8                                            Land Contamination

8.1                                      Introduction

This section presents the potential hazard and land contamination issues and impacts associated with the operation of the Project, including karting activities, re-fuelling activities and the repair and maintenance activities to be carried out on site.  This section identifies potential sources of hazard and land contamination and where appropriate, proposes mitigation measures.

8.2                                      Legislative Requirements and Evaluation Criteria

Assessments of land contamination are guided by the EPD's guidance document the Technical Memorandum on Environmental Impact Assessment Process (EIAOTM).

The following legislation, documents and guidelines may also cover or have some bearing upon contamination and the handling, treatment and disposal of contaminated waste in Hong Kong:

·     Waste Disposal Ordinance (Cap 354);

·     Waste Disposal (Chemical Waste) (General) Regulation (Cap 354); and

·     Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes, Environmental Protection Department (1992).

8.3                                      Potential Sources of Impacts

8.3.1                                Construction Phase

Site levelling, compacting, track paving works, planting and fence installation are the major construction works and these would take approximately two months.  Potential sources of land contamination impacts associated with the construction of the karting tracks comprise:

·       Use of fuel and lubricants for machinery; and

·       Use of paints and improper handling of asphalt.

8.3.2                                Operational Phase

Based on the desktop review, site survey and experience from the HKKC, the potential sources of soil and groundwater contamination with specific relevance to the Project were identified as summarised as follows:

·       Use of fuel (petroleum) during karting activities and re-fuelling activities; and

·       Use of lubricant and solvents during repair and maintenance activities.

In addition, the main operational hazard associated with the karting track is the use of petroleum for the karting activities.  Also, it should be noted that all petrol kart drivers must have a licence issued by the HKKC.  The licence is issued under the condition that adequate training on kart driving and safety is obtained.  All drivers will have to follow standard safety regulations of kart racing. 

Not withstanding the above, should there be an accident with fire, all the activities inside the track area will be stopped compulsorily and staff members will perform fire fighting using the extinguisher and/or the fire-fighting sand.  Extinguisher and fire-fighting sand will be provided along the karting track at every 100m interval.  Extinguishers will also be provided within the service area and the office.

In addition, the karts will be re-fuelled once or twice a day within the service area.  As petrol is a highly flammable, explosive and volatile colourless or pale brown liquid, and presents a severe fire and explosion hazard when exposed to heat, flame or oxidisers, only limited quantities of petrol, a standard 18 litre safety petrol tank, will be stored on site during the daytime.  A licence dangerous goods (DG) vehicle would transport the petrol tank to site for re-fuelling and the karts will be re-fuelled using hand pump.  Any unused petrol will be collected by the DG vehicle after the operating time of the karting track.  

8.4                                      Assessment of Land Contamination Impacts

8.4.1                                Construction Phase

Potential sources of land contamination include:

·       Use of fuel, oil and lubricants for construction machinery and vehicles;

·       Release of grouting and cement materials with rain wash; and

·       Wash water from dust suppression sprays and vehicle wheel washing troughs.

Land contamination may result if the construction site runoff and fuel / oil leakages are allowed to drain into the storm sewer or natural drainage.  Nevertheless, with the proper implementation of the good site practices and housekeeping, as discussed in Section 6.6.1, unacceptable land contamination impacts are not expected.

General Construction Site Activities

On-site construction site activates may cause land contamination due to spillages of liquid stored on-site, such as oil, diesel and solvents etc.  The spillage of liquid may result in soil and groundwater contamination.

However, the effects on land contamination from the construction activities are likely to be limited, provided that the site are well maintained and good construction practices are implemented to ensure that oil, fuel and solvents are managed, stored and handled properly.

8.4.2                                Operational Phase

Potential leakage of fuel or lubricants during servicing

The main identified source of potential impact on land contamination during the operation phase will be leakage of fuel or lubricants during servicing, maintenance or refuelling activities.  There would be a vehicle and plant servicing area and repair / maintenance area at where maintenance of karts and oil filling activities would take place (see Figure 8.1).  Both the service and repair / maintenance areas will be concrete-paved.  In addition, karting activities will be undertaken on asphalt-paved tracks.  Any leakage of minimal amounts of oil, grease and grit may cause land contamination if uncontrolled. 

Potential operational hazard

As discussed in Section 8.3.2, the main identified source of potential hazard during the operation phase includes re-fuelling of the kart vehicles.

Petrol is a highly flammable, explosive and volatile colourless or pale brown liquid, and presents a severe fire hazard when exposed to heat, flame or oxidisers.  If immediately ignited a flammable liquid will form a burning pool whilst delayed ignition of the vapour may result in a flash fire.  However, in view of the limited quantities, the potential hazard is not expected to be a concern.  However, mitigation measures are recommended to further minimise the risk of any fire hazard.

8.5                                      Mitigation Measures

8.5.1                                Construction Phase

The following mitigation measures should be implemented during the construction of the karting track:

Construction Runoff and Drainage

Construction site runoff and drainage should be prevented or minimized in accordance with the guidelines stipulated in the EPD Practice Note for Professional Persons, Construction Site Drainage (ProPECC PN 1/94), so as to prevent any potential spillage of fuel or oils from entering the soil or storm water drains.  The practices include the following items:

·       Maintenance of heavy-duty machinery shall be minimised and should be carried out off-site.

·       Exposed soil surface shall be protected by paving as soon as possible to minimise exposure of soil to potential contaminating sources.

·       Provision of perimeter channels to intercept storm-runoff from outside the site.  These shall be constructed in advance of site formation works and earthworks.

·       The section of the road between the wheel washing facilities and the public road shall be paved with backfall to prevent wash water or other site runoff from entering public road drains.

General Construction Activities

All fuel tanks and storage areas shall be provided with locks and be sited on sealed areas, within bunds of a capacity equal to 110% of the storage capacity of the largest tank.  Open storm water drains and culverts near the works area shall be covered to block the entrance of large debris and refuse. 

8.5.2                                Operational Phase

Although no unacceptable land contamination impact is anticipated during the operational phase, the following measures are recommended:

Paving of servicing area

The servicing area, vehicle washing bays, lubrication bays and repair / maintenance area would be properly paved by concrete.  In addition, the servicing area should be located within roofed areas.  The drainage serving the servicing area and oil filling point would be connected to storm drains via a petrol interceptor with peak storm bypass.  Therefore, it is considered unlikely to produce any quantifiable adverse land contamination impacts.

Minimal and controlled re-fuelling activities

From the desktop review and site survey results, the fuel tank capacity of the kart is relatively small, i.e., about 3 litres, and re-fuelling is required once or twice a day.  The re-fuelling time would be about 15 seconds.  The maximum number of karts allowed on the track for training or rental run is 40 and 34 for match.  Given the small tank capacity and infrequent re-fuelling activities, the quantities of petroleum hydrocarbon products to be used on site would be minimal.

All the re-fuelling activities and repair and maintenance activities will be carried out under concrete-paved areas. 

Other mitigation measures

·       All karting activities should only be undertaken on asphaltic concrete paved tracks. 

·       Maintenance of karts should be performed regularly to avoid leakage of fuel on tracks;

·       Proper handling of petrol storage tank to avoid leakage of petrol, including the use of a secondary containment of a capacity equal to 110% of the storage capacity of the largest tank and a roof cover to separate rainfall.

·       Service area and repair / maintenance area should be concrete-paved.

·       Drainage serving the open oil filling point should be connected to storm drains via a petrol interceptor with peak storm bypass.

·       Vehicle and plant servicing areas, vehicle wash bays and lubrication bays should be located within roofed areas.  The drainage in these covered areas should be connected to foul sewers via a petrol interceptor. 

·       Oil leakage or spillage should be contained and cleaned up immediately.  Waste oil should be collected and stored for recycling or disposal in accordance with the Waste Disposal Ordinance.

To further minimise the operational hazard associated with the karting track, the following mitigation measures are recommended.

·       Smoking is prohibited within the site area;

·       Extinguishers and fire-fighting sand are located along the track at 100m interval;

·       Extinguishers are provided in the office and the service area;

·       Re-fuelling should only be undertaken within the service area;

·       Only one tank of petrol with a maximum 18 litre is to be stored in a safety petrol tank within the servicing area;

·       No petrol should be stored on site overnight; and

·       Maintenance of karts should be performed regularly to avoid leakage of fuel on tracks.

Should there be an accident with fire, all the activities within the track would be stopped compulsorily and staff members will perform fire fighting using the extinguisher and/or the fire-fighting sand.

8.6                                      Environmental Monitoring and Audit

8.6.1                                Construction Phase

No monitoring on land contamination is required as no unacceptable impact on land contamination is expected.

8.6.2                                Operational Phase

No operational monitoring on land contamination is required as no adverse impact on land contamination is anticipated.

8.7                                      Conclusions

Given the small scale of the construction works, short duration of construction period and minimal use of heavy-duty construction machinery, fuel and oils, land contamination impacts are negligible during construction phase of the Project provided that good site practices and housekeeping are implemented as suggested in Section 8.5.1.  Hence, it is considered that no land contamination monitoring would be necessary to carry out during construction phase.    

For the operation of the Project, the main concern is the potential land contaminations caused by the karting activities, servicing, repairing and oil filling activities.  Nevertheless, all the above activities will be carried out on paved areas.  Any leakage can be well controlled by secondary containments or a proper drainage system with peripheral channel and petrol interceptor.  With consideration of the infrequent refuelling activities and the minimal amount of fuel handled each time, as well as proper handling of petrol tank, precaution on refuelling activities and regular maintenance of karts, no adverse impacts on land contamination are anticipated.  Therefore, it is suggested that no operational land contamination monitoring would be required.