Agreement No. CE 4/2009 (EP)
Environmental Monitoring and Audit
for Contaminated Mud Pit at Sha Chau (2009-2013) - Investigation
17th MONTHLY PROGRESS REPORT FOR CONTAMINATED MUD PITS AT SHA CHAU - November 2010
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 are now taking place to construct CMP Vb. 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 Vb.
This Monthly Progress Report covers the monitoring period of November 2010.
Sediment Quality Monitoring was conducted on 23 November in this monthly period for CMP IVc. For CMP V, sampling for Impact Water Quality Monitoring during Dredging Operations was conducted on 9, 11 and 13 November. A summary of field activities are presented in Annex A.
No outstanding sampling and laboratory analysis remained from November 2010.
Results of Impact Water Quality Monitoring during Dredging Operations for November 2010 are presented for CMP V. Detailed results will be discussed in the relevant Quarterly Reports.
Impact Water Quality Monitoring during Dredging Operations of CMP V was conducted on 9, 11 and 13 November 2010. On each 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 (). Therefore, there appears to be no evidence of any unacceptable adverse water quality impacts arising from the dredging operations of CMP V at ESC.
The following monitoring events are scheduled for the CMPs:
· Pit Specific Sediment Chemistry Monitoring;
· Cumulative Impact Sediment Chemistry Monitoring;
· Sediment Toxicity Monitoring;
· Water Column Profiling;
· Water Quality Monitoring during Capping;
· Benthic Recolonisation Monitoring; and
· Demersal Trawling.
Impact Water Quality Monitoring during Dredging will be undertaken for CMP V in the next monitoring month.
The sampling schedule is presented in Annex A.
A summary of the Study programme is presented in Annex C.