Expansion of Hong Kong International Airport into a Three-Runway System

Supplementary Contamination Assessment Plan

October 2017

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Contents

1       Introduction

1.1     Background

1.2     Objectives

1.3     Report Structure

2       Assessment Criteria and Methodology

2.1     Relevant Standards, Guidelines and Requirements

2.2     Assessment Methodology

3       Appraisal of Land Contamination Potential

3.1     Review of Relevant Information from Government Departments

3.1.1       Environmental Protection Department

3.1.2       Fire Services Department

3.2     Site Reconnaissance Survey

3.2.1       Fuel Tank Room to the West of CAD Antenna Farm

3.2.2       Fuel Tank Room within T2 Building

3.2.3       Seawater Pump House

3.2.4       Pumping Station

3.2.5       Fire Training Facility

3.3     Identification of Land Contamination Potential

4       Proposed Site Investigation Works

4.1     Site Investigation Works Proposed in EIA Stage

4.1.1       Fuel Tank Room to the West of CAD Antenna Farm

4.1.2       Fuel Tank Room within T2 Building

4.2     Additional Site Investigation Works

4.2.1       Fire Training Facility

4.3     Sampling Details

4.3.1       Sampling and Testing Plan

4.3.2       Soil Sampling Method and Depth of Sampling

4.3.3       Strata Logging

4.3.4       Free Product and Groundwater Level Measurement

4.3.5       Groundwater Sampling

4.3.6       Sample Size and Decontamination Procedures

4.3.7       Quality Assurance / Quality Control Procedures

4.3.8       Health and Safety

5       Proposed Laboratory Analysis

5.1     Fire Training Facility

5.2     Interpretation of Results

5.3     Reporting

6       Potential Remediation Measures

7       Conclusion

Appendices

A.      Documentation from EPD and FSD

B.      Site Walkover Checklists

C.      Proposed SI Locations in the EIA

D.      Schematic Drawing of Groundwater Monitoring Well

 

Figures

Figure 1.1 Land Contamination Assessment Areas

Figure 3.1 Photographic Record of Land Contamination Assessment Areas (Sheet 1 of 3)

Figure 3.2 Photographic Record of Land Contamination Assessment Areas (Sheet 2 of 3)

Figure 3.3 Photographic Record of Land Contamination Assessment Areas (Sheet 3 of 3)

Figure 4.1 Proposed Sampling Locations for Fire Training Facility

 

 

 

 

 

 

 


1        Introduction

1.1        Background

The Environmental Impact Assessment (EIA) Report (Register No.: AEIAR-185/2014) prepared for the “Expansion of Hong Kong International Airport into a Three-Runway System” (the project) has been approved by the Director of Environmental Protection, and an Environmental Permit (EP) (Permit No.: EP-489/2014) has been issued for the project under the Environmental Impact Assessment Ordinance.

As part of the EIA study, a Contamination Assessment Plan (CAP) (hereafter referred to as the Approved CAP) was prepared and presented as Appendix 11.1 of the approved EIA Report. In accordance to Section 8.1.1.1 of the Updated Environmental Monitoring and Audit (EM&A) Manual, which was submitted under Condition 3.1 of the EP, and Section 11.10.1.2 of the EIA Report, six areas (i.e. fuel tank room within Terminal 2 (T2) building, fuel tank room to the west of Civil Aviation Department (CAD) antenna farm, seawater pump house, switching station, pumping station and fire training facility), as presented in Figure 1.1, were inaccessible for site reconnaissance at the time of preparing the EIA Report.

According to Sections 11.5.4.14 and 11.5.4.37 of the EIA Report, it is anticipated that any potential land contamination concern related to possible leakage/ spillage of fuel in the fuel tank room within T2 building and fuel tank room to the west of CAD antenna farm will not cause any insurmountable impact. Furthermore, as mentioned in Sections 11.5.4.38, 11.5.4.47 and 11.5.4.50 of the EIA Report, the seawater pump house, switching station, pumping station and fire training facility are not identified as potential contaminative land use types as given in Table 2.3 of the Practice Guide for Investigation and Remediation of Contaminated Land, hence no potential land contamination along these areas are anticipated.

As part of the ongoing detailed design of the project, relocation of the switching station is no longer required for the modification of existing North Runway. Hence site appraisal process for land contamination potential at the switching station is considered not necessary. Further site reconnaissance has been carried out at the remaining five assessment areas (i.e. the fuel tank room within T2 building, fuel tank room to the west of CAD antenna farm, seawater pump house, pumping station and fire training facility) to confirm the findings under EIA stage. Subject to the further site reconnaissance findings, a Supplementary CAP shall be prepared in accordance with EP Condition 2.20 and submitted to the Environmental Protection Department (EPD) for endorsement. Mott MacDonald Hong Kong Limited (MMHK), as the project’s Environmental Team, was appointed by Airport Authority Hong Kong (AAHK) to establish a Supplementary CAP to fulfil the EP Condition 2.20.

1.2        Objectives

This Supplementary CAP is prepared to fulfil the EP Condition 2.20 and the objectives of this Supplementary CAP are to:

    Present the findings of further site reconnaissance;

    Propose additional site investigation (SI) if necessary, and

    Propose, where necessary, sampling and laboratory chemical analysis required to determine the nature and extent of any potential land contamination identified.

After the completion of SI works, if any, the results will be reported in the Contamination Assessment Report (CAR). Nevertheless, it is anticipated that any potential land contamination concern related to possible leakage/ spillage of fuel is not anticipated to cause any insurmountable impact.

1.3        Report Structure

Section 1          Introduction

Section 2          Assessment Criteria and Methodology

Section 3          Appraisal of Land Contamination Potential

Section 4          Proposed Site Investigation Works

Section 5          Proposed Laboratory Analysis

Section 6          Potential Remediation Measures

Section 7          Conclusion

 

2        Assessment Criteria and Methodology

2.1        Relevant Standards, Guidelines and Requirements

As described in Section 11.2 of the EIA Report, EPD promulgated two guidelines for utilising the Risk-based Remediation Goals (RBRGs) developed for Hong Kong, namely, “Guidance Note for Contaminated Land Assessment and Remediation” (Guidance Note) in August 2007 and “Guidance Manual for Use of Risk-based Remediation Goals for Contaminated Land Management” (Guidance Manual) in December 2007.  The land contamination assessment should be carried out in accordance with the Guidance Manual and Guidance Note as well as section 3 of Annex 19 of the Technical Memorandum on EIA Process issued under the EIA Ordinance (EIAO-TM). In addition, reference would also be made to the “Practice Guide for Investigation and Remediation of Contaminated Land” (Practice Guide).

2.2        Assessment Methodology

Further site reconnaissance was undertaken to identify the presence of any potentially contaminative land within the assessment areas. Relevant information was gathered with collection of latest records from the relevant Government departments and reviewed in preparing the Supplementary CAP, including:

    The Approved CAP;

    Records of active (current) and inactive (past) registered chemical waste producers at the assessment areas from the EPD;

    Records of current and past dangerous goods (DG) licences at the assessment areas from the Fire Service Department (FSD); and

    Records of accidents that involved spillage/ leakage of chemical waste or DG from EPD and FSD.

 

3        Appraisal of Land Contamination Potential

3.1        Review of Relevant Information from Government Departments

Information from the EPD and FSD have been collected and reviewed during the EIA stage. The EPD and FSD have been re-contacted to collect the latest information of the assessment areas to confirm the findings in the EIA Report. Latest information collected are listed below:

    Records of active (current) and inactive (past) registered chemical waste producer(s) and any reported accidents of chemical spillage/leakage at the assessment areas; and

    Records of any licensed DG store(s) and any reported accidents of spillage/ leakage of DG at the assessment areas.

Relevant documentation from EPD and FSD is provided in Appendix A and the information provided is summarised below.

3.1.1           Environmental Protection Department

A review of the chemical waste producer (CWP) records was conducted at the EPD’s Territory Control Office. No registered CWP was identified at the assessment areas.

Based on the information given by EPD, there is no record of chemical spillage/ leakage within the assessment areas as shown in Appendix A.

The above-mentioned findings are consistent with the information presented in Section 11.5.1.3 of the EIA Report.

3.1.2           Fire Services Department

According to the reply from FSD, there are three DG records at the assessment areas including a 900 L diesel tank at the fuel tank room to the west of CAD antenna farm, a 3,000 L above-ground diesel tank at the fuel tank room within T2 building and a 10,000 L above-ground kerosene tank at the fire training facility. The DG records are considered valid based on the findings of the site reconnaissance survey as presented in Section 3.2.

FSD reported that no incident of spillage/ leakage of DG was found within the assessment areas. The response from FSD is shown in Appendix A.

3.2        Site Reconnaissance Survey

As mentioned in Sections 11.5.4.14 and 11.5.4.37 of the EIA Report, the fuel tank room to the west of CAD antenna farm and fuel tank room within T2 building were inaccessible due to safety and operational issues. SI has been proposed at these areas based on relevant drawings during EIA stage. As mentioned in Sections 11.5.4.38, 11.5.4.47 and 11.5.4.50 of the EIA Report, seawater pump house, pumping station and fire training facility were inaccessible. Further site reconnaissance surveys have been conducted under this Supplementary CAP at these areas, with details listed in the following sub-sections. A site walkover checklist has been filled in upon completion of site reconnaissance at each assessment area.

3.2.1           Fuel Tank Room to the West of CAD Antenna Farm

Access to the fuel tank room to the west of CAD antenna farm was granted by CAD operator and site reconnaissance survey was carried out on 18 May 2017. During the survey, a 900 L above-ground tank containing diesel fuel was found. The diesel fuel is used for the emergency power supply system. The tank is located on a concrete-paved ground and equipped with drip tray. Bund wall is also provided in the access of the fuel tank room. No oil stain or crack was found on the ground. SI has been proposed in Section 11.6.2.4 of the EIA Report for the above-ground fuel tank to ascertain any potential contamination issues before commencement of any construction works at this area. The proposed SI locations in the EIA Report (i.e.  BH16 and BH17) are still considered valid in this Supplementary CAP. The drawing MCL/P132/EIA/11-015 documented in the EIA Report is presented in Appendix C for reference.

The completed site walkover checklist and the photographic records of the fuel tank room to the west of CAD antenna farm are provided in Appendix B and Figure 3.1 respectively.

3.2.2           Fuel Tank Room within T2 Building

A site reconnaissance survey was carried out at the fuel tank room within T2 building on 11 May 2017. During the survey, a 3,000 L above-ground tank containing diesel fuel was found. The diesel fuel is used for the emergency power supply system. The tank is located on a concrete-paved ground and equipped with drip tray. Bund wall is also provided in the access of the fuel tank room. No oil stain or crack was found on the ground. SI has been proposed in Section 11.6.2.2 of the EIA Report for the above-ground tank to ascertain any potential contamination issues before commencement of any construction works at this area. The proposed SI location in the EIA Report (i.e. BH9) is still considered valid in this Supplementary CAP. The drawing MCL/P132/EIA/11-014 documented in the EIA Report is presented in Appendix C for reference.

The completed site walkover checklist and the photographic records of the fuel tank room within T2 building are provided in Appendix B and Figure 3.2 respectively.

3.2.3           Seawater Pump House

As described in Section 11.5.4.38 of the EIA Report, the seawater pump house is used for delivering cooling water to different facilities for the operation of airport. A site reconnaissance survey was carried out at the seawater pump house on 22 September 2016.  During the survey, it was observed that only seawater pumps and control panels are located in the seawater pump house. The ground surfaces of seawater pump house are fully paved with intact concrete and no apparent stains were observed. Therefore, no signs of land contamination were observed at the seawater pump house during the survey.

As mentioned in Section 11.5.4.38 of the EIA Report, seawater pump house is not identified as one of the potential contaminative land use types in accordance with Table 2.3 of the Practice Guide. Therefore, taking into account the latest available information and the findings of site reconnaissance survey, no potential land contamination is anticipated at the seawater pump house and thus SI has not been recommended.

The completed site walkover checklist and the photographic records of the seawater pump house are provided in Appendix B and Figure 3.1 respectively.

3.2.4           Pumping Station

As mentioned in Section 11.5.4.47 of the EIA Report, the pumping station is used to convey sewage from T2 building. A site reconnaissance survey was carried out at the pumping station on 8 December 2016. During the survey, it was observed that control panels are located on the concrete-paved ground. Two sewage pumps are located underground to convey sewage from T2 building. No apparent stains were observed at the ground surface. As mentioned in Section 11.5.4.47 of the EIA Report, pumping station is not identified as one of the potential contaminative land use types in accordance with Table 2.3 of the Practice Guide. Therefore, taking into account the latest available information and the findings of site reconnaissance survey, no potential land contamination is anticipated at the pumping station and thus SI has not been recommended.

The completed site walkover checklist and the photographic records of the pumping station are provided in Appendix B and Figure 3.2 respectively.

3.2.5           Fire Training Facility

As mentioned in Section 11.5.4.50 of the EIA Report, the fire training facility is used for fire training exercises. Access was granted by FSD operator and a site reconnaissance survey was carried out at the fire training facility on 11 May 2017. A simulator is located at the centre of facility for fire training exercise. The whole training area is concrete paved. No oil stain or crack was found on the ground. An effluent pit is located under the simulator for collection of stormwater and water generated from fire training exercise. The collected stormwater will be stored in the three underground storage tanks and convey to the wastewater treatment plant for treatment.

As mentioned in Section 11.5.4.50 of the EIA Report, fire training facility is not identified as one of the potential contaminative land use types as given in Table 2.3 of the Practice Guide. During the survey, a 10,000 L above-ground tank containing kerosene was found. The tank is located on a concrete-paved ground and is surrounded by concrete bund wall on all four sides. No oil stain or crack was found on the ground. According to the latest information from detailed design consultant, a new fire training facility is planned to be constructed in the western support area to replace the existing training facility; however, demolition of the existing above-ground kerosene tank is yet to be confirmed and still subject to detailed design. SI is proposed for the kerosene tank to ascertain any potential contamination issues before commencement of any construction works at this area, and details will be discussed in Section 4. Nevertheless, it is anticipated that any potential land contamination concern related to possible leakage/spillage of fuel will not cause any insurmountable impact.

The completed site walkover checklist and the photographic records of the fire training facility are provided in Appendix B and Figure 3.3 respectively.

3.3        Identification of Land Contamination Potential

Based on the findings obtained from review of the Government responses as well as the site reconnaissance survey, only the fire training facility has been identified as a potentially contaminated site in this Supplementary CAP, in addition to those which have already been identified in the Approved CAP. Additional SI works are therefore proposed for this area as detailed in Section 4.

As described in Section 3.2.1 and 3.2.2, the proposed SI locations at the fuel tank room to the west of CAD antenna farm and fuel tank room within T2 building presented in the EIA Report (i.e. MCL/P132/EIA/11-014 and MCL/P132/EIA/11-015 in Appendix C) are still considered valid. 

A summary of further site investigation recommended in this Supplementary CAP is presented in Table 3.1.

Table 3.1: Summary of Further Site Investigation Recommended

Location

Potential Land Contamination Impact

Need for Further Site Investigation

Figure No.

Fuel Tank Room to the West of CAD Antenna Farm

A 900 L above-ground tank containing diesel fuel was found during the site reconnaissance survey. Potential leakage or spillage of fuel may cause land contamination concern.

SI locations have been proposed during EIA stage and are still considered valid. SI will be conducted prior to the commencement of construction works at site.

Figure 3.1 and EIA drawing MCL/P132/EIA/11-015 as presented in Appendix C

Fuel Tank Room within T2 Building

A 3,000 L above-ground tank containing diesel fuel was found during the site reconnaissance survey. Potential leakage or spillage of fuel may cause land contamination concern.

SI locations have been proposed during EIA stage and are still considered valid. SI will be conducted prior to the commencement of construction works at site.

Figure 3.2 and EIA drawing MCL/P132/EIA/11-014 as presented in Appendix C

Seawater Pump House

No contaminative land use types were identified.

No

Figure 3.1

Switching Station

During detailed design of the project, relocation of the switching station is no longer required. Therefore, site appraisal process for land contamination potential is considered not necessary.

Figure 3.1

Pumping Station

No contaminative land use types were identified.

No

Figure 3.2

Fire Training Facility

A 10,000 L above-ground tank containing kerosene was found during the site reconnaissance survey. Potential leakage or spillage of fuel may cause land contamination concern.

Yes, SI will be conducted prior to the commencement of construction works at site.

Figure 3.3


4        Proposed Site Investigation Works

4.1        Site Investigation Works Proposed in EIA Stage

4.1.1           Fuel Tank Room to the West of CAD Antenna Farm

As mentioned in Section 3.2.1, a 900 L above-ground tank containing diesel fuel was found during the site reconnaissance survey. A total of two boreholes (i.e. BH16 and BH17) were proposed in the EIA drawing MCL/P132/EIA/11-015 as presented in Appendix C for the above-ground fuel tank. The proposed SI locations are still considered valid in this Supplementary CAP. Sampling and testing works will be conducted prior to commencement of any construction works at this area.

4.1.2           Fuel Tank Room within T2 Building

As mentioned in Section 3.2.2, a 3,000 L above-ground tank containing diesel fuel was found during the site reconnaissance survey. One borehole (i.e. BH9) was proposed in the EIA drawing MCL/P132/EIA/11-014 as presented in Appendix C for the 3,000 L above-ground fuel tank. The proposed SI location is still considered valid in this Supplementary CAP. Sampling and testing works will be conducted prior to commencement of any construction works at this area.  

4.2        Additional Site Investigation Works

4.2.1           Fire Training Facility

As mentioned in Section 3.2.5, the fire training facility is not identified as one of the potential contaminative land use types as given in Table 2.3 of the Practice Guide. A 10,000 L above-ground tank containing kerosene fuel was found during the site reconnaissance survey, hence SI is proposed for this above-ground kerosene tank.

One new borehole (BH18) is proposed at the 10,000 L above-ground fuel tank inside the fire training facility. The tentative sampling location is shown in Figure 4.1. Sampling and testing works will be conducted prior to commencement of any construction works at this area.  

4.3        Sampling Details

4.3.1           Sampling and Testing Plan

The sampling and testing plan, including sampling locations and depths, is recommended in accordance with the EPD’s Practice Guide for Investigation and Remediation of Contaminated Land as shown in Table 4.1. The exact locations and depths for soil and groundwater sampling shall be determined by the on-site land contamination specialist to suit the actual site condition during site investigation.

Table 4.1: Sampling and Testing Plan

Proposed Sampling Locations

Sample Matrix2

Parameters to be Tested3

Rationale of Sampling

 

Heavy Metals

PCRs4

VOCs4

SVOCs4

 

 

Fuel Tank Room within T2 Building*

 

BH91

Soil

0.5 m, 1.5 m, 3.0 m bgs

Full list

Assess potential land contamination impact from the above-ground fuel tank

 

GW

If present^

Mercury only

 

Fuel Tank Room to the West of CAD Antenna Farm*

 

BH161

Soil

0.5 m, 1.5 m, 3.0 m bgs

Full list

Assess potential land contamination impact from the fuel tank

 

GW

If present^

Mercury only

 

BH171

Soil

0.5 m, 1.5 m, 3.0 m bgs

Full list

Assess potential land contamination impact from the fuel tank

 

GW

If present^

Mercury only

 

Fire Training Facility

 

BH181

Soil

0.5 m, 1.5 m, 3.0 m bgs

Full list

Assess potential land contamination impact from the above-ground fuel tank

 

GW

If present^

Mercury only

 

 

Remarks:

1 Exact sampling locations will be identified on site after the removal of the fuel tank.

2 bgs = Below Ground Surface; GW = groundwater.

3 ü = testing proposed.

4 PCRs = Petroleum Carbon Ranges; VOCs = Volatile Organic Chemicals; SVOCs = Semi-volatile Organic Chemicals;

^ Samples will only be collected if groundwater is encountered during SI works.

* The sampling and testing plan for Fuel Tank Room within T2 Building and Fuel Tank Room to the West of CAD Antenna Farm are extracted from Table 4.2 of the Approved CAP.

4.3.2           Soil Sampling Method and Depth of Sampling

All soil boring / excavation and sampling should be supervised by a land contamination specialist.

Borehole should be undertaken by means of dry rotary drilling method, i.e. without the use of flushing medium, to prevent cross-contamination during sampling.  For safety reasons, an inspection pit should be excavated down to 1.5 m below ground surface (bgs) to inspect for underground utilities at the proposed borehole location. Disturbed soil samples should be collected at depth of 0.5 m bgs.  Soil boring using drill rigs should then be performed from depth of 1.5 m bgs to the maximum boring depth.  Undisturbed U100/U76 soil samples should be collected at 1.5 m and 3.0 m bgs as well as above groundwater level. Groundwater samples should be collected at the level of groundwater (if encountered).

Where borehole drilling is not possible due to site constraints (e.g. insufficient head room or accessibility of drilling rigs), sampling using trial pit methods will be adopted. For trial pit methods, disturbed soil samples, using stainless steel hand tools, will be taken at 0.5 m, 1.5 m and 3.0 m bgs in order to delineate the vertical profile of contamination.

Appropriate safety precautionary measures such as shoring support, stepping/sloping of sides will be implemented for the excavation of trial pit exceeding 1.2 m, with reference to the “Practice Guide for Investigation and Remediation of Contaminated Land” issued by EPD and “Guide to Trench Excavations (Shoring Support and Drainage Measures)” issued by Utilities Technical Liaison Committee of Highway Department and Geotechnical Engineering Office of Civil Engineering Department.

At each sampling location/depth, sufficient quantity of soil sample (as specified by the laboratory) should be taken. All soil samples should be uniquely labelled.  Backup samples should be retained and stored at 0-4 ºC in laboratory.

4.3.3           Strata Logging

Strata logging for boreholes should be undertaken during the course of drilling/digging and sampling by a qualified geologist.  The logs should include the general stratigraphic description, depth of soil sampling, sample notation and level of groundwater (if encountered).  The presence of rocks/boulders/cobbles and foreign materials such as metals, wood and plastics should also be recorded.

4.3.4           Free Product and Groundwater Level Measurement

The thickness of any free product and ground water level (if present) at sampling locations should be measured with an interface probe.  The free product (if encountered in sufficient amounts) should be collected for laboratory analysis to determine the composition.

4.3.5           Groundwater Sampling

It is proposed to collect groundwater samples if groundwater is encountered at the sampling locations.

For each proposed borehole sampling location, a groundwater sampling well should be installed into the boreholes if groundwater is encountered or agreed by the land contamination specialist. A typical configuration of a groundwater monitoring well is shown in Appendix D. After installation of the monitoring wells, the depth to water table at all monitoring wells should be measured at the same time with an interface probe in order to delineate the groundwater table contours at the subject site.  Well developments (approximately five well volumes) should be carried out to remove silt and drilling fluid residue from the wells.  The wells should then be allowed to stand for a day to permit groundwater conditions to equilibrate.  Groundwater level and thickness of free product layer, if present, should be measured at each well before groundwater samples are taken.

Prior to groundwater sampling, the monitoring wells should be purged (at least three well volumes) to remove fine-grained materials and to collect freshly refilled representative groundwater samples.

After purging, one groundwater sample should then be collected at each well using Teflon bailer and decanted into appropriate sample vials or bottles in a manner that minimises agitation and volatilization of volatile organic chemicals (VOCs) from the samples.  All samples should be uniquely labelled. 

If required, one groundwater sample at each trial pit using Teflon bailer should be taken if groundwater is encountered. The groundwater should only be taken after all required soil samples at the sampling location have been collected. The trial pit should be pumped to near dry and allowed to stand for 24 hours before sampling.

If groundwater sample is collected in trial pit, the trial pit should be enclosed on four sides by impervious sheeting at the end of each day to avoid potential contamination such as dust from the surrounding environment during groundwater sampling.

Immediately after collection, groundwater samples should be transferred to new, clean, laboratory-supplied glass jars for sample storage/transport.  The sampling glass jars should be of “darkened” type.  Groundwater samples should be placed in the glass jars with zero headspace and promptly sealed with a septum-lined cap.  Immediately following collection, samples should be placed in ice chests, cooled and maintained at a temperature of about 4 ºC until delivered to the analytical laboratory.

4.3.6           Sample Size and Decontamination Procedures

All equipment in contact with the ground should be thoroughly decontaminated between each excavation, drilling and sampling event to minimise the potential for cross contamination.  The equipment (including drilling pit, digging tools and soil/groundwater samplers) should be decontaminated by steam cleaning or high-pressure hot water jet, then washed by phosphate-free detergent and finally rinsed by distilled / deionised water.

Prior to sampling, the laboratory responsible for analysis should be consulted on the particular sample size and preservation procedures that are necessary for each chemical analysis.

The sample containers should be laboratory cleaned, sealable, water-tight, made of glass or other suitable materials with aluminium or Teflon-lined lids, so that the container surface will not react with the sample or adsorb contaminants. No headspace should be allowed in the containers which contain samples to be analysed for VOCs, Petroleum Hydrocarbon Ranges or other volatile chemicals.

The containers should be marked with the sampling location codes and the depths at which the samples were taken.  If the contents are hazardous, this should be clearly marked on the container and precautions taken during transport. Samples should be stored at between 0-4 ºC but never frozen.  Samples should be delivered to laboratory within 24 hours of the samples being collected and analysed within the respective retention period but should not be more than 10 days.

4.3.7           Quality Assurance / Quality Control Procedures

Quality Assurance / Quality Control (QA/QC) samples should be collected with the following frequency during the SI. Chain of Custody protocol should be adopted.

    One equipment blank per 20 samples for full suite analysis;

    One field blank per 20 samples for full suite analysis;

    One duplicate sample per 20 samples for full suite analysis; and

    One trip blank per trip for the analysis of volatile parameters.

4.3.8           Health and Safety

The specific safety measures to be taken depend on the nature and content of contamination, the site conditions and the regulations related to site safety requirements.  Workers Compensation Insurance and third party insurance must be provided for the SI.

Extreme care should be exercised when toxic gases or other hazardous materials are encountered.  Any abnormal conditions found shall be reported immediately to the safety officer and the land contamination specialist.

The SI contractor shall establish and maintain a Health and Safety Plan before commencement of the SI that will include the following:

    Instruction of works on work procedures, safe practices, emergency duties, and applicable regulations;

    Regularly scheduled meetings of the workers in which the possible hazards, problems of the job, and related safe practices are emphasised and discussed;

    Good housekeeping practices; and

    Availability of and instruction in the location, use and maintenance of personal protective equipment.

The SI Contractor shall maintain equipment and supplies reasonably required in an emergency, including lifesaving, evacuation, rescue and medical equipment in good working order and condition at all times.  The SI Contractor shall use all reasonable means to control and prevent fires and explosions, injury to personnel and damage to equipment of property.  Without limiting the foregoing, the SI Contractor shall:

    Maintain proper safety devices and barriers to minimise hazards during performance of the work;

    Prohibit smoking and open flames and the carrying of matches and lighters;

    Develop and maintain a written emergency plan applicable to the work site;

    Maintain equipment in good operating condition and have emergency and first aid equipment ready for immediate use, where applicable;

    Conduct equipment tests to ensure that equipment is properly placed and in good operating condition, and that workers are able to respond to emergency situations;

    Require all workers employed or retained by the Contractor, or a subcontractor, to at all time wear clothing suitable for existing work, weather and environmental conditions;

    Require the site personnel to wear respirator and gloves for vapour exposure protection, if necessary; and

    Ensure all site staff members wear safety helmet and protective boots.

 

5        Proposed Laboratory Analysis

5.1        Fire Training Facility

Laboratory analysis is proposed for the soil and groundwater (if any) samples collected at the fire training facility in order to screen the presence of potential contaminants that are of concerns as shown in Table 4.1.

Table 5.1 summarises the parameters, the minimum requirement of the reporting limits and reference methods for the laboratory analyses of soil and groundwater samples.

Table 5.1: Parameters, Detection Limits and Reference Methods for Laboratory Analysis

Parameter

Soil

Groundwater

 

Detection Limit (mg/kg) or other stated

Reference Method

Detection Limit (µg/L) or other stated

Reference Method

VOCs

Acetone

50

USEPA 8260 or similar method*

500

USEPA 8260 or similar method*

Benzene

0.2

5

Bromodichloromethane

0.1

5

2-Butanone

5

50

Chloroform

0.04

5

Ethylbenzene

0.5

5

Methyl tert-Butyl Ether

0.5

5

Methylene Chloride

0.5

50

Styrene

0.5

5

Tetrachloroethene

0.04

5

Toluene

0.5

5

Trichloroethene

0.1

5

Xylenes (Total)

2

20

SVOCs

Acenaphthene

0.5

USEPA 8270D or similar method*

2

USEPA 8270D or similar method*

Acenaphthylene

0.5

2

Anthracene

0.5

2

Benzo(a)anthracene

0.5

N/A

Benzo(a)pyrene

0.5

N/A

Benzo(b)fluoranthene

0.5

1

Benzo(g,h,i)perylene

0.5

N/A

Benzo(k)fluoranthene

0.5

N/A

Bis-(2-Ethylhexyl)phthalate

5

N/A

Chrysene

0.5

1

Dibenzo(a,h)anthracene

0.5

N/A

Fluoranthene

0.5

2

Fluorene

0.5

2

Hexachlorobenzene

0.2

4

Indeno(1,2,3-cd)pyrene

0.5

N/A

Naphthalene

0.5

2

Phenanthrene

0.5

2

Phenol

0.5

N/A

Pyrene

0.5

2

Metals

Antimony

1

USEPA 6020 or similar method*

N/A

USEPA 6020 or similar method*

Arsenic

1

N/A

Barium

1

N/A

Cadmium

0.2

N/A

Chromium III

1

N/A

Chromium VI

1

N/A

Cobalt

1

N/A

Copper

1

N/A

Lead

1

N/A

Manganese

1

N/A

Mercury

0.05

0.5

Molybdenum

1

N/A

Nickel

1

N/A

Tin

1

N/A

Zinc

1

N/A

Petroleum Carbon Ranges

 

C6 - C8

5

USEPA 8260B /  8015 or similar method*

20

USEPA 8260B /  8015 or similar method*

C9 - C16

200

500

C17 - C35

500

500

PCBs

 

PCBs

0.1

USEPA 8070 or similar method*

1

USEPA 8070 or similar method*

Remark:

*  Alternative testing methods with accreditation by HOKLAS or its Mutual Recognition Arrangement partner are also acceptable.

N/A - Not Available.

5.2        Interpretation of Results

The soil and groundwater samples collected from the proposed SI works will be compared with RBRGs as stipulated in Table 2.1 and Table 2.2 of the Guidance Manual.

The RBRGs are developed based on a risk assessment approach to suit the local environmental conditions and community needs in Hong Kong. Decisions on contaminated soil and groundwater (if any) remediation are based on the nature and extent of the potential risks that are posed to human receptors as a result of exposure to chemicals in the soil and/or groundwater. RBRGs are developed for four different land use scenarios reflecting the typical physical settings in Hong Kong under which people could be exposed to contaminated soil and groundwater. Each land use scenario is described below:

    Urban Residential – Sites located in an urban area where main activities involve habitation by individuals. The typical physical setting is a high rise residential building situated in a housing estate that has amenity facilities such as landscaped yards and children’s playgrounds. The receptors are residents who stay indoors most of the time except for a short period each day, during which they are outdoors and have the chance of being in direct contact with soil at landscaping or play areas within the estate.

    Rural ResidentialSites located in a rural area where the main activities involve habitation by individuals. These sites typically have village-type houses or low rise residential blocks surrounded by open space. The receptors are rural residents who stay at home and spend some time each day outdoors on activities such as gardening or light sports. The degree of contact with the soil under the rural setting is more than that under the urban setting both in terms of intensity and frequency of contact.

    Industrial – Any site where activities involve manufacturing, chemical or petrochemical processing, storage of raw materials, transport operations, energy production or transmission, etc. Receptors include those at sites where part of the operation is carried out directly on land and the workers are more likely to be exposed to soil than those working in multi-storey factory buildings.

    Public Parks – Receptors include individuals and families who frequent parks and play areas where there is contact with soil present in lawns, walkways, gardens and play areas. Parks are considered to be predominantly hard covered with limited areas of predominantly landscaped soil. Furthermore, public parks are not considered to have buildings present on them.

In addition to the RBRGs, screening criteria (soil saturation limits, Csat, developed for Non-aqueous Phase Liquid (NAPL) in soil and water solubility limits for NAPL in groundwater) for the more mobile organic chemicals must be considered to determine whether a site requires further action.

Since the future land uses of the fire training facility will be used for operations of the airport, the RBRGs corresponding to the land use categories of Industrial should be adopted according to the Guidance Note.

The relevant parameters and soil and groundwater RBRGs levels for the SI works are presented in Table 5.2.

Table 5.2: Relevant RBRGs for Soil and Groundwater

Parameter

Soil

Groundwater

 

RBRGs for Industrial (mg/kg)

Soil Saturation Limit (Csat) (mg/kg)

RBRGs for Industrial (mg/L)

Groundwater Solubility Limit (mg/L)

VOCs

 

 

 

 

Acetone

10,000*

***

10,000*

N/A

Benzene

9.21

336

54

1750

Bromodichloromethane

2.85

1030

26.2

6740

2-Butanone

10,000*

***

10,000*

N/A

Chloroform

1.54

1100

11.3

7920

Ethylbenzene

8,240

138

10,000*

169

Methyl tert-Butyl Ether

70.1

2380

1,810

N/A

Methylene Chloride

13.9

921

224

N/A

Styrene

10,000*

497

10,000*

310

Tetrachloroethene

0.777

97.1

2.95

200

Toluene

10,000*

235

10,000*

526

Trichloroethene

5.68

488

14.2

1100

Xylenes (Total)

1,230

150

1,570

175

SVOCs

 

 

 

 

Acenaphthene

10,000*

60.2

10,000*

4.24

Acenaphthylene

10,000*

19.8

10,000*

3.93

Anthracene

10,000*

2.56

10,000*

0.0434

Benzo(a)anthracene

91.8

N/A

N/A

N/A

Benzo(a)pyrene

9.18

N/A

N/A

N/A

Benzo(b)fluoranthene

17.8

N/A

7.53

0.0015

Benzo(g,h,i)perylene

10,000*

N/A

N/A

N/A

Benzo(k)fluoranthene

918

N/A

N/A

N/A

Bis-(2-Ethylhexyl)phthalate

91.8

N/A

N/A

N/A

Chrysene

1140

N/A

812

0.00160

Dibenzo(a,h)anthracene

9.18

N/A

N/A

N/A

Fluoranthene

10,000*

N/A

10,000*

0.206

Fluorene

10,000*

54.7

10,000*

1.98

Hexachlorobenzene

0.582

N/A

0.695

6.2

Indeno(1,2,3-cd)pyrene

91.8

N/A

N/A

N/A

Naphthalene

453

125

862

31

Phenanthrene

10,000*

28.0

10,000*

1

Phenol

10,000*

7260

N/A

N/A

Pyrene

10,000*

N/A

10,000*

0.135

Metals

 

 

 

 

Antimony

261

N/A

N/A

N/A

Arsenic

196

N/A

N/A

N/A

Barium

10,000*

N/A

N/A

N/A

Cadmium

653

N/A

N/A

N/A

Chromium III

10,000*

N/A

N/A

N/A

Chromium VI

1960

N/A

N/A

N/A

Cobalt

10,000*

N/A

N/A

N/A

Copper

10,000*

N/A

N/A

N/A

Lead

2290

N/A

N/A

N/A

Manganese

10,000*

N/A

N/A

N/A

Mercury

38.4

N/A

6.79

N/A

Molybdenum

3260

N/A

N/A

N/A

Nickel

10,000*

N/A

N/A

N/A

Tin

10,000*

N/A

N/A

N/A

Zinc

10,000*

N/A

N/A

N/A

Petroleum Carbon Ranges

 

 

 

 

C6 - C8

10,000*

1,000

1,150

5.23

C9 - C16

10,000*

3,000

9,980

2.8

C17 - C35

10,000*

5,000

178

2.8

PCBs

 

 

 

 

PCBs

0.748

N/A

5.11

0.031

Remark:

*Indicates a ‘ceiling limit’ concentration.                                               

N/A - Not Available.

5.3        Reporting

According to Section 11.6.1 of the EIA Report, SI works at SkyCity Golf Course (hereafter referred to as the golf course) will be carried out by Airport Management Services (AMSL). The golf course was closed on 31 July 2015 after expiry of operation. SI works proposed in the EIA Report was conducted in August 2015. The SI results were presented in the Contamination Assessment Report (for Golf Course Area) which was approved by EPD on 6 April 2016.

The rest of the SI works proposed in the EIA Report have not been commenced. After the SI works as mentioned in the EIA Report and this Supplementary CAP have been completed, a corresponding Contamination Assessment Report (CAR) which documents the detailed methodology of SI, assessment criteria, on-site observations and the analytical results from the SI works will be submitted to EPD for endorsement. Should remediation be required, Remediation Action Plan (RAP) and Remediation Report (RR) will be prepared for EPD’s approval prior to commencement of the proposed remediation and any construction works respectively.

 

6        Potential Remediation Measures

The possible contaminants that may be found at the assessment areas in this Supplementary CAP include heavy metals, organic compounds and PCRs. Possible remediation methods will be applied depending on the quantity and quality of contaminated soil. With reference to the Practice Guide, a list of available and commonly adopted remediation methods is presented in Table 6.1 for the potential contaminated soil.

Table 6.1: List of Potential Remediation Methods

Remediation Options

Possible Contaminants

Descriptions

Contaminated Soil

Stabilisation/ Solidification

Heavy metals

Ex-situ immobilisation technique treating contaminated soil by mixing soil with binding agents. The most common binding agent is cement

Biopiling

PCRs and Organic contaminants

Ex-situ bioremediation method that facilitate bacterial growth in contaminated soil and degradation of contaminants into harmless products

Soil Vapour Extraction (SVE)

PCRs and Organic contaminants

In-situ bioremediation method by removal of contaminants by suction / volatilisation, in the form of vapours. The vapours can be extracted by applying vacuum

Thermal Desorption

PCRs and Organic contaminants

A method to remove / separate contaminants from the soil matrix. Apply heat to the contaminated soil in order to increase the volatility of contaminants

Contaminated Groundwater

Air Sparging

PCRs and Organic contaminants

In-situ remediation technique to inject pressurised air into contaminated water enabling a phase transfer of hydrocarbons from a dissolved state to a vapour phase. Vacuum extraction is then applied to remove the contaminants

Recovery Trenches / Wells

PCRs

Pump the groundwater out for recovering of free floating products from a plume

If any contamination is identified and warrant remediation based on the SI result, a RAP presenting the proposed remediation methods will be prepared and submitted to EPD for approval prior to commencement of the remediation works. As the remediation methods are well established and sufficient to deal with the nature of possible contaminants, it is anticipated that any contamination issues at the potentially contaminated areas will not cause any insurmountable impact.

 

 

7        Conclusion

This Supplementary CAP has been prepared in accordance with the EP Condition 2.20 to assess whether there are any potential land contamination issues at the assessment areas which have become accessible for site reconnaissance after the EIA stage.

There were no records of chemical waste spillage or leakage at the assessment areas, according to the information obtained from EPD. As a result, no land contamination due to spillage or leakage of chemical waste within the assessment areas would be anticipated. According to the information obtained from FSD, there were no recorded DG spillage/ leakage incidents at the assessment areas.

The proposed SI locations in the EIA Report at the fuel tank room to the west of CAD antenna farm and fuel tank room within T2 building are still considered valid. A borehole has been proposed in this Supplementary CAP to take into account the 10,000 L above-ground kerosene tank identified at the fire training facility during the site reconnaissance survey.

All sampling and testing works will be conducted prior to commencement of any construction works at these areas. After completion of the SI, the CAR will be prepared and submitted to EPD for approval prior to commencement of the proposed construction works at the assessment areas. Should remediation be required, RAP and RR will be prepared for EPD’s approval prior to commencement of the proposed remediation and any construction works respectively.