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

7th MONTHLY PROGRESS REPORT FOR CONTAMINATED MUD PITS AT SHA CHAU - January 2010

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 2010.  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 Va.  The environmental monitoring and audit (EM&A) programme for the CMPs at the East of Sha Chau area presently covers disposal operations at CMP IVc and dredging operations at CMP V.

1.2                                      Reporting Period

This Monthly Progress Report covers the monitoring period of January 2010.

1.3                                      Details of Sampling and Laboratory Testing Activities

Field sampling activities conducted in this monthly period for CMP IVc are listed below:

·           Demersal Trawling was conducted on 14 and 15 January 2010; and,

·           Water Column Profiling was conducted on 18 January 2010.

For CMP V, sampling for Water Column Profiling and Impact Monitoring during Dredging Operations were conducted on 19 and 20 January 2010, respectively.  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 on 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 IV

 

 

Water Sampling and Chemical Analysis

a) Water Column Profiling

December’s sampling:

21 January 2010

 

 

January’s sampling:

27 January 2010

CMP V

 

 

Water Sampling and Chemical Analysis

a) Water Column Profiling

January’s sampling:

28 January 2010

 

b) Impact Monitoring during Dredging Operations

January’s sampling:

29 January 2010

1.4                                      Details of Outstanding Sampling and / or Analysis

No outstanding sampling remained from January 2010.  Data for Tissue/Whole Body Contaminant Testing remained outstanding from the Contractor.

1.5                                      Brief Discussion of the Monitoring Results

Results of Water Column Profiling for December 2009 and January 2010 are presented for CMP IV.  Monitoring results presented for CMP V include Water Column Profiling and Impact Monitoring during Dredging Operations for January 2010.  Detailed results will be discussed in the relevant Quarterly Reports.

1.5.1                                CMP IV

Water Column Profiling for CMP IV in December 2009

Results of Water Column Profiling for December 2009 show that levels of salinity, pH and dissolved oxygen (DO) compiled with the water quality objectives (WQOs) at both Upstream and Downstream stations (Figures 2 to 4 of Annex B).  Levels of total suspended solids (TSS) exceeded the WQO at the Upstream station and was within compliance limits for the Downstream station (Figure 1 of Annex B). 

Water Column Profiling for CMP IV in January 2010

Results of Water Column Profiling for January 2010 show that levels of salinity, pH and DO compiled with the WQOs at both Upstream and Downstream stations (Figures 6 to 8 of Annex B).  Levels of TSS complied with the WQO at both Upstream and Downstream stations (Figure 5 of Annex B). 

 

1.5.2                                CMP V

Water Column Profiling for CMP V during January 2010

Results of Water Column Profiling for January 2010 show that levels of salinity, pH and DO compiled with the WQOs at both Upstream and Downstream stations (Figures 10 to 12 of Annex B).  Levels of TSS complied with the WQO at both Upstream and Downstream stations (Figure 9 of Annex B). 

Impact Monitoring during Dredging Operations of CMP V – January 2010

Impact Monitoring during Dredging Operations of CMP V was conducted on 20 January 2010.  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 and water samples were taken from three water depth levels of the water column which were surface (1m below sea surface), mid-depth and bottom (1m above the seabed).

Monitoring results are presented in Figures 13 to 16 of Annex B.  Levels of DO, depth-average Turbidity and TSS complied with the Action and Limit Levels set in the Baseline Monitoring Report ([1]) (Tables B1 and B2 of Annex B). 

1.6                                      Activities Scheduled for the Next Month

The following monitoring activities will be conducted in the next monthly period of February 2010:

·           Demersal Trawling for CMP IV;

·           Routine Water Column Profiling for CMP IV;

·           Water Quality Monitoring during Capping of CMP IV;

·           Impact Monitoring during Dredging Operations for CMP V; and,

·           Water Column Profiling for both CMP IV and CMP V.

The sampling schedule is presented in Annex A. 

1.7                                      Study Programme

A summary of 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.