This threshold will then compare to the dose derived from the exposure
assessment above to produce the risk characterization.
For humans, dose-response relationships
must be considered separately for carcinogens and non-carcinogens. When dealing with carcinogens, a cancer
potency factor (CPF) or Slope Factor (SF) for each contaminant of concern will
be used. For non-carcinogens, the NOAEL
or LOAEL (lowest observed adverse effect level) will be used as the threshold
value. Data on CPFs
and NOAEL/LOAEL values are available through the U.S. EPA's
IRIS (Integrated Risk Information System) and HEAST (Health Effects Assessment
Summary Tables) databases. The
relationship between contaminant concentrations in toothed cetacean tissues and
the concentrations in their prey items will be assessed in this programme.
Risk
Characterization: The risk characterization will integrate
the results of the exposure and effects assessments to estimate the risks and
consequences of contaminant exposures.
In this step, the estimated exposure should be divided by the threshold
value to obtain a Hazard Quotient (HQ).
Generally HQ values below 1 are considered to represent a very low risk
of adverse effects, whereas HQ values above 10 indicate a moderate to high
level of risk.
For human populations, the general
approach to evaluating HQs can be applied to this Project. However, the human health risk
characterization produced for this Project should be updated through the use of
continually collected tissue and other environmental monitoring data to reflect
current conditions. This Study's human
health risk assessment will improve the robustness of previous studies through
a careful reconsideration of all exposure and effects parameters, with
particular focus on background doses and seafood consumption patterns.
8
Benthic Recolonisation
8.1
Introduction
The EIAs
conducted for CMP IV and V have indicated that benthic fauna are expected to recolonise the pits following capping with uncontaminated
mud. It is expected that recolonisation of the natural benthic assemblage will occur
and eventually the benthic assemblage will resemble that of the surrounding
areas. Recolonisation
may be achieved by larval recruitment, influx of juveniles or adults carried in
water currents, or through the active swimming or crawling of individuals. However, other natural (eg
storm events, hypoxia, salinity fluctuations) or anthropogenic (eg pollution, dredging activities and fisheries operations)
activities may hinder recolonisation of capped
pits. As a result, the factors
contributing to the composition of the benthic assemblage may be difficult to
determine. It is also important for any recolonisation studies to be aware of any cap maintenance
(or "topping up") activities which may also impact the resident
benthic assemblages.
In order to verify the recolonisation
of marine biota on the capped pits, a benthic recolonisation
programme is recommended. The full
details of the EM&A programme for benthic recolonisation
are presented in the following sections.
8.2
Objective
The objective for this component of the
Study is to monitor and report on the benthic recolonisation
of the capped pits including the previous ones and specifically to determine
the difference in infauna between the capped pits and
adjacent sites.
8.3
Hypothesis
The impact hypothesis for this task is as
follows:
Recolonisation is occurring at the capped
pits such that assemblages at the capped pits become more similar to reference
assemblages as time since capping increases.
The null hypothesis to be tested for this
work component is as follows:
H0 There
is no difference in the structure of benthic infaunal
assemblages found at the capped pits at the active facility and adjacent
reference areas.
H0 Similarity
of assemblage structures between impact and reference stations does not change
over time.
8.4
Sampling Design
The sampling design of this task involves
two treatments: capped pits and reference areas. The capped pit treatment will involve collection
of samples from the capped mud pits at the active facility. The second treatment will involve sampling at
different reference sites, which are chosen to improve the balanced nature of
the design. Using multiple controls is
an effective way of ensuring that the extremely variable nature of
The benthic sediment samples collected
during this task will be analysed for the following parameters:
·
Percentage
of silt/clay in the sediments;
·
Faunal Abundance;
·
Faunal Biomass;
·
Species
Composition; and,
·
Trophic Structure
Sampling for CMP IIId
For CMP IIId the
locations of impact and reference stations are shown in Figure 8.1 and the coordinates are shown
in Table 8.1. Three replicate samples will be
collected from each station twice per year, once in the dry season and once
during the wet season. Sampling will be
undertaken as detailed in the Sampling
Programme in Table C1 of Annex C.
Table 8.1 Coordinates
of Benthic Monitoring Stations for CMP IIId
|
Station |
Easting |
Northing |
|
Reference |
|
|
|
RBA |
806252 |
821271 |
|
RBB |
807405 |
821963 |
|
RBC |
807232 |
821165 |
|
Capped Pit |
|
|
|
CPA |
809144 |
821271 |
|
CPB |
809009 |
820963 |
|
CPC |
809336 |
820992 |
Note: Coordinates are based on
Sampling for CMP IV
The locations of impact and reference
stations for CMP IV are shown in Figure 8.2 and
the coordinates are shown Table 8.2. For standardisation
purposes, the reference stations are at the same locations as CMP IIId ([23])
(refer to Figure 8.1). Samples should be collected twice per year,
once in the dry season, once during the wet season. Twelve replicate samples will be collected from each of the
monitoring stations. Sampling will be
undertaken after capping completed at CMP IV as detailed in the Sampling Programme in Table C2 of Annex C. Sampling frequency and number of
replicates for CMP IV will be reviewed and adjusted accordingly based on power
analyses in each Annual Review Report.
Sampling for CMP V
The sampling design for benthic recolonisation study of CMP V will be incorporated into
this Manual and commenced once capping at CMP V is completed.
Table 8.2 Coordinates
of Benthic Monitoring Stations for CMP IV
|
Station |
Easting |
Northing |
|
Reference |
|
|
|
RBA |
806399 |
821682 |
|
RBB |
808206 |
822708 |
|
RBC |
806171 |
819354 |
|
Capped Pit |
|
|
|
CPA |
809899 |
821634 |
|
CPB |
811006 |
821780 |
|
CPC |
811788 |
821878 |
Note: Coordinates are based on
8.5
Statistical
Treatment of Data
The data collected during the monitoring
programme will be analysed using two different but complementary approaches as
detailed below.
8.5.1
Univariate
Analyses
ANOVA
& MANOVA: Simple, univariate
measures will be tested using an Analysis of Variance (ANOVA), and multivariate
measures of community structure will be tested using the Multiple Analysis of
Variance (MANOVA). Both ANOVA and MANOVA
test the same null hypothesis using similar methods. The method is essentially a comparison of the
variability within a site to the variability between sites. If the ratio of these two variances (that is,
the between‑group‑variance over the within‑group‑variance)
is large enough, then any differences observed are due to true differences that
exist between the groups and not just to random
variation. ANOVA and MANOVA tests are
based on several assumptions related to the underlying distribution of the data
being analysed (ie normality, homogeneity of
variances). If the data deviate
significantly from these assumptions, then these tests are considered to be
inappropriate. If this situation arises,
alternative procedures (ie parametric tests with rank
transformed data or nonparametric analogues such as Kruskal
Wallis) which address similar hypotheses but do not require such stringent
assumptions will be adopted. Observed
differences between the sites and/or areas will be tested using multiple
comparison procedures such as the Student Newman Keuls
(SNK) or Tukey test.
8.5.2
Multivariate Analyses
Multi
Dimensional Scaling (MDS): Multi dimensional scaling (MDS) will also be
used to depict the similarities between stations based on their benthic
assemblages. MDS is a method for creating
a low dimensional picture of the relationships between stations in a complex,
multi dimensional problem. The
Bray-Curtis distance metric will be used for both the clustering techniques and
the MDS. The dendrogram
from the cluster analysis and the MDS ordination plot will provide
complementary views of the same similarity information. The data for MDS and cluster analyses should
be standardised prior to analysis, to ensure that bias resulting from including
data in different forms (eg percent data for silt
clay composition, numerical data for abundances and biomass data in mg) does
not occur.
8.6
Use of Data
The detailed statistical analyses
described above will be used to comprehensively explore the benthic assemblage
patterns in the area of the active pits.
This exploration should lead to conclusions regarding the effectiveness
of the cap material in promoting post-dredging benthic assemblages.
8.6.1
Sampling Procedure and Equipment
The sampling team and vessel will be deployed
and accurate positioning attained as described in Section 4. The vessel will be equipped with adequate
fixed sieve stations to facilitate rapid processing of samples and ensure the
maximum number of samples are collected in each
survey. At each of the designated
benthic sampling stations, seafloor sampling will be carried out with a
modified Van Veen grab sampler (dimensions 30 cm H 30
cm H 15 cm) or similar instrument approved by EPD/AFCD. One subsample of approximately 1 kg sediment
will be collected from each sample for analysis of particle size. The remaining sediment from each sample will
be used for sorting. Samples will be
labelled and sieved through a 1 mm and 0.5 mm sieve and all residues and
organisms retained, double-bagged and preserved in 4% buffered formalin in
seawater. A vital stain (eg Rose bengal)
will be added to distinguish organic materials and organisms from other
non-living residues. The grab and
utensils will be washed thoroughly with seawater after each deployment to avoid
cross-contamination between samples. On
completion of the survey all samples will be transferred to the laboratory for
sorting and identification. All sediment
sieving will be conducted by qualified marine scientists who will oversee and
coordinate all field operations.
8.7
Laboratory
Procedures
Upon arrival at the laboratory, all
benthic samples should be re-inventoried and checked against chain-of-custody
forms. Sample rescreening should be
performed after the samples have been held in formalin for a minimum of 24
hours to ensure adequate fixation of the organisms. Individual samples from the 500 mm and 1 mm2 mesh sieves will be
gently rinsed with fresh water into a 250 mm sieve to remove the formalin from the
sediments. Sieves will be partially filled
while rinsing a specific sample to maximize washing efficiency and prevent loss
of material. All material retained on
the 250mm sieve is placed in small fractions into a labelled petri dish and preserved with 70% ethanol. The material is lightly agitated to ensure
complete mixing of the alcohol with the sediments. The sediment is then sorted to remove all
animals and fragments. Original labels
will remain with the rescreened sample material.
Standard and accepted techniques will be
used for sorting organisms from the sediments (1). Small fractions of a sample will be placed in
a petri dish under a 10-power magnification
dissecting microscope. The petri dish will be scanned systematically and all animals
and fragments removed using forceps.
Each petri dish will be sorted at least twice
to ensure removal of all animals.
Organisms representing major taxonomic groups including Polychaeta, Arthropoda, Mollusca, and miscellaneous taxa
will be sorted into separate, labelled vials containing 70 percent ethanol. All sorted samples will be systematically
checked to ensure compliance with QA/QC program requirements before proceeding
to the taxonomic identification, enumeration, and biomass determination phases
of the analysis.
Taxonomic identifications will be
performed by regional taxonomic experts using stereo dissecting and high-power
compound microscopes, to the family level except for dominants, which will be
identified, where possible, to species.
The careful sampling procedure employed in the Study will minimise
fragmentation of organisms, however should breakage of soft-bodied organisms occur, only anterior portions of organism fragments will be
counted. All fragments will be retained
and weighed during biomass determinations, described below. Rare or questionable taxa
will be compared against reference collection specimens for confirmation and
consistency of identification. The
nomenclature used in all reference collections referred to in this study should
be cross checked and differences or discrepancies should be noted. Biomass determinations will be made by taking
the blotted wet mass of each taxonomic fraction.
8.8
Benthic
Macro-Infauna and Taxonomic Identification
Sorting QA/QC will be performed using
25-power magnification by someone other than the original sorter. Twenty percent of each sorted sample should
be resorted to ensure 95 percent sorting efficiency. A sample passes QA/QC if the number of
organisms found during the QA/QC check does not represent more than 5 percent
of the total number of organisms found in the entire sample. If the number of organisms found is greater
than 5 percent of the total number, the entire sample will be resorted. Any samples where the identification of taxa is questionable will be sent out for independent reidentification by a qualified regional expert. Reference collections developed during
previous seabed and benthic studies in
9
Impacts of Major Storms
9.1
Introduction
Based on the previous experience with the development
and approval for CMPs at East of Sha
Chau for use as a confined disposal facility for
contaminated mud, monitoring of the dispersion of uncapped sediments during
major storm events, such as typhoons of signal 8 or higher, is an important
objective of the study. It is therefore
considered necessary to include this post-storm monitoring as part of the
EM&A programme for the mud disposal facility.
9.2
Sampling Design
The post-storm monitoring programme will mobilise
within one week of a major storm event (Typhoon Signal Number 8 or above) in
order to determine whether the pits retain disposed sediments during storms and
whether there are any detectable changes in sediment quality adjacent to the
pits. Sediment samples will be collected
within one week of a major storm at stations of the cumulative impact sediment
quality monitoring programme (Section
4.4.3). Locations of the sampling
stations are depended on the location of the active pit; when CMP IVc is active for disposal operations sediment samples will
be taken from sampling stations illustrated in Figure 4.2
while stations shown in Figure 4.4 will be
monitored if CMP V is the active pit.
Only inorganic contaminants and particle size distribution (organic
contaminants are not measured as inorganics can
provide a more cost-effective indicator of any sediment quality change) will be
analysed in the storm assessment.
The field, laboratory and QA/QC procedures
for sediment sample collection after major storm events will be identical to
those used for the Cumulative Impact Sediment Quality Monitoring Programme (Section 4).
10
Reporting
10.1
General
Reports will be provided in both hard copy
and electronic version upon agreeing the format with EPD. This would enable a transition from a
paper/historic and reactive approach to an electronic/real time proactive
approach. All the monitoring data should
also be submitted on CD / DVD.
10.2
Reports
The following documents
will be submitted to CEDD for the EM&A programme:
·
Inception Report;
·
Environmental Monitoring and Audit Manual;
·
Operations Manual;
·
Tender Documents;
·
Contract Documents;
·
Reports on Dredging and Capping Operations;
·
Monthly Progress Reports;
·
Quarterly EM&A Reports;
·
Annual Review Report;
·
Annual Risk Assessment Report;
·
Draft Final Report;
·
Executive Summary Report; and
·
Final Report.
Monthly
Progress Reports will be
required for the duration of the programme period and will be submitted to CEDD
by the 10th working day of each month. Each report will contain:
·
A list of the activities, tests, analyses and
assessments performed in the month according to that detailed in the Monitoring
and Audit Manual for the purpose of reporting any significant findings resulting
from monitoring and audit activities;
·
a list of outstanding activities, tests, analyses
and assessments as well as the schedule for completing these outstanding items;
and,
·
a list of
previously outstanding
activities, tests, analyses and assessments that are completed in the month.
Quarterly EM&A Reports will be required for the duration of the
programme period and will be submitted within 30 days from the end of every
quarterly monitoring period. Each report
will:
·
confirm
that all activities, tests, analyses, assessments etc. have been carried out as
stated in this EM&A Manual;
·
report
on the auditor's findings on the field events and laboratory tests and
analysis;
·
report on any trends resulting from disposal, dredging and capping
activities at the active facility.
An Annual Review Report will
be submitted within 60 days from the end of every yearly monitoring
period. Each report will:
·
make
a clear statement on the acceptability of environmental impacts by reference to
the impact hypotheses;
·
state
how successful the monitoring programme has been in addressing the objectives
of the Assignment;
·
make
recommendations for revisions to the monitoring programme and disposal
operation, as necessary, to ensure that the objectives are fully met in a cost
effective manner; and
·
summarise the monitoring results to illustrate whether any
change or trend resulting from the disposal, dredging and capping activities is
detected or not.
A Risk Assessment Report will be prepared within 60 days from the
end of every yearly monitoring period.
Each report will address the risk to the human health and dolphin of
eating seafood taken in the marine area around
A Draft Final Report will be prepared within
90 days from the end of the monitoring period for this Assignment. It will address how each objective of the
assignment has been met and should will included a
final version of the EM&A Manual as an appendix.
A Final Report will be prepared within 3 weeks after the agreed
revisions on the Draft Final Report.
An English and Chinese Executive Summary Report
will be prepared within 3 weeks of receipt of comments on the Draft Final
Report. It should highlight any issues
of concern and the acceptability of the operations at the active pits.