Agreement No. CE 4/2009 (EP)
Environmental Monitoring and Audit
for Contaminated Mud Pit at Sha Chau
(2009-2013) - Investigation
25th MONTHLY PROGRESS REPORT FOR CONTAMINATED MUD PITS AT SHA
CHAU July 2011
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. CMP IVc is
presently in operation for backfilling by contaminated mud and is anticipated
to reach its capacity in 2011. 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. Dredging operations were
completed for the construction of CMP Va-b and are
now taking place to construct CMP Vc. 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 July 2011.
1.3
Details of Sampling and
Laboratory Testing Activities
For CMP IV, Water Column Profiling
was conducted on 22 July and Demersal Trawling
was conducted on 27-28 July 2011. For CMP V, sampling for Impact Water Quality Monitoring during Dredging Operations was conducted on 21 July
2011. A summary of field activities are presented in Annex A.
A summary of laboratory analysis results submitted by the Contractor in
this reporting month is presented in Table
1.1.
Table 1.1 Summary
of laboratory analysis results submitted by the Contractor during the reporting
month
|
Key
Task |
Monitoring
Component |
Results Received from the Contractor |
|
CMP V |
|
|
|
Impact
Monitoring during Dredging Operations |
Water Quality |
June 2011 sampling: 8
July 2011 |
|
|
|
|
1.4
Details of Outstanding
Sampling and / or Analysis
No outstanding sampling and laboratory analysis remained from July 2011.
1.5
Brief Discussion of the
Monitoring Results
Results of Impact Water Quality Monitoring
during Dredging Operations for July 2011 are presented for CMP V. Detailed results will be discussed in the 9th Quarterly Report.
1.5.1
CMP V
Impact Water Quality Monitoring during Dredging
Operations of CMP V – July 2011
Impact
Water Quality Monitoring during Dredging Operations of CMP V was conducted
on 21 July 2011. 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 V. 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]). Therefore,
there appears to be no evidence of any unacceptable adverse water quality
impacts arising from the dredging operations of CMP V at ESC.
1.6
Activities Scheduled for the
Next Month
The following monitoring activities will be conducted in the next monthly period of August
2011:
·
Pit-Specific Sediment Chemistry for CMP IV;
·
Cumulative Impact Sediment Chemistry for CMP IV;
·
Sediment Toxicity Tests for CMP IV;
·
Benthic Recolonisation
Studies for CMP IV;
·
Demersal Trawling for CMP IV;
·
Water Quality Monitoring during Capping for CMP IV;
·
Routine Water Quality Monitoring for CMP IV;
·
Water Column Profiling for CMP IV; and,
·
Impact Water Quality Monitoring during Dredging
Operations for CMP V.
The sampling schedule is presented in Annex A.
1.7
Study Programme
A summary of the Study programme is presented in Annex C.