7.1.1 Relevant legislation and guidelines for the disposal of contaminated sediments at marine disposal sites are listed below.
·
Annexes
7 and 15 of the TM-EIAO, Criteria and Guidelines for Evaluating and Assessing
Waster Management Implications;
·
Dumping at Sea Ordinance (DASO) (Cap.466);
·
Environment, Transport and Works Bureau
Technical Circular (Works) No. 34/2002 “Management
of Dredged/Excavated Sediment” (ETWB TC(W) No. 34/2002); and
·
Works Bureau Technical Circular (WBTC) No.
12/2000 Fill Management.
7.1.2 The DASO is the principal statutory legislation to control dumping of sediment at sea. It safeguards the water quality and ecology of Hong Kong waters.
7.1.3 ETWB TC(W) No. 34/2002 sets out the procedure for seeking approval to dredge/excavate sediment and the management framework for marine disposal of such sediment. It covers the approval of dredging/excavation proposals and marine disposal of dredged/excavated sediment. ETWB TC(W) No. 34/2002 also provides guidelines for the classification of sediment based on their contaminant levels. Sediment quality criteria for classification include:
·
Metals (cadmium,
chromium, copper, mercury, nickel, lead, silver and zinc);
·
Metalloid
(arsenic); and
·
Organic micro-pollutants
(PAHs, PCBs and TBT).
7.1.4 Based on the criteria, sediment is classified into Category L (low contamination level), Category M (medium contamination level) or Category H (high contamination level).
7.1.5 This technical circular also stipulates a three-tier screening for sediment assessment for determining the disposal options. Details of this three-tier approach are given in Section 7.2.3 – 7.2.5.
7.2
Methodology
for Sediment Quality Assessment
7.2.1 The management framework of dredged/excavated sediment in Hong Kong is implemented under a three-tiered approach as illustrated in Appendix 7.1 in accordance with the ETWBTC (Works) No. 34/2002. Sediment will be classified as 3 categories as follows:
Category L Sediment
with all contaminant levels not exceeding the Lower Chemical Exceedance Level
(LCEL). The material must be dredged, transported and disposed of in a manner
that minimises the loss of contaminants either into solution or by suspension.
Category M Sediment
with any one or more contaminant levels exceeding the Lower Chemical Exceedance
Level (LCEL) and none exceeding the Upper Chemical Exceedance Level (UCEL). The
material must be dredged and transported with care, and must be effectively isolated
from the environment upon final disposal unless appropriate biological tests
demonstrate that the material will not adversely affect the marine environment.
Category H Sediment with any one or more contaminant
levels exceeding the Upper Chemical Exceedance Level (UCEL). The material must
be dredged and transported with great care, and must be effectively isolated
from the environment upon final disposal.
7.2.2 Table 7.1 summarises the guidelines for the assessment, sampling, testing and classification of sediment. Detailed description of the three-tier approach stipulated in the ETWB TC(W) No. 34/2002 is described below.
Table
7.1
Test endpoints and decision criteria for Tier III biological screening under
ETWBTC (Works) No. 34/2002
|
Contaminants |
Lower
Chemical Exceedance Level (LCEL) |
Upper
Chemical Exceedance Level (UCEL) |
|
Heavy Metal (mg/kg dry weight) |
||
|
Cadmium
(Cd) |
1.5 |
4 |
|
Chromium
(Cr) |
80 |
160 |
|
Copper (Cu) |
65 |
110 |
|
Mercury
(Hg) |
0.5 |
1 |
|
Nickel (Ni)(1) |
40 |
40 |
|
Lead (Pb) |
75 |
110 |
|
Silver (Ag) |
1 |
2 |
|
Zinc (Zn) |
200 |
270 |
|
Metalloid (mg/kg dry weight) |
||
|
Arsenic |
12 |
42 |
|
Organic-PAHs (µg/kg dry weight) |
||
|
PAHs (Low
Molecular Weight) |
550 |
3160 |
|
PAHs (High
Molecular Weight) |
1700 |
9600 |
|
Organic-non-PAHs (µg/kg dry weight) |
||
|
Total PCBs |
23 |
180 |
|
Organometallics (µg-TBT L-1 in
interstitial water) |
||
|
Tributyltin(1) |
0.15 |
0.15 |
Note:
(1)
The contaminant level is considered to have exceeded the UCEL if it is
greater than the value shown.
Tier I Screening
7.2.3
Tier I screening is a
desktop screening process to review the available information and determine
whether the sediment of concern belongs to Category L material suitable for
open sea disposal. If there is insufficient information to arrive at such
a conclusion, Tier II chemical screening shall be proceeded directly.
Tier II Screening
7.2.4 Tier II screening is a chemical screening process to categorise sediment based on its chemical contaminant levels and to determine whether the sediment is suitable for open sea disposal without further testing. Upon Type II screening, the sediment shall be classified as Category L, M or H material. Category L material is suitable for Type 1 disposal - Open Sea Disposal, but Categories M and H will require Tier III screening to further determine the disposal option.
Tier III Screening
7.2.5 Tier III screening is a biological screening process for further analysis of Category M and certain Category H sediment (contaminant levels exceed 10 times Lower Chemical Exceedance Level). Sediment classified as Category M shall be subjected to the following three toxicity tests:
·
A 10-day burrowing amphipod toxicity test;
·
A 20-day burrowing polychaete toxicity test; and
·
A 48-96 hour larvae (bivalve or echinoderm)
toxicity test.
7.2.6
Table
7.2 summarizes the details of
the test endpoints and failure criteria of the three toxicity tests.
Sediment classified as Category H and with one or more contaminant levels
exceeding 10 times LCEL shall also be subjected to the above three toxicity tests
but in a diluted manner (dilution test). If the Category M material
passes the biological test (i.e. Mp material), Type 1 disposal - Open Sea
Disposal (Dedicated Sites) is required. In case of failure of biological
test on Category M material (i.e. Mf material), Type 2 disposal - Confined
Marine Disposal shall be required. For Category H material which passes
the biological test (i.e. Hp material), Type 2 disposal - Confined Marine
Disposal shall be required. However, Type 3 disposal - Special Treatment/Disposal
shall be required for Category H material if biological test is failed (i.e. Hf
material).
Table 7.2 EPD sediment quality data between 2005 and
2009 at Junk Bay
|
Toxicity Test |
Endpoints Measured |
Test Methods |
Failure Criteria |
|
10-day amphipod |
Survival |
USEPA Standard Methods for Assessing the Toxicity of
Sediment-associated Contaminants with Estuarine and Marine Amphipods |
Mean survival in test sediment is significantly different (p≤0.05)(1) from
mean survival in reference sediment and mean survival in test sediment
<80% of mean survival in reference sediment. |
|
20-day polychaete worm |
Dry Weight(2) |
PSEP Standard Recommended Guidelines for Conducting Laboratory
Bioassays on the Pudget Sound Sediments – Juvenile Polychaete Sediment
Bioassay, 1995 |
Mean dry weight in test sediment is significantly different (p≤0.05)(1) from
mean dry weight in reference sediment and mean dry weight in test sediment
<90% of mean dry weight in reference sediment. |
|
48-96 hour larvae (bivalve or echinoderm) |
Normality Survival(3) |
PSEP Standard Recommended Guidelines for Conducting Laboratory
Bioassays on the Pudget Sound Sediments – Bivalve Larvae Sediment Bioassay,
1995 |
Mean normality survival in test sediment is significantly different (p≤0.05)(1) from
mean normality survival in reference sediment and mean normality survival in
test sediment <80% of mean normality survival in reference sediment |
Note:
(1)
Statistically significant differences should be determined using
appropriate two-sample comparisons (e.g. t-tests) at a probability of
p≤0.05.
(2)
Dry weight means total dry weight after deducting dead and missing
worms.
(3)
Normality survival integrates the normality and survival end points, and measures survival of only the normal larvae
relative to the starting number.
7.3 Review of Previous Sediment Quality Data
EPD’s Monitoring Data
7.3.1
EPD
conducts routine monitoring of bottom sediment quality at 45 stations within
the territory of Hong Kong waters, in which the nearest station is located at
Junk Bay approximately 1km to the south of the proposed CBL.
7.3.2
Table 7.3 summarizes the
sediment contaminant levels (mean values of data collected between 2005 and
2009, data in brackets indicate ranges) and their classification. The measurement parameters include heavy
metals (cadmium, chromium, copper, mercury, nickel, lead, silver, zinc,
arsenic) and organic contaminants (PAHs and PCBs). Measurement of TBT was not
provided. Based on the data, “Copper” and “Silver” exceeded the LCEL, and
therefore the sediment shall be classified as Category M.
Table 7.3 EPD sediment quality
data between 2005 and 2009 at Junk Bay
|
Contaminant |
Unit |
Mean Concentration (between 2005 and 2009) |
Sediment Classification under ETWB TC(W) No.
34/2002 |
|
Silver (Ag) |
mg/kg |
2.0 (1.6 – 3.0) |
Category M |
|
Arsenic (As) |
mg/kg |
7.4 (6.7 – 8.5) |
Category L |
|
Cadmium (Cd) |
mg/kg |
0.2 (0.1 – 0.2) |
Category L |
|
Chromium (Cr) |
mg/kg |
46 (39 – 52) |
Category L |
|
Copper (Cu) |
mg/kg |
96 (73 – 120) |
Category M |
|
Nickel (Ni) |
mg/kg |
24 (19 – 31) |
Category L |
|
Lead (Pb) |
mg/kg |
50 (41 – 54) |
Category L |
|
Zinc (Zn) |
mg/kg |
150 (110 – 160) |
Category L |
|
Mercury (Hg) |
mg/kg |
0.26 (0.17 – 0.41) |
Category L |
|
Total PCB |
µg/kg |
18 (18 – 20) |
Category L |
|
Low Molecular
Weight PAHs |
µg/kg |
97 (90 – 110) |
Category L |
|
High Molecular
Weight PAHs |
µg/kg |
250 (90 – 420) |
Category L |
7.3.3 The elevated levels of heavy metals detected in the sediments of Junk Bay could often be attributed to previous industrial pollution sources in the 1960s to 1980s before pollution control legislation was introduced (EPD, 2009).
EIA for Further Development of TKO
7.3.4
Sediment
sampling works for the EIA of Further Development of TKO were conducted in
March 2003. Vibrocore samples were collected at 6 locations. In
these 6 locations, 2 (i.e. VC5 and VC13) of them are lying on the proposed
alignment of CBL. The locations of these 2 sediment samples are presented in Drawing
no. 209506/EIA/SQ/001.
7.3.5
Appendix 7.2 presents a summary
of the measurement results at these 2 locations. All sub-samples of these 2 locations were
classified as Category L, except the following:
·
VC5, depth 0.12 – 0.9m, heavy metal “Copper”
exceeded the LCEL and is therefore classified as Category M.
·
VC13, depth 0.9 – 1.9m, heavy metal “Mercury”
exceeded the LCEL and is therefore classified as Category M.
7.3.6
No
sample was classified as Category H. The
concentrations of PAH and TBT of both samples were reported to be very low. No
Tier III Biological Screening Test was carried out for the Category M
sediment samples.
7.4 Sample Collection and Laboratory Analysis
Objectives
7.4.1
The
purpose of ground investigation for CBL is to obtain relevant information for
the geo-chemical characteristics of the seabed sediment to be excavated from
the Study Area through identification of the geological conditions, presence of
contaminants and their levels, so that the subsequent decision for the sediment
disposal arrangement could be made. The SI works were accomplished by
collecting vibrocore, grabs sediment and in-situ samples for the subsequent
laboratory analyses.
Sediment Sampling
7.4.2 The locations of the grab and vibrocore sediments were selected with a view to obtain information for the excavation works. A summary of these sampling locations is given below and illustrated in Drawing no. 209506/EIA/SQ/002. The sampling work was carried out between March and April 2010 by the Term Contractor of Geotechnical Engineering Office (GEO) of CEDD.
|
·
Grab and Vibrocore sediment samples |
Ø 12
sampling Locations: - VB1 to
VB9, VB11 and VB12 for three CBL alignment options - VB10
for the saltwater main partly submarine alignment |
|
·
Grab sample only |
Ø 1
sample at Reference Location in Port Shelter (PS6) |
7.4.3 It should be noted that the proposed saltwater main has been excluded from the scope of this EIA Study (refer to Section 1.3). Therefore, the testing results of VB10 are not presented in this EIA Report.
7.4.4
Sediment samples were
retrieved by vibrocoring in the marine deposit layer. Vibrocore of 100mm
in diameter and 4m long was deployed from marine vessels. The sediment samples were
collected at seabed level (i.e. grab sampling) and then at 0.9m, 1.9m, 2.9m
below the seabed, thereafter 3m depth intervals. The depth of sediment sampling
was terminated at base of marine deposits.
7.4.5 Grab samples of the upper deposits of seabed were collected for pore water testing at all vibrocore locations. Modified van Veen grab (or equivalent) of capacity ~2L was deployed from marine vessels and ~20L of sediment at each location was collected. All seawater trapped inside the grab during sampling was drained out carefully before any further process. After draining of seawater, individual grabs were composited on-site and split into portions for packing for laboratory pore water testing.
7.4.6 All sediment samples were kept at 4ºC during transportation and at the laboratory prior to testing. The sampling bottle and pre-treatment methods followed the recommendation stipulated in ETWB TC(W) No. 34/2002. Sediment samples were extracted in the laboratory and placed in the appropriate containers directly after the sampling. All samples were double bagged and labelled internally and externally with indelible ink. The sample holding time for chemical and biological testing was 2 weeks and 8 weeks respectively.
7.4.7 The sub-samples for biological testing were stored in the same manner as described above (including for ancillary parameters). The composite samples for biological testing (where required) comprised of up to 5 sub-samples of the same category (i.e. sediment classified under the ETWB TC(W) No. 34/2002 as Categories M or H), and continuous in a vertical or horizontal profile.
7.4.8 Marine water of ~5L was required for preparation of elutriate testing in the laboratory for each sediment sub-sample. Sufficient quantity of marine water was collected at one location during each day of vibrocoring. The sample holding time for elutriate samples was 1 week. Additional 10L of marine water was collected for each sampling location column for blank test. The locations for collecting water samples for the elutriate test and blank test were the same as the vibrocoring.
7.4.9 Reference sediment (surface grab) of ~30L was collected at Port Shelter (PS6, E850234, N820057). Modified Van Veen grab (or equivalent) of capacity ~2L was deployed from marine vessel and ~30L of sediment was collected. Individual grabs were composited on-site and split into portions for packing, of which ~4L for elutriate testing, ~20L for pore water testing, and ~6L for biological testing respectively. Sediment sample was stored at 4oC during transportation and at the laboratory prior to testing. Marine water of ~5L was collected at the same time for preparation of elutriate samples.
Laboratory Testing
Testing
for Sediment Quality Assessment
7.4.10
The sediment quality was
assessed through laboratory analyses of sediment samples at all vibrocore
locations (as in Table 7.1) for the chemical and/or biological
parameters listed in ETWB TC(W) No. 34/2002. The reference sediment
(clean sample) was also tested for comparison.
7.4.11 Chemical screening parameters include:
· 9 metals/metalloid: cadmium, chromium, copper, mercury, nickel, lead, silver, zinc and arsenic for all grab samples and vibrocore sub-samples; and
· 3 organic micro-pollutants: polyaromatic hydrocarbons (PAHs) (low and high molecular weights), polychlorinated biphenyls (PCBs) (total), tributyltin (TBT) (in pore water) for all grab samples and vibrocore sub-samples.
7.4.12 Biological screening parameters include:
·
10-day burrowing amphipod toxicity test,
·
20-day burrowing polychaete toxicity test,
and
· 48-96 hours larvae (bivalve or echinoderm) toxicity test.
7.4.13 Based on the chemical test results, the necessity and arrangement of biological tests were concluded. For every sample which required biological test based on the chemical test results and subsequent classification in accordance with the ETWBTC (Works) No. 34/2002, biological test of each sample was conducted. All analytical methods were based on the U.S. Environmental Protection Agency (U.S. EPA) or equivalent.
7.4.14 Details of the chemical and biological testing parameters, methodology and reporting limits for sediment quality assessment are summarised in Tables 7.4 and 7.5. Ancillary testing parameters including moisture content, grain size (>2000μm, 63-2000μm, and <63μm), total organic carbon, ammonia (as mg N/L), and salinity in pore water were analysed for those samples undergoing biological testing.
Table 7.4
Chemical screening parameters for sediment quality
|
Parameters |
Instrumentation |
Analytical Method |
Reporting
Limit |
|
Cadmium (Cd) |
ICP-ES & ICP-MS |
ICP-ES APHA
3030F 3b APHA
3120B ASTM D3976-92 ICP-MS APHA
3030F 3b APHA
3125 A & B ASTM
D3976-92 USEPA
3005A USEPA 6020A |
0.05 mg/kg |
|
Chromium (Cr) |
ICP-ES & ICP-MS |
0.1 mg/kg |
|
|
Copper (Cu) |
ICP-ES & ICP-MS |
0.2 mg/kg |
|
|
Mercury (Hg) |
ICP-MS |
0.05 mg/kg |
|
|
Nickel (Ni) |
ICP-ES & ICP-MS |
0.2 mg/kg |
|
|
Lead (Pb) |
ICP-ES & ICP-MS |
0.1 mg/kg |
|
|
Silver (Ag) |
ICP-ES & ICP-MS |
0.1 mg/kg |
|
|
Zinc (Zn) |
ICP-ES & ICP-MS |
0.2 mg/kg |
|
|
Arsenic (As) |
ICP-ES & ICP-MS |
0.1 mg/kg |
|
|
Total PAHs (Low MW) |
GC-MSD |
USEPA
3546, 3660B, 8630C & 8270C |
55 µg/kg(1) |
|
Total PAHs (High MW) |
GC-MSD |
55 µg/kg(1) |
|
|
Total PCBs |
GC-MSD |
USEPA 3546, 3660B, 3665A,
8082 & 8270C |
2 µg/kg(2) |
|
Tributyltin(3)
(TBT) |
GC-MSD |
UNEP/IOC/IAEA |
0.015 µg/L |
Note:
(1)
Reporting
limit for each low and high molecular weight PAH.
(2)
Reporting limit for each PCB.
(3)
In interstitial water
Table
7.5 Biological screening(1) parameters
for sediment quality
|
Toxicity Test |
Test Method |
Endpoints Measured |
Failure Criteria |
|
10-day amphipod |
USEPA Standard Methods for Assessing the Toxicity of
Sediment-associated Contaminants with Estuarine and Marine Amphipods |
Survival |
Mean survival in test sediment is significantly different (p≤
0.05)(2) from mean survival in reference sediment and mean
survival in test sediment < 80% of mean survival in reference sediment. |
|
20-day polychaete worm |
PSEP Standard Recommended Guidelines for Conducting Laboratory
Bioassays on the Pudget Sound Sediments – Juvenile Polychaete Sediment
Bioassay, 1995 |
Dry weight(3) |
Mean dry weight in test sediment is significantly different (p≤
0.05)(2) from mean dry weight in reference sediment and mean dry
weight in test sediment <90% of mean dry weight in reference sediment.
|
|
48-96 hour larvae (bivalve or echinoderm) |
PSEP Standard Recommended Guidelines for Conducting Laboratory
Bioassays on the Pudget Sound Sediments – Bivalve Larvae Sediment Bioassay,
1995 |
Normality survival(4) |
Mean normality survival in test sediment is significantly different
(p≤ 0.05)(2) from mean normality survival in reference
sediment and mean normality survival in test sediment <80% of mean
normality survival in reference sediment. |
Note:
(1)
Ancillary testing parameters to be analysed for all
sediment samples include moisture content, grain size (>2000μm,
63-2000μm, and <63μm), total organic carbon, ammonia (as mg N/L),
and salinity in porewater.
(2)
Statistically significantly differences should be
determined using appropriate two-sample composite (e.g. t-tests) at a
probability of p≤ 0.05.
(3)
Dry weight means total dry weight after deducting dead and missing
worms. \
(4)
Normality survival integrates the normality and
survival end points, and measures survival of only the normal larvae relative
to the starting number.
Elutriate and Pore Water Testing for Water Quality Assessment
7.4.15 Preparation of elutriate for vibrocore sediment sub-samples was conducted in accordance with the Evaluation of Dredged Material proposed for Discharge in Waters of the US – Testing Manual (Inland Testing Manual), USEPA and USACE, 1998. The reference sediment and marine water samples were also tested for comparison.
7.4.16
Elutriate samples were
prepared by sub-sampling approximately 1L of sediment sub-sample combined with
unfiltered marine water collected on-site in a sediment-to-water ratio of 1:4
by volume in a pre-cleaned container in the laboratory. The mixture was stirred
for 30 minutes on a platform shaker. After 30 minutes, the mixture was allowed
for settling for 1 hour and the supernatant was then siphoned off without
disturbing the settled material. The decanted solution was centrifuged to
remove particulates prior to chemical analysis (approximately 2000rpm for 30
min, until visually clear). The elutriate testing parameters include:
·
9 metals/metalloid: cadmium, chromium, copper, mercury, nickel, lead, silver, zinc and arsenic;
·
3 organic micro-pollutants: PAHs (low and high molecular weights), total PCBs and TBT; and
·
Ammonia, Nitrite, Nitrate,
Total Kjeldahl Nitrogen, Total Phosphorus, Reactive Phosphorus and Chlorinated Pesticides.
7.4.17 Preparation of pore water from all grab sediment samples was conducted in accordance with “Methods for Collection, Storage and Manipulation of Sediments for Chemical and Toxicological Analyses: Technical Manual, USEPA 2001” (or equivalent). The reference sediment was also tested for comparison.
7.4.18 Pore water samples were prepared by sub-sampling approximately 1L of sediment in a pre-cleaned container in the laboratory and centrifuged at rotation speed at 3,000rpm for 10 minutes. After that, the supernatant was decanted without disturbing the sediment material. The pore water testing parameters and assessment criteria are the same as those for elutriate samples.
7.4.19
All analytical methods were
based on U.S. EPA or equivalent. The details of elutriate and pore water
testing parameters for water quality assessment are summarised in Table 7.6
(including the reporting limits for the respective analytical methods).
Table 7.6 Chemical parameters for sediment elutriate
and pore water testing
|
Parameters |
Instrumentation |
Analytical Method |
Reporting Limit |
|
Cadmium (Cd) |
ICP-ES & ICP-MS |
ICP-ES APHA 3030F 3b APHA 3120B ASTM D3976-92 ICP-MS APHA 3030F 3b APHA 3125 A & B USEPA 3005A USEPA 6020A |
0.1 µg/L |
|
Chromium (Cr) |
ICP-ES & ICP-MS |
0.2 µg/L |
|
|
Copper (Cu) |
ICP-ES & ICP-MS |
0.2 µg/L |
|
|
Mercury (Hg) |
ICP-MS |
0.1 µg/L |
|
|
Nickel (Ni) |
ICP-ES & ICP-MS |
0.2 µg/L |
|
|
Lead (Pb) |
ICP-ES & ICP-MS |
0.2 µg/L |
|
|
Silver (Ag) |
ICP-ES & ICP-MS |
0.2 µg/L |
|
|
Zinc (Zn) |
ICP-ES & ICP-MS |
0.4 µg/L |
|
|
Arsenic (As) |
ICP-ES & ICP-MS |
0.2 µg/L |
|
|
PAHs |
GC-MSD |
USEPA 3546, 3660B, 8630C & 8270C |
0.1 µg/L(1) |
|
Total PCBs |
GC-MSD |
USEPA 8082 & 8270C |
0.01 µg/L(2) |
|
Tributyltin (TBT) |
GC-MSD |
UNEP/IOC/IAEA |
0.015 µg TBT/L |
|
Ammonia |
FIA |
APHA 4500-NH3 H |
0.01mg NH3-N/L |
|
Nitrite as N |
FIA |
APHA 4500-NO2 B |
0.01mg NO2--N/L |
|
Nitrate as N |
FIA |
APHA 4500-NO3 F |
0.01 NO3--mg/L |
|
TKN as N |
FIA |
APHA 4500-Norg A, B & D |
0.5mg N/L |
|
Total Phosphorus |
FIA |
APHA 4500-P B, E, F & H |
0.02 mg-P/L |
|
Reactive Phosphorus |
FIA |
APHA 4500-P A, F & G |
0.005 mg PO43--/L |
|
Chlorinated Pesticides: Alpha-BHC Beta- BHC Gamma-BHC Delta-BHC Heptachlor Aldrin Heptachlor epoxide Endosulfan 1 p,p'-DDE p,p'-DDD p,p'-DDT Endosulfan sulphate |
GC-MSD |
USEPA 8270C |
0.05 µg/L(3) |
Note:
(1)
Reporting
limit for both low and high molecular weights PAHs.
(2)
Reporting
limit for each PCB.
(3)
Reporting
limit for each Chlorinated Pesticides.
QA/QC
Requirements
7.4.20
Field
logs and site diary were maintained for all on-site sampling works with date, equipment used, site activities and
observations, undertaken as far as possible. Any deviation from the standard
procedures and reasons were recorded in the logs.
7.4.21
Laboratory
QA/QC requirements, including analyses by HOKLAS accredited laboratory,
certified reference materials, spike recovery, blank samples, duplicate
samples (for every 20 samples), negative/positive control for biological test,
etc. were strictly followed.
7.5 Sediment Quality and Classification
Chemical
screening test
7.5.1 There were in total 90 sub-samples from 11 vibrocore and 11 grab samples from each of the vibrocore sampling locations (i.e. the sampling location VB10 is excluded). The detailed results of chemical screening test of the sediment samples are summarised in Table 7.7.
7.5.2 The levels of cadmium, chromium, mercury, nickel, and silver were all below LCELs with concentration ranged from:
·
Cadmium : <0.05 - 1.4 mg/kg,
· Chromium: 4.4 - 50 mg/kg,
· Mercury: <0.05 - 0.23 mg/kg,
· Nickel: 2.5 - 25 mg/kg,
· Silver: <0.1 - 0.1 mg/kg
7.5.3 The concentrations of PAHs, PCBs, TBT were all below the LCELs.
7.5.4 The levels of copper, lead, zinc, and arsenic have exceeded LCELs in some of the sub-samples including most of the grab samples. On the other hand, the level of zinc in 2 sub-samples VB3 (0.2-0.9m) and VB11 (1.9-2.9m) have exceeded the UCEL. The maximum concentrations of these metals were 106mg/kg for copper, 105mg/kg for lead, 400mg/kg for zinc and 15mg/kg for arsenic.
7.5.5 Based on the chemical test results, 78 vibrocore sub-samples with no exceedance of LCELs were classified as Category L, whilst the 2 sub-samples VB3 (0.2-0.9m) and VB11 (1.9-2.9m) which each have an exceedence of UCEL was classified as Category H. The remaining 10 sub-samples with levels of contaminants exceeded LCELs were classified as Category M and were further tested on the biological screening tests.
Table 7.7 Sediment Chemical Quality Data and Proposed
Biological Tests
|
Sampling Location |
Sampling Depth (meter below seabed level) |
Metals and Metalloid (mg/kg in dry wt. basis) |
Organics (μg/kg
in dry wt. basis) |
Organo-metallic (μg
TBT/L) |
Overall Classification under ETWB TC(W) No.
34/2002 |
Biological Test |
||||||||||
|
Cd |
Cr |
Cu |
Hg |
Ni |
Pb |
Ag |
Zn |
As |
Total PCB |
LMW PAHs |
HMW PAHs |
Tributyltin - Soluble |
||||
|
VB1 |
Grab Sample |
0.13 |
31 |
73 |
0.11 |
15 |
40 |
0.1 |
106 |
4.3 |
All PCB
congeners are <2 μg/kg |
<330 |
<550 |
<0.015 |
M |
√ |
|
0.0-0.9 |
0.28 |
32 |
85 |
0.11 |
13 |
61 |
<0.1 |
160 |
3.6 |
<330 |
<550 |
<0.015 |
M |
√ |
||
|
0.9-1.9 |
<0.05 |
37 |
57 |
0.14 |
19 |
41 |
<0.1 |
128 |
4.3 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
1.9-2.9 |
<0.05 |
24 |
4.8 |
0.15 |
18 |
14 |
<0.1 |
60 |
1.7 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
4.9-5.9 |
<0.05 |
26 |
6.3 |
0.09 |
18 |
18 |
<0.1 |
58 |
2.3 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
7.9-8.9 |
<0.05 |
28 |
7.9 |
<0.05 |
20 |
24 |
<0.1 |
64 |
3.8 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
10.9-11.9 |
<0.05 |
29 |
8.3 |
<0.05 |
21 |
31 |
<0.1 |
66 |
6.3 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
13.9-14.9 |
<0.05 |
9.2 |
4.6 |
<0.05 |
2.8 |
8.0 |
<0.1 |
11 |
2.6 |
<330 |
<550 |
IS |
L |
- |
||
|
16.3-17.3 |
<0.05 |
23 |
8.9 |
<0.05 |
16 |
23 |
<0.1 |
54 |
6.8 |
<330 |
<550 |
IS |
L |
- |
||
|
VB2 |
Grab Sample |
<0.05 |
28 |
58 |
0.08 |
15 |
34 |
<0.1 |
62 |
5.1 |
All PCB
congeners are <2 μg/kg |
<330 |
<550 |
<0.015 |
L |
- |
|
0.1-0.9 |
<0.05 |
5.8 |
18 |
<0.05 |
8.1 |
21 |
<0.1 |
26 |
2.5 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
0.9-1.9 |
<0.05 |
7.8 |
3.9 |
<0.05 |
6.3 |
17 |
<0.1 |
22 |
2.1 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
1.9-2.9 |
<0.05 |
27 |
7.9 |
<0.05 |
21 |
21 |
<0.1 |
64 |
3.6 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
4.9-5.9 |
<0.05 |
29 |
8.4 |
<0.05 |
22 |
28 |
<0.1 |
64 |
2.8 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
7.9-8.9 |
<0.05 |
33 |
10 |
<0.05 |
25 |
30 |
<0.1 |
71 |
3.9 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
10.9-11.9 |
<0.05 |
25 |
8.2 |
<0.05 |
18 |
34 |
<0.1 |
58 |
7.4 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
12.0-13.0 |
<0.05 |
24 |
5.9 |
<0.05 |
8.7 |
18 |
<0.1 |
24 |
9.8 |
<330 |
<550 |
IS |
L |
- |
||
|
VB3 |
Grab Sample |
0.13 |
35 |
63 |
0.09 |
18 |
59 |
0.1 |
124 |
4.9 |
All PCB
congeners are <2 μg/kg |
<330 |
<550 |
<0.015 |
L |
- |
|
0.2-0.9 |
1.4 |
50 |
106 |
0.13 |
17 |
105 |
<0.1 |
400 |
4.2 |
<330 |
<550 |
<0.015 |
H |
- |
||
|
0.9-1.9 |
0.16 |
25 |
31 |
0.10 |
13 |
56 |
<0.1 |
84 |
2.7 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
1.9-2.9 |
<0.05 |
25 |
8.5 |
<0.05 |
19 |
20 |
<0.1 |
83 |
1.2 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
4.9-5.9 |
<0.05 |
29 |
8.3 |
<0.05 |
21 |
20 |
<0.1 |
66 |
1.6 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
7.9-8.9 |
<0.05 |
29 |
10 |
<0.05 |
21 |
23 |
<0.1 |
70 |
2.6 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
10.9-11.9 |
<0.05 |
27 |
8.7 |
<0.05 |
20 |
29 |
<0.1 |
62 |
5.6 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
13.9-14.9 |
<0.05 |
5.2 |
2.8 |
<0.05 |
2.5 |
14 |
<0.1 |
22 |
2.6 |
<330 |
<550 |
IS |
L |
- |
||
|
VB4 |
Grab Sample |
0.17 |
40 |
86 |
0.17 |
19 |
49 |
0.1 |
126 |
5.3 |
All PCB
congeners are <2 μg/kg |
<330 |
<550 |
<0.015 |
M |
√ |
|
0.0-0.9 |
<0.05 |
29 |
58 |
0.23 |
13 |
41 |
<0.1 |
101 |
4.3 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
0.9-1.9 |
<0.05 |
24 |
13 |
0.21 |
17 |
32 |
<0.1 |
76 |
2.6 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
1.9-2.9 |
<0.05 |
24 |
5.5 |
0.20 |
18 |
15 |
<0.1 |
58 |
1.8 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
4.9-5.9 |
<0.05 |
24 |
6.5 |
0.20 |
17 |
17 |
<0.1 |
54 |
1.1 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
7.9-8.9 |
<0.05 |
28 |
7.4 |
0.10 |
19 |
21 |
<0.1 |
60 |
2.1 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
10.9-11.9 |
<0.05 |
28 |
8.5 |
<0.05 |
21 |
27 |
<0.1 |
64 |
5.6 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
13.9-14.9 |
<0.05 |
21 |
6.4 |
<0.05 |
6.7 |
22 |
<0.1 |
23 |
2.1 |
<330 |
<550 |
IS |
L |
- |
||
|
15.9-16.7 |
<0.05 |
34 |
8.2 |
<0.05 |
11 |
13 |
<0.1 |
28 |
9.6 |
<330 |
<550 |
IS |
L |
- |
||
|
VB5 |
Grab Sample |
0.18 |
29 |
76 |
<0.05 |
13 |
45 |
0.1 |
97 |
4.1 |
All PCB
congeners are <2 μg/kg |
<330 |
<550 |
<0.015 |
M |
√ |
|
01-0.9 |
0.21 |
16 |
35 |
0.10 |
11 |
74 |
<0.1 |
93 |
4.7 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
0.9-1.9 |
<0.05 |
41 |
44 |
<0.05 |
21 |
56 |
<0.1 |
119 |
5.6 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
1.9-2.9 |
<0.05 |
26 |
7.2 |
<0.05 |
20 |
19 |
<0.1 |
61 |
4.1 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
4.9-5.9 |
<0.05 |
24 |
7.2 |
<0.05 |
18 |
20 |
<0.1 |
56 |
2.3 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
7.9-8.9 |
0.05 |
25 |
8.5 |
<0.05 |
19 |
31 |
<0.1 |
53 |
3.0 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
10.9-11.9 |
<0.05 |
24 |
8.6 |
<0.05 |
19 |
32 |
<0.1 |
57 |
7.2 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
12.8-13.8 |
<0.05 |
10 |
6.1 |
<0.05 |
6.6 |
26 |
<0.1 |
36 |
7.6 |
<330 |
<550 |
IS |
L |
- |
||
|
VB6 |
Grab Sample |
0.19 |
33 |
85 |
0.09 |
14 |
45 |
0.2 |
103 |
4.7 |
All PCB
congeners are <2 μg/kg |
<330 |
<550 |
<0.015 |
M |
√ |
|
0.1-0.9 |
<0.05 |
43 |
54 |
0.06 |
20 |
40 |
<0.1 |
114 |
3.9 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
0.9-1.9 |
<0.05 |
37 |
38 |
<0.05 |
18 |
48 |
<0.1 |
117 |
4.1 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
1.9-2.9 |
<0.05 |
22 |
5 |
<0.05 |
16 |
14 |
<0.1 |
55 |
2.0 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
4.9-5.9 |
<0.05 |
24 |
6.8 |
<0.05 |
18 |
19 |
<0.1 |
55 |
1.6 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
7.9-8.9 |
<0.05 |
29 |
8.5 |
<0.05 |
21 |
23 |
<0.1 |
62 |
1.7 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
10.9-11.9 |
<0.05 |
29 |
9.1 |
<0.05 |
21 |
27 |
<0.1 |
62 |
3.7 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
13.9-14.9 |
<0.05 |
24 |
8.1 |
<0.05 |
18 |
30 |
<0.1 |
55 |
7.0 |
<330 |
<550 |
IS |
L |
- |
||
|
14.9-15.7 |
<0.05 |
11 |
1.9 |
<0.05 |
3.7 |
39 |
<0.1 |
26 |
15 |
<330 |
<550 |
IS |
M |
√ |
||
|
0.1-0.9 |
<0.05 |
23 |
8.5 |
0.16 |
16 |
17 |
<0.1 |
55 |
2.5 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
VB7 |
Grab Sample |
0.33 |
36 |
96 |
0.11 |
19 |
66 |
0.1 |
230 |
7.1 |
All PCB
congeners are <2 μg/kg |
<330 |
<550 |
<0.015 |
M |
√ |
|
0.9-1.9 |
<0.05 |
42 |
58 |
0.11 |
19 |
48 |
<0.1 |
121 |
5.5 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
1.9-2.9 |
<0.05 |
21 |
3.7 |
<0.05 |
16 |
14 |
<0.1 |
53 |
1.3 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
4.9-5.9 |
<0.05 |
22 |
5.3 |
<0.05 |
17 |
15 |
<0.1 |
53 |
1.7 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
7.9-8.9 |
<0.05 |
28 |
6.8 |
<0.05 |
20 |
22 |
<0.1 |
63 |
1.7 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
10.9-11.9 |
<0.05 |
29 |
7.7 |
<0.05 |
21 |
24 |
<0.1 |
64 |
2.8 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
13.9-14.9 |
<0.05 |
25 |
7.4 |
<0.05 |
18 |
29 |
<0.1 |
59 |
7.7 |
<330 |
<550 |
IS |
L |
- |
||
|
VB8 |
Grab Sample |
<0.05 |
25 |
54 |
0.09 |
11 |
34 |
<0.1 |
97 |
5.2 |
All PCB congeners
are <2 μg/kg |
<330 |
<550 |
<0.015 |
L |
- |
|
0.2-0.9 |
<0.05 |
30 |
39 |
<0.05 |
16 |
41 |
<0.1 |
132 |
3.6 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
0.9-1.9 |
<0.05 |
23 |
6.2 |
<0.05 |
17 |
17 |
<0.1 |
59 |
2.1 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
1.9-2.9 |
<0.05 |
23 |
5.2 |
<0.05 |
17 |
15 |
<0.1 |
58 |
1.3 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
4.9-5.9 |
<0.05 |
25 |
6.9 |
<0.05 |
18 |
18 |
<0.1 |
57 |
1.2 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
7.9-8.9 |
<0.05 |
27 |
7.9 |
<0.05 |
20 |
26 |
<0.1 |
60 |
3.2 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
10.9-11.9 |
<0.05 |
23 |
7.8 |
<0.05 |
17 |
34 |
<0.1 |
56 |
7.0 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
12.3-13.3 |
<0.05 |
7.9 |
3.8 |
<0.05 |
4 |
58 |
<0.1 |
26 |
3.2 |
<330 |
<550 |
IS |
L |
- |
||
|
VB9 |
Grab Sample |
0.15 |
34 |
73 |
0.10 |
16 |
55 |
0.1 |
192 |
5.0 |
All PCB
congeners are <2 μg/kg |
<330 |
<550 |
<0.015 |
M |
√ |
|
0.5-0.9 |
0.18 |
26 |
64 |
0.08 |
12 |
54 |
<0.1 |
119 |
4.0 |
<330 |
<550 |
IS |
L |
- |
||
|
0.9-1.9 |
<0.05 |
23 |
12 |
<0.05 |
17 |
25 |
<0.1 |
68 |
3.6 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
1.9-2.9 |
<0.05 |
24 |
6.8 |
<0.05 |
18 |
17 |
<0.1 |
60 |
2.6 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
4.9-5.9 |
<0.05 |
23 |
6.9 |
<0.05 |
17 |
19 |
<0.1 |
53 |
1.8 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
7.9-8.9 |
<0.05 |
29 |
8.5 |
<0.05 |
21 |
25 |
<0.1 |
62 |
3.4 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
10.9-11.9 |
<0.05 |
24 |
8.7 |
<0.05 |
18 |
36 |
<0.1 |
59 |
7.4 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
13.9-14.9 |
<0.05 |
5.3 |
2.8 |
<0.05 |
1.6 |
18 |
<0.1 |
7.9 |
5.2 |
<330 |
<550 |
IS |
L |
- |
||
|
VB11 |
Grab Sample |
0.20 |
37 |
73 |
0.17 |
19 |
70 |
0.1 |
159 |
5.5 |
All PCB
congeners are <2 μg/kg |
<330 |
<550 |
<0.015 |
M |
√ |
|
0.5-0.9 |
0.13 |
26 |
38 |
0.09 |
11 |
48 |
<0.1 |
85 |
3.0 |
<330 |
<550 |
IS |
L |
- |
||
|
0.9-1.9 |
0.47 |
45 |
90 |
0.21 |
16 |
67 |
<0.1 |
317 |
3.7 |
<330 |
<550 |
<0.015 |
H |
- |
||
|
1.9-2.9 |
<0.05 |
31 |
18 |
<0.05 |
23 |
35 |
<0.1 |
93 |
4.3 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
4.9-5.9 |
<0.05 |
30 |
8.9 |
<0.05 |
23 |
24 |
<0.1 |
69 |
3.4 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
7.9-8.9 |
<0.05 |
30 |
11 |
<0.05 |
23 |
31 |
<0.1 |
68 |
4.5 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
10.9-11.9 |
<0.05 |
4.4 |
7.6 |
<0.05 |
2.9 |
38 |
<0.1 |
17 |
7.1 |
<330 |
<550 |
IS |
L |
- |
||
|
VB12 |
Grab Sample |
0.12 |
37 |
69 |
0.14 |
18 |
60 |
0.1 |
130 |
5.0 |
All PCB
congeners are <2 μg/kg |
<330 |
<550 |
<0.015 |
M |
√ |
|
0.1-0.9 |
<0.05 |
17 |
16 |
<0.05 |
11 |
27 |
<0.1 |
58 |
7.2 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
0.9-1.9 |
0.16 |
44 |
56 |
0.35 |
18 |
68 |
<0.1 |
124 |
4.7 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
1.9-2.9 |
<0.05 |
28 |
6.5 |
<0.05 |
23 |
20 |
<0.1 |
70 |
3.4 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
4.9-5.9 |
<0.05 |
28 |
8.4 |
<0.05 |
21 |
23 |
<0.1 |
64 |
3.5 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
7.9-8.9 |
<0.05 |
32 |
10 |
<0.05 |
25 |
33 |
<0.1 |
71 |
4.2 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
10.9-11.9 |
<0.05 |
27 |
9 |
<0.05 |
21 |
35 |
<0.1 |
64 |
11 |
<330 |
<550 |
<0.015 |
L |
- |
||
|
12.6-13.6 |
<0.05 |
5.6 |
1.4 |
<0.05 |
2.5 |
21 |
<0.1 |
15 |
1.9 |
<330 |
<550 |
IS |
L |
- |
||
|
Port Shelter |
Grab Sample
(Reference Sediment Sample) |
<0.05 |
20 |
9.8 |
0.1 |
14 |
26 |
<0.1 |
59 |
5.6 |
All PCB
congeners are <2 μg/kg |
<330 |
<550 |
<0.015 |
- - |
- - |
Note:
1. IS: Insufficient interstitial water for TBT analysis
2. Bold value denotes contaminate level exceeds the Lower Chemical Exceedance Level (LCEL)
3.
Italic
value denotes contaminate level exceeds the Upper Chemical Exceedance Level
(UCEL)
4.
Low
molecular weight PAHs includes naphthalene, acenaphthylene. acenaphthene,
fluorene, phenanthrene and anthracene; high molecular weight PAHs include
chrysene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene,
benzo(a)pyrene, dibenzo(a.h.)anthracene, fluoranthene, indeno(1.2.3-cd)pyrene,
pyrene and benzo(g.h.i)perylene; and
5. Total PCBs include 2,4' dichlorobiphenyl, 2,2',5 trichlorobiphenyl, 2,4',4 trichlorobiphenyl, 2,2',3,5 tetrachlrobiphenyl, 2,2',5,5' tetrachlrobiphenyl, 2,3',4,4' tetrachlrobiphenyl, 3,3',4,4' tetrachlrobiphenyl, 2,2',4,5,5' pentachlrobiphenyl, 2,3,3',4,4' pentachlrobiphenyl, 2,3',4,4',5' pentachlrobiphenyl, 3,3',4,4,5' pentachlrobiphenyl, 2,2',3,3',4,4' hexachlrobiphenyl, 2,2',3,4,4',5' hexachlrobiphenyl, 2,2',4,4',5,5' hexachlrobiphenyl, 3,3',4,4',5,5' hexachlrobiphenyl, 2,2',3,3',4,4',5 heptachlrobiphenyl, 2,2',3,4,4',5,5' heptachlrobiphenyl and 2,2'3,4',5,5',6 heptachlrobiphenyl.
Biological screening test
7.5.6 Biological screening tests are required for the 10 Category M sediments. Table 7.8 summarises the samples requiring biological screening tests.
7.5.7 The results of 10-day burrowing amphipod toxicity test, 20-day burrowing polychaete toxicity test, and 48-hour bivalve larvae toxicity test are summarised in Tables 7.9 – 7.11. The results of ancillary parameters including grain size, moisture content, total organic carbon (TOC), ammonia, and salinity are summarised in Table 7.12.
7.5.8 The results showed that all the samples passed the biological tests except the Composite Sample VB1 (i.e. composited of VB1 Grab Sample & VB1 (0.0-0.9m)), VB6 Grab Sample and VB6 (14.9-15.7m) which failed in the 48-hour bivalve larvae test, as the mean normality survival percentage in these samples were more than 80% in relation to the reference and were significantly different from that of the reference sediment.
7.5.9 The levels of moisture content and TOC content ranged from 44 - 65% and from 0.13 - 0.45%, respectively. Levels of interstitial salinity were all found to be 32ppt except for VB6 (14.9-15.7m) and VB7 (grab sample) which were 31ppt. The levels of interstitial ammonia was between <0.05 and 0.06 mgNH3/L. The size spectrum of >2000 μm, 63-2000 μm, and <63 μm ranges from 0.6 - 2.3%, 13 - 24%, and 56 - 86.1%, respectively.
Table
7.8 Sediment samples requiring biological
screening tests
|
Sampling Location |
Sampling Depth (meter below seabed level) |
Composite Sample |
|
VB1 |
Composite
of VB1 Grab Sample and VB1 (0.0-0.9m) |
-- |
|
VB1 |
0.0-0.9 |
Yes |
|
VB4 |
Grab Sample |
|
|
VB5 |
Grab Sample |
-- |
|
VB6 |
Grab Sample |
-- |
|
VB6 |
14.9-15.7 |
-- |
|
VB7 |
Grab Sample |
-- |
|
VB9 |
Grab Sample |
-- |
|
VB11 |
Grab Sample |
-- |
|
VB12 |
Grab Sample |
-- |
Table 7.9 Amphipod survival in relation to reference
sediment
|
Sampling
Location |
Sampling
Depth (meter below seabed level) |
Mean
Survival (%) |
Survival
in relation to reference (%)(1) |
Results |
|
Reference |
- |
92.0 |
- |
- |
|
VB1 |
Composite of
VB1 Grab Sample and VB1 (0.0-0.9m) |
93.0 |
101.1 |
Pass |
|
VB4 |
Grab sample |
91.0 |
98.9 |
Pass |
|
VB5 |
Grab sample |
87.0 |
94.6 |
Pass |
|
VB6 |
Grab sample |
88.0 |
95.7 |
Pass |
|
VB6 |
14.9-15.7 |
89.0 |
96.7 |
Pass |
|
VB7 |
Grab sample |
89.0 |
96.7 |
Pass |
|
VB9 |
Grab sample |
85.0 |
92.4 |
Pass |
|
VB11 |
Grab sample |
85.0 |
92.4 |
Pass |
|
VB12 |
Grab sample |
92.0 |
100.0 |
Pass |
Table 7.10 Total dry weight of polychaete
in relation to reference sediment
|
Sampling
Location |
Sampling
Depth (meter below seabed level) |
Mean
Total Dry Weight (mg) |
Total
dry weight in relation to reference (%)(1) |
Results |
|
Reference |
- |
86.9 |
- |
- |
|
VB1 |
Composite of
VB1 Grab Sample and VB1 (0.0-0.9m) |
96.7 |
111.3 |
Pass |
|
VB4 |
Grab sample |
99.5 |
114.5 |
Pass |
|
VB5 |
Grab sample |
87.8 |
101.0 |
Pass |
|
VB6 |
Grab sample |
88.9 |
102.3 |
Pass |
|
VB6 |
14.9-15.7 |
101.5 |
116.8 |
Pass |
|
VB7 |
Grab sample |
107.9 |
124.2 |
Pass |
|
VB9 |
Grab sample |
100.5 |
115.7 |
Pass |
|
VB11 |
Grab sample |
90.8 |
104.5 |
Pass |
|
VB12 |
Grab sample |
88.2 |
101.5 |
Pass |
Note:
(1)
As the average total dry
weight of polychaete for test sediment was greater than 90% of that of the reference
sediment, statistical analysis was not required.
Table 7.11 Normality survival bivalve larvae in
relation to reference sediment
|
Sampling
Location |
Sampling
Depth (meter below seabed level) |
Mean
Normality Survival (%) |
Normal
survival in relation to reference (%) |
Results |
|
Reference |
- |
84.3 |
- |
- |
|
VB1 |
Composite of
VB1 (0.0-0.9m) and grab sample |
67.1 |
79.6 (1) |
Fail |
|
VB4 |
Grab sample |
79.0 |
93.7 |
Pass |
|
VB5 |
Grab sample |
74.8 |
88.7 |
Pass |
|
VB6 |
Grab sample |
53.4 |
63.3 (1) |
Fail |
|
VB6 |
14.9-15.7 |
61.5 |
73.0 (1) |
Fail |
|
VB7 |
Grab sample |
76.9 |
91.2 |
Pass |
|
VB9 |
Grab sample |
76.6 |
90.9 |
Pass |
|
VB11 |
Grab sample |
80.0 |
94.9 |
Pass |
|
VB12 |
Grab sample |
80.6 |
95.6 |
Pass |
Note:
(1)
Mean normality survival in test
sediment is <80% in relation to reference sediment and is significantly
different (p<0.05) from that in reference sediment
Table 7. 12 Ancillary test results
|
Sampling
Location |
Sampling
Depth (meter below seabed level) |
Interstitial
Ammonia (mgNH3/L) |
Interstitial
Salinity (ppt) |
Size
Spectrum (percentage of sand/silt/clay, >2000μm),
% |
Size
Spectrum (63-2000μm),
% |
Size
Spectrum (<63μm) ,% |
Moisture
Content (%) |
Total
Organic Carbon (%) |
|
VB1 |
Composite of
VB1 (0.0-0.9m) and grab sample |
0.05 |
32 |
2.1 |
24 |
73.9 |
44 |
0.31 |
|
VB4 |
Grab Sample |
0.06 |
32 |
1.2 |
16 |
82.8 |
55 |
0.45 |
|
VB5 |
Grab Sample |
<0.05 |
32 |
0.9 |
13 |
86.1 |
55 |
0.44 |
|
VB6 |
Grab Sample |
0.05 |
32 |
0.9 |
22 |
77.1 |
49 |
0.33 |
|
VB6 |
14.9-15.7 |
<0.05 |
31 |
11 |
33 |
56.0 |
24 |
0.13 |
|
VB7 |
Grab Sample |
0.06 |
31 |
2.3 |
19 |
78.7 |
65 |
0.37 |
|
VB9 |
Grab Sample |
0.05 |
32 |
0.6 |
19 |
80.4 |
65 |
0.45 |
|
VB11 |
Grab Sample |
0.06 |
32 |
1.2 |
16 |
82.8 |
61 |
0.43 |
|
VB12 |
Grab Sample |
0.05 |
32 |
1.3 |
21 |
77.7 |
61 |
0.34 |
Elutriate Samples
7.5.10 Elutriate tests were conducted for the purpose of water quality assessment (see Section 8) to test the extent of contaminant release when excavation activities take place. The testing parameters included heavy metals (cadmium, chromium, copper, mercury, nickel, lead, zinc and silver), metalloid (arsenic) and organic micro-pollutants (PCB, PAH and TBT), chlorinated pesticides and nutrients including NH3-N, NO2-H, NO3-N, TKN, PO4-P, and total phosphorus.
7.5.11 The elutriate test results are summarised in Tables 7.3 and 7.14. In general, the levels of PAHs, PCBs and TBT were all below the reporting limits.
Pore Water Samples
7.5.12 Pore water tests were conducted (i.e. for grab samples only) also for the purpose of water quality assessment (see Section 8) of the potential of contaminant release when filling activities take place. The testing parameters included heavy metals (cadmium, chromium, copper, mercury, nickel, lead, zinc and silver), metalloid (arsenic) and organic micro-pollutants (PCB, PAH and TBT), chlorinated pesticides and nutrients including NH3-N, NO2-H, NO3-N, TKN, PO4-P, and total phosphorus.
7.5.13 The pore water test results of this investigation are summarised in Tables 7.15 and 7.16. In general, the levels of PAHs, PCBs and TBT were all below the reporting limits.
Table 7.13 Elutriate test results (Metals, Metalloid
and PAHs)
|
Sampling Location |
Sampling Depth (meter below seabed level) |
Metals (μg/L) |
Metalloid (μg/L) |
Organic-PAHs (μg/L) |
||||||||
|
Cd |
Cr |
Cu |
Hg |
Ni |
Pb |
Ag |
Zn |
As |
LMW PAH |
HMW PAH |
||
|
VB1 |
Ambient water |
<0.1 |
4.8 |
37 |
<0.1 |
2.3 |
33 |
<0.2 |
41 |
21 |
<0.1 |
<0.1 |
|
0.0-0.9 |
<0.1 |
12.0 |
57 |
<0.1 |
4.6 |
41 |
<0.2 |
65 |
16 |
<0.1 |
<0.1 |
|
|
0.9-1.9 |
<0.1 |
6.7 |
35 |
<0.1 |
2.7 |
38 |
<0.2 |
29 |
21 |
<0.1 |
<0.1 |
|
|
1.9-2.9 |
<0.1 |
21 |
32 |
<0.1 |
12.0 |
31 |
<0.2 |
34 |
33 |
<0.1 |
<0.1 |
|
|
4.9-5.9 |
<0.1 |
7.3 |
33 |
<0.1 |
3.0 |
35 |
<0.2 |
30 |
14 |
<0.1 |
<0.1 |
|
|
7.9-8.9 |
<0.1 |
22 |
36 |
<0.1 |
13 |
32 |
<0.2 |
80 |
13 |
<0.1 |
<0.1 |
|
|
10.9-11.9 |
<0.1 |
6.5 |
33 |
<0.1 |
3.1 |
35 |
<0.2 |
25 |
12 |
<0.1 |
<0.1 |
|
|
13.9-14.9 |
<0.1 |
6.7 |
34 |
<0.1 |
1.2 |
28 |
<0.2 |
20 |
13 |
<0.1 |
<0.1 |
|
|
16.3-17.3 |
<0.1 |
5.3 |
34 |
<0.1 |
2.4 |
38 |
<0.2 |
17 |
12 |
<0.1 |
<0.1 |
|
|
VB2 |
Ambient water |
<0.1 |
2.8 |
43 |
<0.1 |
7.0 |
55 |
<0.2 |
7.2 |
34 |
<0.1 |
<0.1 |
|
0.1-0.9 |
<0.1 |
1.5 |
43 |
<0.1 |
4.4 |
57 |
<0.2 |
7.8 |
40 |
<0.1 |
<0.1 |
|
|
0.9-1.9 |
<0.1 |
1.3 |
42 |
<0.1 |
5.3 |
52 |
<0.2 |
7.0 |
41 |
<0.1 |
<0.1 |
|
|
1.9-2.9 |
<0.1 |
2.0 |
42 |
<0.1 |
4.8 |
51 |
<0.2 |
6.4 |
35 |
<0.1 |
<0.1 |
|
|
4.9-5.9 |
<0.1 |
2.0 |
43 |
<0.1 |
4.4 |
52 |
<0.2 |
6.2 |
33 |
<0.1 |
<0.1 |
|
|
7.9-8.9 |
<0.1 |
1.8 |
44 |
<0.1 |
5.4 |
61 |
<0.2 |
6.5 |
36 |
<0.1 |
<0.1 |
|
|
10.9-11.9 |
<0.1 |
1.3 |
44 |
<0.1 |
4.0 |
52 |
<0.2 |
8.1 |
31 |
<0.1 |
<0.1 |
|
|
12.0-13.0 |
<0.1 |
1.7 |
43 |
<0.1 |
6.2 |
53 |
<0.2 |
8.7 |
32 |
<0.1 |
<0.1 |
|
|
VB3 |
Ambient water |
<0.1 |
4.7 |
35 |
<0.1 |
0.4 |
32 |
<0.2 |
18 |
13 |
<0.1 |
<0.1 |
|
0.2-0.9 |
<0.1 |
5.1 |
34 |
<0.1 |
3.7 |
34 |
<0.2 |
32 |
19 |
<0.1 |
<0.1 |
|
|
0.9-1.9 |
<0.1 |
4.4 |
34 |
<0.1 |
2.3 |
33 |
<0.2 |
85 |
22 |
<0.1 |
<0.1 |
|
|
1.9-2.9 |
<0.1 |
8.0 |
33 |
<0.1 |
2.9 |
37 |
<0.2 |
20 |
20 |
<0.1 |
<0.1 |
|
|
4.9-5.9 |
<0.1 |
6.0 |
71 |
<0.1 |
2.4 |
32 |
<0.2 |
16 |
26 |
<0.1 |
<0.1 |
|
|
7.9-8.9 |
<0.1 |
6.6 |
37 |
<0.1 |
2.6 |
36 |
<0.2 |
21 |
21 |
<0.1 |
<0.1 |
|
|
10.9-11.9 |
<0.1 |
8.6 |
36 |
<0.1 |
2.9 |
48 |
<0.2 |
35 |
6.9 |
<0.1 |
<0.1 |
|
|
13.9-14.9 |
<0.1 |
6.2 |
34 |
<0.1 |
2.9 |
36 |
<0.2 |
17 |
18 |
<0.1 |
<0.1 |
|
|
VB4 |
Ambient water |
<0.1 |
5.2 |
41 |
<0.1 |
1.6 |
32 |
<0.2 |
17 |
8.1 |
<0.1 |
<0.1 |
|
0.0-0.9 |
<0.1 |
6.8 |
38 |
<0.1 |
2.9 |
38 |
<0.2 |
28 |
16 |
<0.1 |
<0.1 |
|
|
0.9-1.9 |
<0.1 |
4.7 |
31 |
<0.1 |
1.2 |
34 |
<0.2 |
7.9 |
37 |
<0.1 |
<0.1 |
|
|
1.9-2.9 |
<0.1 |
7.4 |
33 |
<0.1 |
3.3 |
35 |
<0.2 |
42 |
24 |
<0.1 |
<0.1 |
|
|
4.9-5.9 |
<0.1 |
6.3 |
34 |
<0.1 |
1.9 |
35 |
<0.2 |
13 |
18 |
<0.1 |
<0.1 |
|
|
7.9-8.9 |
<0.1 |
4.9 |
33 |
<0.1 |
1.8 |
29 |
<0.2 |
13 |
23 |
<0.1 |
<0.1 |
|
|
10.9-11.9 |
<0.1 |
4.0 |
32 |
<0.1 |
0.8 |
34 |
<0.2 |
8.6 |
15 |
<0.1 |
<0.1 |
|
|
13.9-14.9 |
<0.1 |
5.5 |
33 |
<0.1 |
0.5 |
37 |
<0.2 |
12 |
17 |
<0.1 |
<0.1 |
|
|
15.9-16.7 |
<0.1 |
5.8 |
35 |
<0.1 |
1.8 |
36 |
<0.2 |
61 |
12 |
<0.1 |
<0.1 |
|
|
VB5 |
Ambient water |
<0.1 |
1.0 |
40 |
<0.1 |
7.1 |
51 |
<0.2 |
0.8 |
33 |
<0.1 |
<0.1 |
|
0.1-0.9 |
<0.1 |
1.4 |
39 |
<0.1 |
3.7 |
50 |
<0.2 |
0.8 |
36 |
<0.1 |
<0.1 |
|
|
0.9-1.9 |
<0.1 |
2.1 |
38 |
<0.1 |
5.0 |
55 |
<0.2 |
1.3 |
32 |
<0.1 |
<0.1 |
|
|
1.9-2.9 |
<0.1 |
2.0 |
39 |
<0.1 |
5.7 |
53 |
<0.2 |
2.4 |
36 |
<0.1 |
<0.1 |
|
|
4.9-5.9 |
<0.1 |
2.4 |
39 |
<0.1 |
5.2 |
50 |
<0.2 |
2.4 |
38 |
<0.1 |
<0.1 |
|
|
7.9-8.9 |
<0.1 |
2.1 |
39 |
<0.1 |
4.8 |
51 |
<0.2 |
2.5 |
36 |
<0.1 |
<0.1 |
|
|
10.9-11.9 |
<0.1 |
2.2 |
42 |
<0.1 |
6.9 |
58 |
<0.2 |
8.4 |
36 |
<0.1 |
<0.1 |
|
|
12.8-13.8 |
<0.1 |
1.3 |
43 |
<0.1 |
3.6 |
54 |
<0.2 |
2.8 |
29 |
<0.1 |
<0.1 |
|
|
VB6 |
Ambient water |
<0.1 |
1.4 |
42 |
<0.1 |
5.3 |
58 |
<0.2 |
1.2 |
40 |
<0.1 |
<0.1 |
|
0.1-0.9 |
<0.1 |
1.9 |
40 |
<0.1 |
6.1 |
51 |
<0.2 |
<0.4 |
34 |
<0.1 |
<0.1 |
|
|
0.9-1.9 |
<0.1 |
1.3 |
40 |
<0.1 |
6.2 |
55 |
<0.2 |
<0.4 |
41 |
<0.1 |
<0.1 |
|
|
1.9-2.9 |
<0.1 |
1.3 |
40 |
<0.1 |
4.1 |
57 |
<0.2 |
0.6 |
38 |
<0.1 |
<0.1 |
|
|
4.9-5.9 |
<0.1 |
1.7 |
41 |
<0.1 |
4.9 |
56 |
<0.2 |
0.5 |
39 |
<0.1 |
<0.1 |
|
|
7.9-8.9 |
<0.1 |
1.8 |
41 |
<0.1 |
5.0 |
50 |
<0.2 |
0.9 |
36 |
<0.1 |
<0.1 |
|
|
10.9-11.9 |
<0.1 |
2.1 |
43 |
<0.1 |
4.1 |
57 |
<0.2 |
1.6 |
30 |
<0.1 |
<0.1 |
|
|
13.9-14.9 |
<0.1 |
2.7 |
42 |
<0.1 |
5.6 |
55 |
<0.2 |
0.4 |
39 |
<0.1 |
<0.1 |
|
|
14.9-15.7 |
<0.1 |
2.1 |
42 |
<0.1 |
6.0 |
54 |
<0.2 |
2.1 |
43 |
<0.1 |
<0.1 |
|
|
VB7 |
Ambient water |
<0.1 |
4.9 |
36 |
<0.1 |
1.2 |
33 |
<0.2 |
31 |
15 |
<0.1 |
<0.1 |
|
0.1-0.9 |
<0.1 |
9.4 |
40 |
<0.1 |
3.1 |
39 |
<0.2 |
36 |
14 |
<0.1 |
<0.1 |
|
|
0.9-1.9 |
<0.1 |
6.7 |
36 |
<0.1 |
2.6 |
35 |
<0.2 |
14 |
27 |
<0.1 |
<0.1 |
|
|
1.9-2.9 |
<0.1 |
7.5 |
32 |
<0.1 |
3.1 |
34 |
<0.2 |
18 |
34 |
<0.1 |
<0.1 |
|
|
4.9-5.9 |
<0.1 |
4.3 |
32 |
<0.1 |
1.1 |
34 |
<0.2 |
21 |
5.0 |
<0.1 |
<0.1 |
|
|
7.9-8.9 |
<0.1 |
4.5 |
32 |
<0.1 |
0.5 |
35 |
<0.2 |
12 |
18 |
<0.1 |
<0.1 |
|
|
10.9-11.9 |
<0.1 |
5.1 |
33 |
<0.1 |
3.3 |
38 |
<0.2 |
24 |
29 |
<0.1 |
<0.1 |
|
|
13.9-14.9 |
<0.1 |
5.7 |
32 |
<0.1 |
1.6 |
33 |
<0.2 |
24 |
17 |
<0.1 |
<0.1 |
|
|
VB8 |
Ambient water |
<0.1 |
1.9 |
40 |
<0.1 |
5.1 |
54 |
<0.2 |
1.6 |
31 |
<0.1 |
<0.1 |
|
0.2-0.9 |
<0.1 |
2.5 |
41 |
<0.1 |
4.8 |
59 |
<0.2 |
3.2 |
26 |
<0.1 |
<0.1 |
|
|
0.9-1.9 |
<0.1 |
2.4 |
42 |
<0.1 |
3.8 |
57 |
<0.2 |
3.4 |
34 |
<0.1 |
<0.1 |
|
|
1.9-2.9 |
<0.1 |
1.6 |
41 |
<0.1 |
4.9 |
53 |
<0.2 |
0.2 |
26 |
<0.1 |
<0.1 |
|
|
4.9-5.9 |
<0.1 |
1.6 |
40 |
<0.1 |
6.5 |
53 |
<0.2 |
0.8 |
38 |
<0.1 |
<0.1 |
|
|
7.9-8.9 |
<0.1 |
2.8 |
42 |
<0.1 |
4.2 |
55 |
<0.2 |
2.0 |
29 |
<0.1 |
<0.1 |
|
|
10.9-11.9 |
<0.1 |
2.8 |
40 |
<0.1 |
5.5 |
61 |
<0.2 |
0.9 |
48 |
<0.1 |
<0.1 |
|
|
12.3-13.3 |
<0.1 |
2.6 |
40 |
<0.1 |
5.6 |
51 |
<0.2 |
<0.4 |
20 |
<0.1 |
<0.1 |
|
|
VB9 |
Ambient water |
<0.1 |
1.3 |
38 |
<0.1 |
3.2 |
57 |
<0.2 |
1.7 |
42 |
<0.1 |
<0.1 |
|
0.5-0.9 |
<0.1 |
1.9 |
42 |
<0.1 |
5.6 |
50 |
<0.2 |
2.6 |
34 |
<0.1 |
<0.1 |
|
|
0.9-1.9 |
<0.1 |
2.3 |
41 |
<0.1 |
4.5 |
54 |
<0.2 |
2.5 |
43 |
<0.1 |
<0.1 |
|
|
1.9-2.9 |
<0.1 |
2.6 |
41 |
<0.1 |
4.3 |
54 |
<0.2 |
3.2 |
39 |
<0.1 |
<0.1 |
|
|
4.9-5.9 |
<0.1 |
2.0 |
41 |
<0.1 |
6.3 |
56 |
<0.2 |
2.3 |
38 |
<0.1 |
<0.1 |
|
|
7.9-8.9 |
<0.1 |
1.0 |
42 |
<0.1 |
4.3 |
57 |
<0.2 |
1.4 |
35 |
<0.1 |
<0.1 |
|
|
10.9-11.9 |
<0.1 |
2.4 |
41 |
<0.1 |
5.7 |
50 |
<0.2 |
1.3 |
28 |
<0.1 |
<0.1 |
|
|
13.9-14.9 |
<0.1 |
2.1 |
41 |
<0.1 |
4.9 |
56 |
<0.2 |
1.3 |
37 |
<0.1 |
<0.1 |
|
|
0.5-0.9 |
<0.1 |
1.2 |
41 |
<0.1 |
4.9 |
57 |
<0.2 |
<0.4 |
44 |
<0.1 |
<0.1 |
|
|
VB11 |
Ambient water |
<0.1 |
0.8 |
40 |
<0.1 |
5.6 |
55 |
<0.2 |
<0.4 |
28 |
<0.1 |
<0.1 |
|
0.9-1.9 |
<0.1 |
1.8 |
40 |
<0.1 |
4.5 |
48 |
<0.2 |
<0.4 |
31 |
<0.1 |
<0.1 |
|
|
1.9-2.9 |
<0.1 |
1.8 |
41 |
<0.1 |
4.5 |
54 |
<0.2 |
<0.4 |
32 |
<0.1 |
<0.1 |
|
|
4.9-5.9 |
<0.1 |
1.8 |
41 |
<0.1 |
5.1 |
53 |
<0.2 |
<0.4 |
42 |
<0.1 |
<0.1 |
|
|
7.9-8.9 |
<0.1 |
1.2 |
43 |
<0.1 |
4.6 |
52 |
<0.2 |
<0.4 |
24 |
<0.1 |
<0.1 |
|
|
10.9-11.9 |
<0.1 |
1.8 |
45 |
<0.1 |
5.2 |
53 |
<0.2 |
<0.4 |
32 |
<0.1 |
<0.1 |
|
|
VB12 |
Ambient water |
<0.1 |
1.9 |
40 |
<0.1 |
3.8 |
57 |
<0.2 |
2.0 |
32 |
<0.1 |
<0.1 |
|
0.1-0.9 |
<0.1 |
1.1 |
42 |
<0.1 |
5.9 |
57 |
<0.2 |
2.7 |
28 |
<0.1 |
<0.1 |
|
|
0.9-1.9 |
<0.1 |
1.2 |
44 |
<0.1 |
4.0 |
57 |
<0.2 |
3.4 |
35 |
<0.1 |
<0.1 |
|
|
1.9-2.9 |
<0.1 |
0.8 |
43 |
<0.1 |
5.3 |
54 |
<0.2 |
2.9 |
29 |
<0.1 |
<0.1 |
|
|
4.9-5.9 |
<0.1 |
1.5 |
42 |
<0.1 |
6.9 |
50 |
<0.2 |
1.2 |
39 |
<0.1 |
<0.1 |
|
|
7.9-8.9 |
<0.1 |
1.7 |
41 |
<0.1 |
5.5 |
62 |
<0.2 |
1.0 |
29 |
<0.1 |
<0.1 |
|
|
10.9-11.9 |
<0.1 |
1.4 |
40 |
<0.1 |
5.5 |
54 |
<0.2 |
0.9 |
43 |
<0.1 |
<0.1 |
|
|
12.6-13.6 |
<0.1 |
2.8 |
41 |
<0.1 |
4.7 |
56 |
<0.2 |
1.8 |
37 |
<0.1 |
<0.1 |
|
|
Reference |
Ambient water |
<0.1 |
2.6 |
31 |
<0.1 |
3.1 |
27 |
<0.2 |
8.8 |
14 |
<0.1 |
<0.1 |
Table
7.14 Elutriate test results (PCBs, TBT,
Chlorinated Pesticides and Nutrients)
|
Sampling
Location |
Sampling
Depth (meter below seabed level) |
Organic-non-PAHs
(μg/L) |
Organo-metallics
(μg/L) |
Chlorinated
Pesticides (μg/L) |
TKN
(mg/L) |
NH3-N
(mg/L) |
NO3-N
(mg/L) |
NO2-N
(mg/L) |
Total
P (mg/L) |
Ortho-P
(mg/L) |
|
Total
PCBs |
TBT |
|||||||||
|
VB1 |
Ambient water |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.15 |
0.08 |
0.01 |
0.17 |
0.036 |
|
0.0-0.9 |
<0.01 |
<0.015 |
<0.05 |
1.5 |
1.2 |
0.49 |
0.01 |
0.39 |
0.029 |
|
|
0.9-1.9 |
<0.01 |
<0.015 |
<0.05 |
2.2 |
1.3 |
1.3 |
0.02 |
0.34 |
0.11 |
|
|
1.9-2.9 |
<0.01 |
<0.015 |
<0.05 |
1.5 |
1.3 |
0.07 |
0.02 |
0.26 |
0.094 |
|
|
4.9-5.9 |
<0.01 |
<0.015 |
<0.05 |
1.2 |
1.1 |
0.15 |
0.02 |
0.32 |
0.088 |
|
|
7.9-8.9 |
<0.01 |
<0.015 |
<0.05 |
0.6 |
0.5 |
0.19 |
0.02 |
0.21 |
0.072 |
|
|
10.9-11.9 |
<0.01 |
<0.015 |
<0.05 |
2.2 |
1.3 |
0.08 |
0.01 |
0.33 |
0.048 |
|
|
13.9-14.9 |
<0.01 |
<0.015 |
<0.05 |
2.4 |
1.7 |
0.7 |
0.02 |
0.23 |
0.022 |
|
|
16.3-17.3 |
<0.01 |
<0.015 |
<0.05 |
4.1 |
3.8 |
0.26 |
0.01 |
0.25 |
0.02 |
|
|
VB2 |
Ambient water |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.03 |
0.03 |
0.23 |
0.026 |
|
0.1-0.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.07 |
0.05 |
<0.01 |
0.21 |
0.026 |
|
|
0.9-1.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.15 |
0.03 |
0.02 |
0.21 |
0.027 |
|
|
1.9-2.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.09 |
0.03 |
0.02 |
0.22 |
0.026 |
|
|
4.9-5.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.04 |
0.02 |
0.20 |
0.027 |
|
|
7.9-8.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.11 |
0.04 |
0.02 |
0.20 |
0.028 |
|
|
10.9-11.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.11 |
0.03 |
0.03 |
0.22 |
0.025 |
|
|
12.0-13.0 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.07 |
0.04 |
0.02 |
0.23 |
0.028 |
|
|
VB3 |
Ambient water |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.19 |
0.02 |
0.14 |
0.036 |
|
0.2-0.9 |
<0.01 |
<0.015 |
<0.05 |
0.8 |
0.7 |
0.05 |
0.02 |
0.24 |
0.041 |
|
|
0.9-1.9 |
<0.01 |
<0.015 |
<0.05 |
2.1 |
2.1 |
0.03 |
0.02 |
0.33 |
0.055 |
|
|
1.9-2.9 |
<0.01 |
<0.015 |
<0.05 |
0.8 |
0.76 |
0.09 |
0.02 |
0.31 |
0.038 |
|
|
4.9-5.9 |
<0.01 |
<0.015 |
<0.05 |
2.1 |
2.0 |
0.08 |
0.02 |
0.33 |
0.061 |
|
|
7.9-8.9 |
<0.01 |
<0.015 |
<0.05 |
2.0 |
2.0 |
0.08 |
0.02 |
0.34 |
0.068 |
|
|
10.9-11.9 |
<0.01 |
<0.015 |
<0.05 |
2.2 |
1.7 |
0.1 |
0.02 |
0.30 |
0.037 |
|
|
13.9-14.9 |
<0.01 |
<0.015 |
<0.05 |
1.6 |
1.4 |
0.07 |
0.02 |
0.31 |
0.04 |
|
|
VB4 |
Ambient water |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.12 |
0.09 |
0.02 |
0.38 |
0.037 |
|
0.0-0.9 |
<0.01 |
<0.015 |
<0.05 |
1.2 |
1.0 |
0.13 |
0.02 |
0.22 |
0.11 |
|
|
0.9-1.9 |
<0.01 |
<0.015 |
<0.05 |
1.3 |
1.2 |
0.11 |
0.02 |
0.20 |
0.074 |
|
|
1.9-2.9 |
<0.01 |
<0.015 |
<0.05 |
0.7 |
0.67 |
0.21 |
0.01 |
0.32 |
0.048 |
|
|
4.9-5.9 |
<0.01 |
<0.015 |
<0.05 |
1.2 |
1.1 |
0.13 |
0.02 |
0.31 |
0.061 |
|
|
7.9-8.9 |
<0.01 |
<0.015 |
<0.05 |
1.6 |
1.5 |
0.1 |
0.01 |
0.21 |
0.071 |
|
|
10.9-11.9 |
<0.01 |
<0.015 |
<0.05 |
3.6 |
2.7 |
0.09 |
0.02 |
0.15 |
0.059 |
|
|
13.9-14.9 |
<0.01 |
<0.015 |
<0.05 |
2.5 |
2.3 |
0.09 |
0.01 |
0.13 |
0.029 |
|
|
15.9-16.7 |
<0.01 |
<0.015 |
<0.05 |
1.7 |
1.4 |
0.18 |
0.01 |
0.13 |
0.035 |
|
|
VB5 |
Ambient water |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.07 |
0.04 |
0.03 |
0.20 |
0.028 |
|
01-0.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.04 |
0.03 |
0.26 |
0.021 |
|
|
0.9-1.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.1 |
0.04 |
0.03 |
0.25 |
0.027 |
|
|
1.9-2.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.04 |
0.03 |
0.26 |
0.025 |
|
|
4.9-5.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.12 |
0.03 |
0.02 |
0.24 |
0.023 |
|
|
7.9-8.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.07 |
0.04 |
0.02 |
0.22 |
0.027 |
|
|
10.9-11.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.1 |
0.03 |
0.02 |
0.26 |
0.026 |
|
|
12.8-13.8 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.03 |
0.02 |
0.26 |
0.024 |
|
|
VB6 |
Ambient water |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.09 |
0.04 |
0.03 |
0.26 |
0.027 |
|
0.1-0.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.04 |
0.02 |
0.25 |
0.028 |
|
|
0.9-1.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.13 |
0.04 |
0.03 |
0.25 |
0.025 |
|
|
1.9-2.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.09 |
0.03 |
0.03 |
0.24 |
0.024 |
|
|
4.9-5.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.1 |
0.04 |
0.03 |
0.25 |
0.027 |
|
|
7.9-8.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.06 |
0.03 |
0.26 |
0.023 |
|
|
10.9-11.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.12 |
0.04 |
0.03 |
0.26 |
0.021 |
|
|
13.9-14.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.1 |
0.03 |
0.02 |
0.33 |
0.022 |
|
|
14.9-15.7 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.07 |
0.03 |
0.03 |
0.22 |
0.024 |
|
|
VB7 |
Ambient water |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.32 |
0.22 |
0.02 |
0.65 |
0.034 |
|
0.1-0.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.37 |
0.75 |
0.04 |
0.14 |
0.11 |
|
|
0.9-1.9 |
<0.01 |
<0.015 |
<0.05 |
1.3 |
1.3 |
0.17 |
0.02 |
0.3 |
0.12 |
|
|
1.9-2.9 |
<0.01 |
<0.015 |
<0.05 |
0.8 |
0.71 |
0.08 |
0.02 |
0.26 |
0.09 |
|
|
4.9-5.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.42 |
0.19 |
0.01 |
0.21 |
0.033 |
|
|
7.9-8.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.11 |
0.77 |
0.01 |
0.12 |
0.034 |
|
|
10.9-11.9 |
<0.01 |
<0.015 |
<0.05 |
3.8 |
3.7 |
0.08 |
0.02 |
0.27 |
0.13 |
|
|
13.9-14.9 |
<0.01 |
<0.015 |
<0.05 |
4.1 |
4.1 |
0.15 |
0.04 |
0.21 |
0.078 |
|
|
VB8 |
Ambient water |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.03 |
0.03 |
0.26 |
0.023 |
|
0.2-0.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.04 |
0.03 |
0.25 |
0.026 |
|
|
0.9-1.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.07 |
0.04 |
0.03 |
0.26 |
0.023 |
|
|
1.9-2.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.1 |
0.03 |
0.02 |
0.24 |
0.024 |
|
|
4.9-5.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.1 |
0.04 |
0.02 |
0.26 |
0.024 |
|
|
7.9-8.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.04 |
0.03 |
0.21 |
0.021 |
|
|
10.9-11.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.06 |
0.03 |
0.03 |
0.26 |
0.022 |
|
|
12.3-13.3 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.07 |
0.03 |
0.03 |
0.26 |
0.024 |
|
|
VB9 |
Ambient water |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.03 |
0.03 |
0.26 |
0.024 |
|
0.5-0.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.06 |
0.04 |
0.03 |
0.24 |
0.026 |
|
|
0.9-1.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.04 |
0.03 |
0.24 |
0.024 |
|
|
1.9-2.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.13 |
0.03 |
0.24 |
0.022 |
|
|
4.9-5.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.07 |
0.04 |
0.03 |
0.23 |
0.024 |
|
|
7.9-8.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.09 |
0.04 |
0.03 |
0.21 |
0.02 |
|
|
10.9-11.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.11 |
0.04 |
0.03 |
0.22 |
0.024 |
|
|
13.9-14.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.03 |
0.03 |
0.22 |
0.025 |
|
|
VB11 |
Ambient water |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.16 |
0.03 |
0.03 |
0.54 |
0.024 |
|
VB11 |
0.5-0.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.13 |
0.04 |
0.03 |
0.48 |
0.025 |
|
0.9-1.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.04 |
0.02 |
0.52 |
0.025 |
|
|
1.9-2.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.22 |
0.03 |
0.02 |
0.53 |
0.025 |
|
|
4.9-5.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.11 |
0.03 |
0.03 |
0.43 |
0.023 |
|
|
7.9-8.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.12 |
0.04 |
0.03 |
0.42 |
0.026 |
|
|
10.9-11.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.06 |
0.03 |
0.03 |
0.38 |
0.023 |
|
|
VB12 |
Ambient water |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.07 |
0.03 |
0.02 |
0.21 |
0.025 |
|
0.1-0.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.1 |
0.03 |
0.02 |
0.22 |
0.022 |
|
|
0.9-1.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.12 |
0.03 |
0.02 |
0.2 |
0.026 |
|
|
1.9-2.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.08 |
0.03 |
0.02 |
0.41 |
0.027 |
|
|
4.9-5.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.1 |
0.03 |
0.03 |
0.44 |
0.026 |
|
|
7.9-8.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.13 |
0.04 |
0.02 |
0.57 |
0.026 |
|
|
10.9-11.9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.25 |
0.03 |
0.02 |
0.56 |
0.023 |
|
|
12.6-13.6 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.1 |
0.03 |
0.02 |
0.56 |
0.024 |
|
|
Reference |
Ambient water |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.06 |
0.03 |
<0.01 |
0.39 |
0.017 |
Table
7.15 Pore water test results for grab samples
(Metals, Metalloid and PAHs)
|
Sampling
Location |
Metals
(μg/L) |
Metalloid
(μg/L) |
Organic-PAHs
(μg/L) |
||||||||
|
Cd |
Cr |
Cu |
Hg |
Ni |
Pb |
Ag |
Zn |
As |
LMW
PAH |
HMW
PAH |
|
|
VB1 |
<0.1 |
4.4 |
34 |
<0.1 |
0.6 |
40 |
<0.2 |
13.2 |
14 |
<0.1 |
<0.1 |
|
VB2 |
<0.1 |
2.1 |
47 |
<0.1 |
4.9 |
57 |
<0.2 |
9.8 |
26 |
<0.1 |
<0.1 |
|
VB3 |
<0.1 |
4.5 |
83 |
<0.1 |
0.2 |
36 |
<0.2 |
22.5 |
8 |
<0.1 |
<0.1 |
|
VB4 |
<0.1 |
4.8 |
42 |
<0.1 |
2.1 |
38 |
<0.2 |
34.3 |
19 |
<0.1 |
<0.1 |
|
VB5 |
<0.1 |
2.7 |
41 |
<0.1 |
5.8 |
50 |
<0.2 |
5.2 |
32 |
<0.1 |
<0.1 |
|
VB6 |
<0.1 |
1.4 |
40 |
<0.1 |
5.4 |
54 |
<0.2 |
0.5 |
38 |
<0.1 |
<0.1 |
|
VB7 |
<0.1 |
4.7 |
33 |
<0.1 |
1.4 |
34 |
<0.2 |
34.4 |
16 |
<0.1 |
<0.1 |
|
VB8 |
<0.1 |
1.1 |
42 |
<0.1 |
5.6 |
56 |
<0.2 |
3.4 |
26 |
<0.1 |
<0.1 |
|
VB9 |
<0.1 |
1.8 |
40 |
<0.1 |
3.9 |
57 |
<0.2 |
3.5 |
32 |
<0.1 |
<0.1 |
|
VB11 |
<0.1 |
1.3 |
40 |
<0.1 |
5.2 |
51 |
<0.2 |
<0.4 |
26 |
<0.1 |
<0.1 |
|
VB12 |
<0.1 |
2.1 |
40 |
<0.1 |
5.2 |
54 |
<0.2 |
3.1 |
35 |
<0.1 |
<0.1 |
|
Reference |
<0.1 |
2.8 |
30 |
<0.1 |
2.1 |
25 |
<0.2 |
6.2 |
14 |
<0.1 |
<0.1 |
Table 7.16 Pore water test results for grab samples
(PCBs, TBT, Chlorinated Pesticides and Nutrients)
|
Sampling
Location |
Organic-non-PAHs
(μg/L) |
Organo-metallics
(μg/L) |
Chlorinated
Pesticides (μg/L) |
TKN
(mg/L) |
NH3-N
(mg/L) |
NO3-N
(mg/L) |
NO2-N
(mg/L) |
Total
P (mg/L) |
Ortho-P
(mg/L) |
|
Total
PCBs |
TBT |
||||||||
|
VB1 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.10 |
2.00 |
0.02 |
0.12 |
0.034 |
|
VB2 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.07 |
0.03 |
0.03 |
0.22 |
0.024 |
|
VB3 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.16 |
0.53 |
0.02 |
0.16 |
0.04 |
|
VB4 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.13 |
0.10 |
0.01 |
0.15 |
0.036 |
|
VB5 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.06 |
0.03 |
0.02 |
0.26 |
0.027 |
|
VB6 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.09 |
0.04 |
0.03 |
0.26 |
0.026 |
|
VB7 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.16 |
0.43 |
0.02 |
0.18 |
0.034 |
|
VB8 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.12 |
0.04 |
0.03 |
0.26 |
0.023 |
|
VB9 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.10 |
0.04 |
0.03 |
0.24 |
0.024 |
|
VB11 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.17 |
0.03 |
0.02 |
0.54 |
0.024 |
|
VB12 |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.06 |
0.03 |
0.02 |
0.24 |
0.025 |
|
Reference |
<0.01 |
<0.015 |
<0.05 |
<0.5 |
0.06 |
0.03 |
<0.01 |
0.38 |
0.026 |
7.6 Classification of Sediment
7.6.1 Based on the chemical and biological test results, the classification of samples according to ETWBTC (Works) No. 34/2002 is summarised in Table 7.17. 10 sediment samples were classified as Category M of which 6 were Category Mp (Type 1 open sea disposal at dedicated sites) and 4 were Category Mf (Type 2 confined marine disposal); 2 Category H sediments were also identified. All remaining sediment samples belong to Category L (Type 1 open sea disposal).
Table 7.17 Classification of sediment
|
Sampling
Location |
Sampling Depth
(meter below seabed level) |
Sediment
Category |
Proposed
Disposal Option (according to
ETWB TC(W) No. 34/2002) |
|||
|
L |
Mp |
Mf |
H |
|||
|
VB1 |
Grab Sample |
# |
|
Type
2 (Confined Marine Disposal) |
||
|
0.0-0.9 |
# |
|
Type
2 (Confined Marine Disposal) |
|||
|
0.9-1.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
1.9-2.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
4.9-5.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
7.9-8.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
10.9-11.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
13.9-14.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
16.3-17.3 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
VB2 |
Grab Sample |
# |
|
|
Type 1 (Open Sea Disposal) |
|
|
0.1-0.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
0.9-1.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
1.9-2.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
4.9-5.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
7.9-8.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
10.9-11.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
12.0-13.0 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
VB3 |
Grab Sample |
# |
|
|
Type 1 (Open Sea Disposal) |
|
|
0.2-0.9 |
|
# |
Type
2 (Confined Marine Disposal) |
|||
|
0.9-1.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
1.9-2.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
4.9-5.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
7.9-8.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
10.9-11.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
13.9-14.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
VB4 |
Grab Sample |
# |
|
|
Type
1# Open Sea Disposal (Dedicated Sites) |
|
|
0.0-0.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
0.9-1.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
1.9-2.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
4.9-5.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
VB4 |
7.9-8.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
|
|
10.9-11.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
13.9-14.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
15.9-16.7 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
VB5 |
Grab Sample |
# |
|
|
Type
1# Open Sea Disposal (Dedicated Sites) |
|
|
01-0.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
0.9-1.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
1.9-2.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
4.9-5.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
7.9-8.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
10.9-11.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
12.8-13.8 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
VB6 |
Grab Sample |
# |
|
Type
2 (Confined Marine Disposal) |
||
|
0.1-0.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
0.9-1.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
1.9-2.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
4.9-5.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
7.9-8.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
10.9-11.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
13.9-14.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
14.9-15.7 |
# |
|
Type
2 (Confined Marine Disposal) |
|||
|
VB7 |
Grab Sample |
# |
|
|
Type
1# Open Sea Disposal (Dedicated Sites) |
|
|
0.1-0.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
0.9-1.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
1.9-2.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
4.9-5.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
7.9-8.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
10.9-11.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
13.9-14.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
VB8 |
Grab Sample |
# |
|
|
Type 1 (Open Sea Disposal) |
|
|
0.2-0.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
0.9-1.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
1.9-2.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
4.9-5.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
7.9-8.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
10.9-11.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
12.3-13.3 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
VB9 |
Grab Sample |
# |
|
|
Type
1# Open Sea Disposal (Dedicated Sites) |
|
|
0.5-0.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
VB9 |
0.9-1.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
|
|
1.9-2.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
4.9-5.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
7.9-8.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
10.9-11.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
13.9-14.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
VB11 |
Grab Sample |
# |
|
|
Type
1# Open Sea Disposal (Dedicated Sites) |
|
|
0.5-0.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
0.9-1.9 |
|
# |
Type
2 (Confined Marine Disposal) |
|||
|
1.9-2.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
4.9-5.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
7.9-8.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
10.9-11.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
VB12 |
Grab Sample |
# |
|
|
Type
1# Open Sea Disposal (Dedicated Sites) |
|
|
0.1-0.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
0.9-1.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
1.9-2.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
4.9-5.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
7.9-8.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
10.9-11.9 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
|
12.6-13.6 |
# |
|
|
Type 1 (Open Sea Disposal) |
||
7.6.2 The classification of sediment samples given in Table 7.17 above was used to estimate the quantities of different category of marine deposit to be excavated and disposed from CBL. This information is vital to determine the disposal options of excavated marine deposit in accordance with ETWB TC(W) No. 34/2002.
Estimation of quantities of excavated marine deposit
7.6.3 In accordance with the proposed CBL alignment and preliminary bridge design, there are total 12 piers along the alignment. The four Western Approach Piers are numbered 1 to 4 and the six Eastern Approach Piers are numbered 5 to 10. The two piers of the main bridge are named as Pylon A and Pylon B. Among the 11 sediment sampling locations, VB3 to VB7 are located along the recommended alignment. Therefore, the testing results of these sampling locations are applied to each pier as illustrated in Drawing no. 209506/EIA/SQ/003 based on the proximity.
7.6.4 Classification of sediment samples given in Table 7.17 and the design details of the foundations at each pier and pylon, together with the data from geotechnical investigations are used to estimate the quantities of different category of marine deposit to be excavated and disposed. A summary of the estimation is provided in Table 7.18. Detailed calculations are given in Appendix 7.3. It is estimated that a total of approximately 4,300m3 marine deposit is required to be excavated. Amongst the excavated volume, approximately 96.7% is Category L sediment. Category Mp, Mf, and H sediments contribute to about 3.3% of the total volume.
Table 7.18 Estimated quantities of different
categories of excavated marine deposit
|
Sampling
Location |
Pier |
Estimated
quantities of excavated marine sediment (m3) |
Total
estimated quantities of excavated marine sediment (m3) |
||||
|
Category
L |
Category
Mp |
Category
Mf |
Category
H |
||||
|
Western
Approach Piers |
|||||||
|
VB3 |
1 |
254.5 |
0.0 |
0.0 |
9.4 |
263.9 |
|
|
VB3 |
2 |
254.5 |
0.0 |
0.0 |
9.4 |
263.9 |
|
|
VB3 |
3 |
273.3 |
0.0 |
0.0 |
9.4 |
282.7 |
|
|
VB4 |
4 |
256.4 |
7.5 |
0.0 |
0.0 |
263.9 |
|
|
Main
Bridge Piers |
|||||||
|
VB4 |
Pylon
A |
688.0 |
18.8 |
0.0 |
0.0 |
706.9 |
|
|
VB5 |
Pylon
B |
735.1 |
18.8 |
0.0 |
0.0 |
754.0 |
|
|
Eastern
Approach Piers |
|||||||
|
VB6 |
5 |
256.4 |
0.0 |
7.5 |
0.0 |
263.9 |
|
|
VB6 |
6 |
256.4 |
0.0 |
7.5 |
0.0 |
263.9 |
|
|
VB6 |
7 |
273.3 |
0.0 |
28.3 |
0.0 |
301.6 |
|
|
VB7 |
8 |
312.9 |
7.5 |
0.0 |
0.0 |
320.4 |
|
|
VB7 |
9 |
284.6 |
7.5 |
0.0 |
0.0 |
292.2 |
|
|
VB7 |
10 |
275.2 |
7.5 |
0.0 |
0.0 |
282.7 |
|
|
Total
estimated quantities of each category (m3) |
4120.5 |
67.9 |
43.4 |
28.3 |
4260.0 |
||
|
Total
estimated quantities of each disposal options to the nearest digit
(percentage,%) |
Type
1 |
Type
1# |
Type
2 |
||||
|
4120.5 (96.7) |
67.9 (1.6) |
71.7 (1.7) |
4260.0 (100.0) |
||||
Note:
1.
Type 1
- Open sea disposal (applicable to Category L).
2.
Type 1#
- Open sea disposal (Dedicated sites) (applicable to Category Mp).
3.
Type 2
- Confined marine disposal (applicable to Category Mf & H).
7.7.1 This section reviewed the sediment quality data and summarised the findings of the site investigation for sediment quality in relation to the proposed alignment of CBL. The sediment was classified in accordance with ETWB TC(W) No. 34/2002. The corresponding disposal methods were also proposed.
7.7.2 Classification of the sediment samples based on the chemical and biological test results, estimation of the quantities of different Categories of marine deposit to be excavated from the marine works of CBL and the corresponding disposal options are provided in this section.
7.7.3 Sediment quality been assessed according to the requirements of Annex 15, Guidelines for Assessment of Waste Management Implications, of the TM-EIAO. It is concluded that in respect of the marine sediment to be excavated and disposed at sea during the construction of the CBL, Annex 7, Criteria for Evaluating Waste Management Implications, of the TM-EIAO would be complied with.