Agreement No. CE 4/2009 (EP)
Environmental Monitoring and Audit
for Contaminated Mud Pit at Sha Chau (2009-2013) - Investigation

20th MONTHLY PROGRESS REPORT FOR CONTAMINATED MUD PITS AT SHA CHAU - February 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 HKSARs 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 and 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.

1.2                                      Reporting Period

This Monthly Progress Report covers the monitoring period of February 2011.

1.3                                      Details of Sampling and Laboratory Testing Activities

The following monitoring activities have been undertaken for CMP IV and CMP V in February 2011:

CMP IV

         Water Column Profiling was conducted on 9 February;

         Routine Water Quality Monitoring was conducted on 10 February;

         Water Quality Monitoring during Capping was conducted on 11 February; and

         Demersal Trawling was conducted on 16-17 February.

CMP V

         Impact Water Quality Monitoring during Dredging Operations was conducted on 15 February.

A summary of field activities are presented in Annex A.

1.4                                      Details of Outstanding Sampling and / or Analysis

No outstanding sampling and laboratory analysis remained from February 2011.

1.5                                      Brief Discussion of the Monitoring Results

Results of Impact Water Quality Monitoring during Dredging Operations for February 2011 are presented for CMP V. Detailed results will be discussed in the relevant Quarterly Reports.

1.5.1                                CMP V

Impact Water Quality Monitoring during Dredging Operations of CMP V February 2011

Impact Water Quality Monitoring during Dredging Operations of CMP V was conducted on 15 February 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

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.

1.7                                      Study Programme

A summary of the Study programme is presented in Annex C.


 



([1]) ERM (2009) Baseline Monitoring Report. Environmental Monitoring and Audit for Contaminated Mud Pit at Sha Chau (2009-2013) Investigation. Agreement No. CE 4/2009(EP). Submitted to EPD in September 2009.