Agreement No. CE 23/2012 (EP)
Environmental Monitoring and Audit
for Contaminated Mud Pits to the South of The Brothers
and at East Sha Chau (2012-2017) - Investigation
29th MONTHLY PROGRESS REPORT FOR January 2015
Since early 1990s, contaminated sediment () arising from various
construction works (e.g. dredging and reclamation projects) in Hong Kong has been disposed of at a series of seabed pits
at East of Sha Chau
(ESC). In late 2008, a review indicated
that the existing and planned facilities at ESC would not be able to meet the
disposal demand after 2012. In order to
meet this demand, the Hong Kong Special Administrative Region Government
(HKSARG) decided to implement a new contained aquatic disposal (CAD) () facility at the South
of The Brothers (SB CMPs) which had been under
consideration for a number of years.
The environmental acceptability of the construction and
operation of the Project had been confirmed by findings of the associated
Environmental Impact Assessment (EIA) study completed in 2005 under Agreement No. CE 12/2002(EP) ().
The Director of Environmental Protection (DEP) approved this EIA report
under the Environmental
Impact Assessment Ordinance (Cap. 499) (EIAO) in September 2005 (EIA Register No.: AEIAR-089/2005).
In accordance with the EIA recommendation, prior to
commencement of construction works for the SB CMPs,
the Civil Engineering and Development Department (CEDD) undertook a detailed
review and update of the EIA findings for the SB site (). Findings of the EIA review undertaken in
2009/ 2010 confirmed that the construction and operation of the SB site had
been predicted to be environmentally acceptable.
(EP-312/2008/A and EP-427/2011A) were issued by the Environmental
Protection Department (EPD) to the CEDD, the Permit Holder, on 28 November 2008
for ESC CMP V and on 23 December 2011 for SB CMPs,
respectively. Under the requirements of
the EPs, an Environmental
Monitoring and Audit (EM&A) programme as set out in the EM&A Manuals ()
() is required to be
implemented for the CMPs.
The present EM&A programme under Agreement No. CE 23/2012 (EP) covers the dredging,
disposal and capping operations of the SB CMPs as well as ESC CMPs. Detailed works schedule for both CMPs is shown in Figure 1.1. In January 2015, the following
works were being undertaken at the CMPs:
· Capping operations at ESC CMP Va
· Disposal of contaminated mud at SB CMP 2; and
· Capping operations at SB CMP 1.
Figure 1.1 Works
Schedule for ESC CMPs and SB CMPs
Monthly Progress Report covers the EM&A activities for
the reporting month of January 2015.
Details of Sampling and
Laboratory Testing Activities
No monitoring activities have
been undertaken for ESC CMPs in January 2015.
The following monitoring
activities have been undertaken for SB CMPs in January 2015:
Column Profiling of CMP 2 was undertaken on 14 January 2015;
Water Quality Monitoring of CMP 2 was
undertaken on 15 January 2015;
Specific Sediment Chemistry of CMP 2 was undertaken on 16 January 2015; and
· Demersal Trawling for SB CMP was undertaken on 15 and 16 January
Details of Outstanding
Sampling and/or Analysis
No outstanding sampling
January 2015. The following
laboratory analyses were still in progress during the preparation of this
monthly report and hence are not presented in this monthly report:
· Laboratory analyses of sediment samples collected
for Pit Specific Sediment Chemistry in
· Laboratory analyses of water samples collected for Routine Water Quality Monitoring in
January 2015; and
· Taxonomic identification of fishery resources
collected during Demersal Trawling for SB CMP in January 2015.
A summary of field activities
conducted are presented in Annex A.
Brief Discussion of the
Monitoring Results for SB CMPs
A brief discussion
of the monitoring results of the following activities for SB CMPs is presented in this 29th Monthly Progress Report:
Specific Sediment Chemistry of CMP 2 conducted in December 2014;
· In-situ measurements of Routine
Water Quality Monitoring conducted in January 2015;
Column Profiling conducted
· Laboratory analyses of samples collected for Water Quality Monitoring during Capping of
CMP 1 conducted in December 2014.
Sediment Chemistry of CMP 2 – December 2014
Monitoring locations for Pit Specific
Sediment Chemistry for CMP 2 are shown in Figure 1.2. A total of six (6) monitoring stations were
sampled in December 2014.
concentrations of all inorganic contaminants were
lower than the Lower Chemical Exceedance Level (LCEL)
at all stations in December 2014
(Figures 1 and 2 of
For organic contaminants, the concentrations of Total Organic Carbon (TOC) were
similar amongst stations in December 2014 (Figure 3 of Annex
B). Tributyltins (TBTs) were
observed to be higher at Active Pit station SB-NPBB in December 2014 (Figures 4 of Annex B). High
Molecular Weight Polycyclic Aromatic Hydrocarbons (MW PAHs)
and Low MW PAHs were below the limit of reporting at
all stations in December 2014 (Figures 5 of Annex
B). Total Dichloro-Diphenyl-Trichloroethane (DDT),
4,4’-Dichloro-Diphenyl-Dichloroethylene (4,4’-DDE) and Total Polychlorinated
Biphenyls (PCBs) were recorded below the limit of reporting at all stations in
December 2014 as well.
Higher TBTs concentrations were recorded within the Active Pit
stations only which were receiving contaminated mud during the reporting month,
as such, there is no
evidence indicating any dispersal of contaminants from CMP 2 (Active Pit) to nearby
Overall, there is no evidence indicating any
unacceptable environmental impacts to sediment quality as a result of the
contaminated mud disposal operations at CMP 2 in December 2014.
Quality Monitoring of
SB CMP 2 – January 2015
The monitoring results
for the Routine Water Quality Monitoring
conducted in January
2015 in the dry season
have been assessed for compliance with the Water Quality Objectives (WQOs) set by EPD. This
consists of a review of the EPD routine water quality monitoring data for the
dry season period (November to March) of 2004 - 2013
from stations in the Northwestern Water Control Zone,
where the CMPs are located. For Salinity, the averaged value obtained
from the Reference stations was used for the basis as the WQO. Levels of DO, Turbidity and
SS were also assessed for compliance with the Action and Limit Levels (see
C1 of Annex C for details). The monitoring results are shown in Figures 6-10
of Annex B and Table
C2 of Annex C. A total of fourteen (14)
monitoring stations were sampled in January 2015 as shown in Figure 1.3.
results for January 2015
indicated that the levels of pH, DO and Salinity complied with the WQOs at all stations (Impact, Intermediate, Reference and
Water Sensitive Receiver stations) in January 2015 (Figures 6-9 of Annex B).
The levels of DO and Turbidity
complied with the Action and Limit Levels at all stations (Figures 8 and
of Annex B; Table C1 of Annex C).
Overall, results of the Routine Water
Quality Monitoring indicated that the disposal operation at CMP 1 did not
appear to cause any unacceptable impacts in water quality in January 2015.
Profiling of CMP 2 – January 2015
Water Column Profiling was
undertaken at a total of two sampling stations (Upstream and Downstream
stations) on 14
2015. The water quality
monitoring results have been assessed for compliance with the WQO (see Section 1.5.9 for
monitoring results were also compared with the Action and
set in Baseline Monitoring Report (see Table C1 of Annex C for
Analyses of results for January
2015 indicated that levels of Salinity, DO
and pH complied with the WQOs at both Downstream and
Upstream stations (Table C3 of Annex C). DO and Turbidity levels at all stations complied with
the Action and Limit Levels (Tables C1 and C3 of Annex C).
Measurements for SS
Analyses of results for January
2015 indicated that the SS levels
at both Upstream and Downstream stations complied with the WQO. SS levels at all stations also complied with the
Action and Limit Levels (Tables C1 and C3 of Annex C).
Overall, the monitoring results
indicated that the mud disposal operation at CMP 2 did not appear to cause any unacceptable
impacts in water quality during this reporting period.
Monitoring during Capping Operations of CMP 1– December 2014
The monitoring results obtained
during December 2014 sampling in the dry season have been assessed for
compliance with the WQOs (see Section 1.5.9 for details). A total of fourteen (14) monitoring stations
were sampled in December 2014 as shown in Figure 1.3. Graphical presentation of
the monitoring results is provided in Annex
Concentrations of SS complied
with the WQO at all stations in December 2014 (Figure 11 of
For nutrients, concentrations of
Ammonia (NH3) and
5-day Biochemical Oxygen Demand (BOD5) were similar
amongst all stations (Figures 12 and 14 of Annex B). Total Inorganic Nitrogen (TIN) at all
stations complied with the WQO of 0.5 mg/L in December 2014 (Figure 13
of Annex B).
analysis will be undertaken in the quarterly report to investigate whether the
capping operations at CMP 1 is causing any unacceptable impacts in
water quality of the area.
Activities Scheduled for the
The following monitoring activities
will be conducted in the next monthly period of February
2015 for SB CMPs:
Specific Sediment Chemistry of CMP 2;
· Cumulative Impact
Sediment Chemistry of SB CMP;
· Sediment Toxicity
Tests of CMP 2;
· Tissue / Whole
Body Analysis of Trawled Samples for SB CMP;
· Demersal Trawling for CMP 2;
Water Quality Monitoring for CMP 2;
Column Profiling of CMP 2; and
Quality Monitoring during Capping Operations of CMP 1.
Water Quality Monitoring during Capping Operations of ESC CMPs will be conducted in the next monthly period of
February 2015 for ESC CMPs.
The sampling schedule is presented
in Annex A.
A summary of the Study programme is
presented in Annex D.