Agreement No. CE 4/2009 (EP)
Environmental Monitoring and Audit
for Contaminated Mud Pit at Sha Chau
(2009-2013) - Investigation
31st MONTHLY PROGRESS REPORT FOR CONTAMINATED MUD PITS AT SHA
CHAU January 2012
1.1
Background
Since 1992, the East of Sha Chau area has been the site of a series of dredged
contaminated mud pits (CMPs) designed to provide
confined marine disposal capacity for contaminated mud arising from the HKSAR’s dredging and reclamation projects. In January 2012, CMP IVc was in operation for
backfilling by contaminated mud and was anticipated to reach its capacity in
February 2012. A series of four newly constructed seabed pits at the East of Sha Chau area, CMP Va-d, will be provided for the disposal of contaminated mud
after CMP IVc is full. The dredging of CMPs Va
and Vb had been completed and that of CMP Vc was in progress. The environmental monitoring and audit (EM&A)
programme for the CMPs at the East of Sha Chau area presently covers
disposal and capping operations at CMP IV and dredging operations at CMP Vc.
1.2
Reporting
Period
This Monthly Progress Report
covers the monitoring period of January 2012.
1.3
Details
of Sampling and Laboratory Testing Activities
The following monitoring
activities have been undertaken for CMP IVc in January
2012:
·
Demersal Trawling was conducted on 1 and 2 January; and
·
Water Column Profiling was conducted on 16 January.
For CMP Vc,
sampling for Impact Water Quality Monitoring
during Dredging Operations was conducted on 12
January 2012. A summary of field activities is presented in Annex A.
A summary of monitoring data
submitted by the Contractor for this reporting month is presented in Table 1.1.
Table 1.1 Summary
of monitoring data submitted by the Contractor for the reporting month
|
Key Task |
Monitoring Component |
Date of Results Received from the Contractor |
|
CMP Vc |
|
|
|
Impact
Monitoring during Dredging Operations |
Water Quality |
1 March 2012 |
|
|
|
|
1.4
Details
of Outstanding Sampling and / or Analysis
No outstanding sampling and laboratory analysis remained from January
2012
1.5
Brief
Discussion of the Monitoring Results
1.5.1
CMP V
Impact Water Quality
Monitoring during Dredging Operations of CMP V – January 2012
Impact
Water Quality Monitoring during Dredging Operations of CMP V was conducted
on 12 January 2012. On the survey day, sampling was
conducted during both mid-ebb and mid-flood tides at two Reference (Upstream)
stations upstream and five Impact (Downstream) stations downstream of the
dredging operations at CMP Vc (Figure 1.1). Monitoring was also conducted at the Ma Wan
station. At each station, in-situ measurements of water quality
parameters as well as water samples were taken from three depths in the water
column (ie surface: 1 m below sea surface, mid-depth
and bottom: 1 m above the seabed).
Monitoring results are
presented in Table B1 of Annex B. Levels
of Dissolved Oxygen (DO), Turbidity and Total Suspended Solids (TSS) complied
with the Action and Limit Levels set in the Baseline
Monitoring Report ([1]). Overall,
the results indicated that the dredging operations at CMP Vc
did not appear to cause any unacceptable deterioration in water quality during
this reporting period.
Therefore, no further
mitigation measures, except for those recommended in the Environmental Permit (EP-312/2008), are considered required for
the dredging operations of CMP Vc.
1.6
Activities
Scheduled for the Next Month
The following monitoring programmes will be
conducted in the next monthly period of February 2012:
CMP IV
·
Water Quality Monitoring during Capping for CMP IVc;
·
Tissue/ Whole Body Sampling for CMP IVc; and
·
Demersal Trawling for CMP IVc.
CMP V
·
Cumulative Impact Sediment Chemistry for CMP Va;
·
Sediment Toxicity Tests for CMP Va;
·
Routine Water Quality Monitoring for CMP Va;
·
Pit Specific Sediment Chemistry for CMP Va;
·
Water Column Profiling for CMP Vc;
and
·
Impact Water Quality Monitoring during Dredging
Operations for CMP Vc.
The sampling schedule is presented in Annex A.
1.7
Study
Programme
A summary of the Study Programme is presented in Annex C.