12 Land Contamination Assessment
This chapter presents the findings of the land contamination assessment of the impacts from the proposed Stabling Sidings at Hung Hom Freight Yard. The Project covers the modification works of Hung Hom Station (HUH) and construction of Kai Tak Station (KAT) and Diamond Hill Station (DIH) based on the HHS option during the construction phase.
A Contamination Assessment Plan (CAP) has been
prepared and was approved by EPD on 11 October 2011 (as attached in Appendix 12.1) to
identify potential land contamination sites within the intrusive works area
under this Project and. Under the CAP, a review of previous land contamination
studies within the Project boundary has been conducted. Site investigations
results within the project boundary were found under two approved Contamination
Assessment Reports (CARs) for SCL (TAW-HUH) and SCL (MKK-HUH) and findings of
the review are summarized in Section
12.3. The CARs for SCL (TAW-HUH) and SCL (MKK-HUH) referred in this Project
had been carried out under Guidance Notes
for Investigation Remediation of Contaminated Sites of Petrol Filling Stations,
Boatyards, and Car Repairing/Dismantling Workshops and were endorsed by
EPD. For the purpose of land contamination study under this project, the CARs
have also been reviewed and the findings adopted in this Project are consistent
with the requirements stipulated in the PG.
Legislation
and non-statutory guidance for carrying out the land contamination assessment
is provided in the following:
·
Technical Memorandum on Environmental Impact
Assessment Process (TM-EIA);
· Practice Guide (PG) for Investigation and Remediation of Contaminated Land
· Guidance Notes for Contaminated Land Assessment and Remediation; and
·
Guidance Manual for Use of Risk-Based Remediation
Goals (RBRGs) for Contaminated Land Management, EPD.
As discussed in Section 12.1, the findings of site investigation for SCL (MKK-HUH) and SCL (TAW-HUH) have been reviewed. According to the CAR for SCL (MKK-HUH) and SCL (TAW-HUH), a total of 24 boreholes and 8 trial pits were drilled for soil and groundwater sampling at Hung Hom and Diamond Hill within or in close proximity to current Study Area for the 240 soil and 22 groundwater samples collected. No exceedance of RBRG (industrial) level was found and the summary of SI works and laboratory testing results are presented in Table 12.1 below.
For Kai Tak Works Site, the CAR of SCL (TAW-HUH) indicated that the de-contamination works within North Apron Area of Kai Tak Airport was completed under Environmental Permit EP007/1998 and thus further site investigation of contaminated soils/ groundwater for that KAT Works Site would not be required.
Table 12.1
Summary of SI Works and
laboratory results
|
Study Area of SCL (HHS) |
Drillhole Reference |
Sampling Method |
No. of Sample Tested |
Compliance to
Industrial RBRGs |
|
|
Soil |
Groundwater |
||||
|
2209/SCL/EDH249(P) |
Borehole |
10 |
1 |
All sample results indicated compliance |
|
|
2209/SCL/ETT103 |
Trial Pit |
3 |
0 |
||
|
11203/SCL/EB121 |
Borehole |
3 |
0 |
||
|
11202/SCL/EDH138 |
Borehole |
10 |
1 |
||
|
11202/SCL/EDH139 |
Borehole |
14 |
1 |
||
|
11202/SCL/EDH140 |
Borehole |
14 |
1 |
||
|
11202/SCL/EDH141 |
Borehole |
16 |
1 |
||
|
11202/SCL/EDH142 |
Trial Pit |
3 |
0 |
||
|
11202/SCL/EDH143 |
Borehole |
13 |
1 |
||
|
11202/SCL/EDH144 |
Borehole |
13 |
1 |
||
|
11203/SCL/EB146 |
Borehole |
5 |
1 |
||
|
2209/SCL/ETT165 |
Trial Pit |
3 |
0 |
||
|
11203/SCL/EB140 |
Borehole |
5 |
1 |
||
|
11203/SCL/EB141 |
Borehole |
5 |
1 |
||
|
2209/SCL/ETT102 |
Trial Pit |
3 |
0 |
||
|
2209/SCL/EDH244 |
Borehole |
11 |
1 |
||
|
11202/SCL/ETP027 |
Trial Pit |
3 |
0 |
||
|
11202/SCL/ETP012 |
Borehole |
11 |
1 |
||
|
11202/SCL/ETP042 |
Trial Pit |
3 |
0 |
||
|
11202/SCL/ETP043 |
Trial Pit |
3 |
0 |
||
|
11202/SCL/ETP044 |
Trial Pit |
3 |
0 |
||
|
2209/SCL/EDH231 |
Borehole |
7 |
1 |
||
|
2209/SCL/EDH229(P) |
Borehole |
6 |
1 |
||
|
2209/SCL/EDH124(P) |
Borehole |
5 |
0 |
||
|
2209/SCL/EDH257 |
Borehole |
6 |
1 |
||
|
Diamond Hill |
2209/SCL/EDH036 |
Borehole |
11 |
1 |
|
|
2209/SCL/EDH037(P) |
Borehole |
11 |
1 |
||
|
2209/SCL/EDH039 |
Borehole |
9 |
1 |
||
|
2209/SCL/EDH042 |
Borehole |
7 |
1 |
||
|
2209/SCL/EDH043 |
Borehole |
7 |
1 |
||
|
2209/SCL/EDH045 |
Borehole |
7 |
1 |
||
|
2209/SCL/EDH046(P) |
Borehole |
10 |
1 |
||
|
Total No. of Samples
taken |
240 |
22 |
|
||
As
discussed in Section 12.3, CARs of SCL (MKK-HUH) and SCL (TAW-HUH) have been reviewed and results
indicated that no exceedance of RBRG levels for
industrial purpose was found in all the soil and groundwater samples collected
in respective areas.
A site survey was also conducted on 28 June 2011 for the current study to verify findings of desktop review and to visit the track area in the Hung Hom Freight Yard at the eastern portion of the Hung Hom Works Site which has not been surveyed in previous land contamination studies. No additional land contamination hotspot was observed and further site investigation was not considered necessary. No land contamination issues due to the Project would be anticipated.
A land contamination assessment has been conducted for the Project. A Contamination Assessment Plan (CAP) (as attached in Appendix 12.1) has also been prepared and submitted to EPD in August 2011 to review findings of previous site investigations and set out the requirements for a contamination evaluation of the Project. No adverse land contamination impacts would be anticipated within or in close proximity to the Project site boundary.