5.0 WATER QUALITY IMPACT ASSESSMENT

5.1 Introduction

This section presents an assessment of the potential water quality impacts associated with the construction and operation phases of the Project. Appropriate mitigation measures are proposed to minimize any potential water quality impacts identified.

The water quality impact assessment and evaluation have been conducted in accordance with the criteria and guidelines as presented in Annexes 6 and 14 of the EIAO-TM respectively.

5.2 Environmental Legislation, Standards and Guidelines

The following legislation, Standards and Practice Notes are considered in the Project:

• Water Pollution Control Ordinance (Cap. 358): Water Quality Objectives (WQOs) for Deep Bay Water Control Zone (WCZ);

• Water Pollution Control Ordinance (Cap. 358): WQOs for Tolo Harbour and Channel WCZ;

• Water Pollution Control Ordinance (Cap. 358): Technical Memorandum on Standards for Effluents Discharged into Drainage and Sewerage Systems, Inland and Coastal Waters;

• EIAO (Cap. 499): Annexes 6 and 14 of TM-EIAO; and

• EPD’s Practice Notes for Professional Persons ProPECC PN 1/94 “Construction Site Drainage”

5.3 Description of the Environment

Water courses in the vicinity of the Project comprise the channelized Kam Tin River and a number of natural streams with unpolluted and polluted sections. The direction of flow is towards the Kam Tin River and ultimately Inner Deep Bay to the northwest for those water courses near Shek Kong Barracks and Wang Toi Shan Shan Tsuen, and the towards Lam Tsuen River and ultimately Tolo Harbour to the east for those water courses near Kadoorie Experimental Farm. Table 5.1 summarizes the WQOs for inland waters of Deep Bay WCZ and Tolo Harbour and Channel WCZ.

Table 5.1 Water Quality Objectives for Inland Waters of Deep Bay WCZ and Tolo Harbour and Channel WCZ

Parameters	Water Quality Objectives
pH	6.5 – 8.5
Suspended solids (SS)	Annual median 20mg/L
Dissolved oxygen (DO)	4 mg/L
Chemical oxygen demand (COD)	15 mg/L
5-day Biochemical Oxygen Demand (BOD5)	3 mg/L

The latest EPD’s water quality index (WQI) indicates that Lam Tsuen River is classed as “Excellent” but Kam Tin River received WQI grading of “Bad” in 2017.

Table 5.2 shows the water quality monitoring data at Lam Tsuen River and Kam Tin River in 2017[1]. The data indicated that the water quality in Lam Tsuen River is still much better than in Kam Tin River, with higher DO but lower SS, BOD5, COD, E. coli and NH₃-N.

Table 5.2 Summary of EPD Water Quality Monitoring Data for Lam Tsuen River and Kam Tin River in 2017

Parameters	TR12H (Lam Tsuen River)	TR12D (Lam Tsuen River)	KT2 (Kam Tin River)
DO (mg/L)	8.4 (7.9 – 9.9)	8.5 (7.9 – 10.0)	5.1 (2.7 – 7.5)
pH	7.2 (6.7 - 7.7)	7.1 (6.9 – 8.0)	7.5 (6.9 - 7.7)
SS (mg/L)	1.4 (0.6 – 28.0)	0.7 (<0.5 – 1.5)	17.0 (4.6 – 74.0)
BOD₅ (mg/L)	0.5 (0.1 – 3.8)	0.4 (0.1 – 2.0)	18.0 (4.9 – 170.0)
COD (mg/L)	<2 (<2 - 12)	<2 (<2 - 6)	28 (11 - 180)
E. coli (counts/100mL)	1 200 (350 – 22 000)	370 (53 – 16 000)	140 000 (13 000 - 590 000)
NH₃-N (mg/L)	0.079 (0.024 - 0.260)	0.017 (0.008 - 0.026)	6.900 (1.300 – 19.000)

Lam Tsuen River recorded a WQOs compliance rate of 95% in 2017. It is due to the continuous enforcement for the WPCO and improved sewerage works for village houses in the area. Domestic, commercial and industrial sewage are directed to the government sewers and transferred to sewage treatment plant before discharge.

For Kam Tin River, the overall compliance rate of the WQOs in 2017 was 60%. This main river was still impacted by discharges from livestock farms, misconnections in old buildings and unsewered premises. However, with the implementation of the Livestock Waste Control Scheme, continuous enforcement for the WPCO, sewage treatment plants and improved sewerage system for village houses, the water quality of the water course is likely to be further improved in the coming years.

5.4 Assessment Methodologies

The assessment area for the water quality impact assessment covers all areas within 500m from the Project Boundary in Deep Bay WCZ and Tolo Harbour and Channel WCZ as designated under the WPCO.

The Water Sensitive Receivers (WSRs) that may be affected by the Project have been identified. These include water gathering ground from the project eastern end, local streams near Kadoorie Experimental Farm, Ling Wan Monastery, Wong Chuk Yuen, Sheung Tsuen and Kam Tin Bypass; nullah near Wang Toi Shan Hung Mo Tam, Shek Kong Barracks and the channelized Kam Tin River. It is noted that there is an encroachment of about 60m of the water gathering zone located at the eastern end of the Project. Locations of the representative WSRs are shown in Figure 5.1.

Terrain in the vicinity of the construction works area varies along the Project road. In general, relatively gentle and plain slope is found at the western part of Kam Tin Road from the road works section near Kam Tin Bypass to the section near Wang Toi Shan Lo Uk Tsuen. The slope of Lam Kam Road inclines upwards towards the east and the altitude of the road is higher than that of the nearby area near Wong Chuk Yuen, and lower than the land on the side of Ling Wan Monastery. Construction sites located at higher altitude may induce potential surface runoff flowing towards the nearby lowland.

Potential sources of water quality impact that may arise during the construction and operation phases of the Project are described as below. All the identified sources of potential water quality impact are evaluated and the impact significance is determined. Mitigation measures are recommended to reduce any identified adverse impacts on water quality to acceptable levels and prevent wastewater generated from construction works from entering Kam Tin River within Deep Bay WCZ and Lam Tsuen River within Tolo Harbour and Channel WCZ.

5.5 Identification and Evaluation of Environmental Impacts

5.5.1 Construction Phase

Potential water quality impact might be arisen from the associated construction works of road widening and improvement works such as retaining wall and geotechnical works. Key water pollution sources include:

• General construction activities and site runoff from wash water from dust suppression measures, vehicle wheel washing facilities and concrete casting;

• Surface runoff from rainfall and wind erosion of exposed surface areas and material stockpiles;

• Spillage of chemicals, lubrication oils, solvent and petroleum products;

• Sewage from the construction workforce; and

• Construction works in close proximity of nearby water bodies

General Construction Activities

General construction activities, including general cleaning and polishing, wheel washing, dust suppression, concrete casting and utility installation, may generate wastewater which would contain high concentration of SS. Various construction works may also generate debris and waste such as packaging, construction materials and general refuse. Uncontrolled discharge of site effluents and waste generated from the construction works would lead to deterioration in water quality. Adoption of the guidelines and good site practices for handling and disposal of construction discharges as specified in Section 5.7 would minimize the potential impacts.

Surface Runoff from Rainfall and Wind Erosion

In particular, surface runoff into receiving water courses during and immediate after rainstorm events is of major concern. During rainstorms, site runoff would wash away the soil particles on unpaved lands and areas with exposed topsoil. Sediment lade runoff and wind-blown dust would result in deteriorating water quality with increase of SS levels and turbidity and may result in induced effects on aquatic ecological resources. It is important that proper site practice and good site management (as specified in the ProPECC PN 1/94 “Construction Site Drainage”) to be followed to prevent site runoff with high level of SS from entering the surrounding waters. With the implementation of appropriate measures to control runoff and drainage from the construction site, disturbance of water bodies would be avoided and deterioration in water quality would be minimal.

Spillage of Chemicals

Accidental spillage and the storage of chemicals used on-site, such as petroleum products, surplus adhesives, spent lubrication oil, grease and mineral oil, spent acid and alkaline solutions/solvent and other chemicals, may contaminate the surface soils. The contaminated soil particles may be washed away by construction site runoff or stormwater drainage and eventually may affect nearby water bodies. The potential impacts could however be mitigated by practical mitigation measures and good site practices as given in Section 5.7.

Sewage from the Construction Workforce

Sewage effluents will arise from the sanitary facilities provided for the on-site construction workforce. The characteristics of sewage would include high levels of BOD₅, Ammonia and E. coli counts. This temporary sewage can be handled by providing adequate portable chemical toilets. Provided that sewage is not discharged directly into storm drains or inland waters adjacent to the construction site, and temporary sanitary facilities are used and properly maintained, it is unlikely that sewage generated from the sites would have a significant water quality impact.

Construction Works in Close Proximity of Nearby Water Bodies

As the Project Boundary fall within about 60m of the water gathering ground located at the eastern end of the Project, some sections of road works would be at close proximity of nearby water bodies. Potential water quality impacts associated with construction works of the Project may be arisen.

There are nine road sections which are adjacent to or even across the existing watercourses, the locations are shown in Figure 2.4. Details of construction works at the road sections can be referred to Section 2.5 of Chapter 2.

Construction activities within or in close vicinity to nearby water bodies may affect the water quality due to potential release of wastewater which is generally with high concentration of SS and elevated pH. Mitigation measures shall be implemented to control the release of wastewater into the adjacent water environment. With proper implementation of appropriate construction runoff control practices as referred to ProPECC PN 1/94 “Construction Site Drainage” and the provision of mitigation measures as described in the ETWB TC (Works) No. 5/2005 “Protection of natural streams/rivers from adverse impacts arising from construction works”, it is anticipated that no unacceptable water quality impacts would be arising from the construction works nearby the water bodies.

5.5.2 Operation Phase

Potential water quality impacts during the operation phase is the road surface runoff. Runoff from paved road surface may be arisen from storm water carrying dissolved and particulate materials including dust, debris, heavy metals and vehicle oil, which are generated from the degradation of the road surface and tyres, corrosion of metal body parts and leakage of fuel, oil, fluid and fine solids of passing vehicles. Materials deposited and accumulated on road surface will be washed from the carriageway during rainfall events into surface water drainage system and discharged to storm drains. In addition, there will be no sewage generation during the operation phase of the Project.

The drainage system along Kam Tin Road and Lam Kam Road will be upgraded to cater for the highway discharge with increased capacity after road widening. The road drainage system will be properly planned to receive road surface runoff at the planning and design stages.

With adequate capacity to collect all surface water and implementation of good management measures as described in Section 5.7.2 below, no adverse impacts associated with the discharge of runoff are anticipated during the operation phase.

5.6 Potential Cumulative Impacts from Concurrent Project

Further to Chapter 2 of this Report, there will be four concurrent projects identified in the vicinity (within 500m from the Project site) during construction phase of the Project.

As all the concurrent projects would be land-based and provided that proper mitigation measures would be proposed in EIA Study/environmental assessments and implemented in future construction phase, only local-scale impacts arising from the construction activities of these projects are anticipated.

Table 5.3 below summarises the potential concurrent projects that would contribute to the cumulative impacts on water quality during construction and/or operation phase.

Table 5.3 Potential Cumulative Water Quality Impacts from Concurrent Project

Concurrent Projects	Project Proponent	Designated Project	Construction Programme	Potential Cumulative Impacts
Concurrent Projects	Project Proponent	Designated Project	Construction Programme	Construction Phase	Operation Phase
Development of Organic Resources Recovery Centre (ORRC) (Phase 3)	EPD	Yes	Tentatively scheduled to commence in 2023 and complete by 2026	Potential water quality impact arisen from site surface runoff from general construction activities and sewage effluent from construction workforce is anticipated. However, the cumulative impact is not able to be taken into account in this study as no detail information, construction methods and activities can be provided from the concurrent project. Nevertheless, according to EIAO, an EIA study of this concurrent project will be conducted, and the cumulative impact will be addressed in the study.	Potential water quality impact of this concurrent project may be arisen from the discharge of stormwater gathered from rainfall events and effluents from operation processes to the drainage and sewerage system. Yet, with the provision of appropriate treatment facilities and re-circulation of process water as recommended in Project Profile (No. PP-552/2017)[2], no cumulative water quality impact is anticipated during operation phase of this concurrent project.
Site Formation and Infrastructure Works for Developments at Kam Tin South, Yuen Long - Advance Works	CEDD	No	Commenced in 2018 and tentatively scheduled to complete by 2021	No cumulative water quality impact as only a works area of minor road junction improvement works located around 300m away from the Project.	Potential water quality impact of this concurrent project would be the surface runoff during rainfall events, which contains vehicle dust, fallen leaves, particles and litter etc. Given that the Best Management Practices (BMPs) and mitigation measures suggested in the Preliminary Environmental Review (PER)[3] is implemented, the potential water quality impacts associated with the storm water discharge would be avoided as far as possible. No cumulative water quality impact is anticipated during operation phase of this concurrent project.
Improvement to Fan Kam Road	HyD	No	The project is still under investigation stage and thus no construction programme is consolidated.	Potential water quality impact arisen from site surface runoff from general construction activities and sewage effluent from construction workforce is anticipated. However, the cumulative impact is not able to be taken into account as no detail information such as design, construction and operation details can be provided from the concurrent project.	Potential water quality impact of this concurrent project would be the surface runoff during rainfall events, which contains vehicle dust, fallen leaves, particles and litter etc. Given that the mitigation measures suggested in the PER[4] is implemented, the potential water quality impacts associated with the storm water discharge would be avoided as far as possible. No cumulative water quality impact is anticipated during operation phase of this concurrent project.
Kam Tin – Pat Heung Sports Centre	LCSD	No	No Construction Programme available as LCSD has not engaged any parties to carry out the investigation for the project.	Potential water quality impact arisen from site surface runoff from general construction activities and sewage effluent from construction workforce is anticipated. However, the cumulative impact is not able to be taken into account as no detail information such as design, construction and operation details can be provided from the concurrent project. Nevertheless, according to ETWB TCW No. 13/2003, a PER study of this concurrent project will be conducted, and the cumulative impact will be addressed in the study.	Potential water quality impact arisen from stormwater and sewage discharge is anticipated. However, the cumulative impact is not able to be taken into account as no detail information such as design, construction and operation details can be provided from the concurrent project. Nevertheless, according to ETWB TCW No. 13/2003, a PER study of this concurrent project will be conducted, and the cumulative impact will be assessed in the study.

5.7 Mitigation of Environmental Impacts

5.7.1 Construction Phase

Dust Suppression

Water used in dust suppression should as far as practicable be re-circulated after sedimentation. When there is a need for final disposal, the wastewater should be leaded to silt removal facilities before being discharged to the storm drain.

Wheel Washing Water

All vehicles and plant should be cleaned before they leave a construction site to minimize the deposition of earth, mud, debris on roads. A wheel washing facility should be provided at every site exit if practicable and wheel-wash overflow shall be directed to silt removal facilities before being discharged to the storm drain. The site boundary between the wheel washing facility and the public road should be placed with sand bunds to prevent wheel-wash overflow from entering public road drains.

Wastewater from Concrete Casting

Wastewater generated from the washing down of mixing trucks and drum mixers and similar equipment should whenever practicable be recycled. The discharge of wastewater should be kept to a minimum. To prevent pollution from wastewater overflow, the pump sump of any water recycling system should be provided with an on-line standby pump of adequate capacity and with automatic alternating devices. Under normal circumstances, surplus wastewater may be discharged into foul sewers after treatment in silt removal.

Rubbish and Litter

Good site practices should be adopted to remove rubbish and litter from construction sites so as to prevent the rubbish and litter from spreading from the works area. It is recommended to clean the construction sites on a regular basis. Adequate refuse collection points shall be provided on-site.

Construction Site Runoff

The site practices outlined in ProPECC PN 1/94 “Construction Site Drainage” should be followed as far as practicable to minimise surface runoff and the chance of erosion. It is expected that the following measures recommended will effectively control runoff from the works sites and avoid water pollution downstream and shall be implemented during construction phase. A schematic diagram illustrating the general drainage design for a work front is given in Figure 5.2.

Surface runoff from construction sites should be discharged into storm drains via sand/silt removal facilities such as sedimentation basin/tank. Earth bunds or waterfilled barriers with geotextile sheet should be provided on site boundaries to intercept surface runoff from outside the site so that it will not wash across the site and to prevent surface runoff flowing out of the site. Bunds or sandbags should also be used within the site to direct surface runoff into the silt removal facilities. Stagnant surface runoff should be pumped to the silt removal facilities before discharged into storm drains.

Manholes (including newly constructed ones) should always be adequately covered and temporarily sealed so as to prevent silt, construction materials or debris from getting into the drainage system without having previously passed through sedimentation tank, and to prevent storm runoff from getting into foul sewers. Discharge of surface runoff into foul sewers must always be prevented in order not to unduly overload the foul sewerage system.

Silt removal facilities and manholes should be maintained and the deposited silt and grit should be removed regularly, at the onset of and after each rainstorm to prevent local flooding.

Surface excavation should be carefully programmed to avoid wet-season operation. If it is unavoidable, any exposed top soils should be covered with a tarpaulin or other means. For the purpose of preventing soil erosion, temporary exposed slope surfaces should be covered e.g. by tarpaulin, as excavation proceeds. Earthworks final surfaces should be well compacted and the subsequent permanent work or surface protection should be carried out immediately after the final surfaces are formed to prevent erosion caused by rainstorms.

Open stockpiles (e.g. aggregates, sand and fill material) should also be covered with a tarpaulin to avoid erosion during rainstorms. The washing of material from the stockpiles directly into the storm drains should be prevented by passing the runoff through sedimentation tank. Arrangements should always be in place in such a way that adequate surface protection measures can be safely carried out well before the arrival of a rainstorm.

Spillage of Chemicals

Chemical waste, as defined under the Waste Disposal (Chemical Waste) (General) Regulation, includes any substance being scrap material, or unwanted substances specified under Schedule 1 of the Regulation. Substances likely to be generated by construction activities arise from the maintenance of construction plant and equipment of the Project. These include, but not limited to the following:

• Lubricating oil and waste fuel (diesel) from construction plant with improper maintenance; and

• Spent solvents from equipment cleaning activities.

Due to the scale of an active work front of the Project, it is anticipated that no maintenance shop for construction plant and equipment would be operated on-site and storage fuel on-site is minimal. Drainage traps such as grease traps and petrol interceptors will be installed at each of the drainage outlets to filter out chemical pollutants from surface runoff.

Mitigation such as providing drip tray/proper storage of chemical containers will be strictly implemented during the construction works. In case of any leakage on bare ground, oil and grease decontamination kit will be available on-site for clean-up of oil leakage. Any fuels should be stored in bunded areas such that spillage can be easily collected. The contractor shall prepare an oil / chemical clean-up plan in the Waste Management Plan before the commencement of construction works. It should ensure that leakages or spillages are contained and cleaned up immediately. Once spillage is identified on-site, the clean-up procedures should be carried out as below:

• Contact the site agent and/or foreman immediately and report the spillage;

• Identify the source of spillage and determine nature of the material;

• Stop leakage immediately where possible;

• Identify all current and potential affected areas according to the flow of spillage and stop the spillage from flowing to other works areas;

• Contain the surface runoff of spillage by using bunds made from available materials;

• After the surface runoff of spillage is contained, remove the materials (including contaminated soil where necessary) using pumps and/or absorbent materials; and

• Dispose of the materials, including the contaminated soil, as chemical waste

Waste oil should be collected and stored for recycling or disposal, in accordance with the Waste Disposal Ordinance (Cap. 354). The contractor must register as a chemical waste producer if chemical wastes would be produced from the construction activities. The Waste Disposal Ordinance (Cap. 354) and its subsidiary regulations in particular the Waste Disposal (Chemical Waste) (General) Regulation, should be observed and complied with for disposal of chemical wastes. The Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes published under the Waste Disposal Ordinance (Cap. 354) details the requirements to deal with chemical wastes. General requirements are given as follows:

• Suitable containers should be used to hold the chemical wastes to avoid leakage or spillage during storage, handling and transport;

• Chemical waste containers should be suitably labelled, to notify and warn the personnel who are handling the wastes, to avoid accidents; and

• Storage area should be selected at a safe location on site and adequate space should be allocated to the storage area

Sewage Effluent from Construction Workforce

Portable chemical toilets would be provided for handling the sewage effluent generated by the workforce. The number of the chemical toilets required for the construction sites would be subject to later detailed design, the capacity of the chemical toilets, and contractor’s site practices. A licensed contractor would be employed to provide appropriate and adequate portable toilets and be responsible for appropriate disposal and maintenance.

Domestic sewage generated by the construction workforce should be appropriately managed to avoid potential adverse impacts of uncontrolled sewage discharge into nearby water courses. Portable chemical toilets shall be appropriately located on-site in proximity to all major works areas where they shall remain and be maintained in good working order for the convenience of the workforce during the construction phase.

The provision of temporary toilet facilities within the water gathering ground, if any, is subject to approval of the Director of Water Supplies. As a minimum requirement, temporary toilet facilities must be located more than 30m from any watercourse.

Notices would be posted at conspicuous locations to remind the workers not to discharge any sewage or wastewater into the nearby environment during the construction phase of the Project. Regular environmental audit on the construction site would be conducted in order to provide an effective control of any malpractices and achieve continual improvement of environmental performance on site.

Construction Works in Close Proximity of Nearby Water Bodies

The practices outlined in ETWB TC (Works) No. 5/2005 “Protection of natural streams/rivers from adverse impacts arising from construction works” should also be adopted where applicable to minimize the water quality impacts upon any natural streams or surface water systems. Relevant mitigation measures from the ETWB TC (Works) No. 5/2005 are listed below:

• Construction works close to the inland waters should be carried out in dry season as far as practicable where the flow in the surface channel or stream is low.

• The use of less or smaller construction plants may be specified in areas close to the water courses to reduce the disturbance to the surface water.

• Temporary storage of materials (e.g. equipment, chemicals and fuel) and temporary stockpile of construction materials should be located well away from any water courses during carrying out of the construction works.

• Stockpiling of construction materials and dusty materials should be covered and located away from any water courses.

• Construction debris and spoil should be covered up and/or disposed of as soon as possible to avoid being washed into the nearby water receivers.

• Proper shoring may need to be erected in order to prevent soil or mud from slipping into the watercourses.

• Fencing should be erected on the sides facing the nearest stream course to trap all wind-blown litters such as paper, plastic bags, bottles and boxes within the site from entering the nearby water bodies.

• The proposed works site inside or in the proximity of natural rivers and streams should be temporarily isolated, such as by placing of cofferdam with silt curtain with lead edge at bottom and properly supported props, to prevent adverse impacts on the stream water qualities. Other protective measures should also be taken to ensure that no pollution or siltation occurs to the water gathering grounds of the work site.

• The natural bottom and existing flow in the river should be preserved as much as possible to avoid disturbance to the river habitats. If temporary access track on riverbed is unavoidable, this should be kept to the minimum width and length. Temporary river crossings should be supported on stilts above the riverbed.

The contractor shall also comply with the “Condition of Working within Water Gathering Ground” during Project construction. The guideline is attached in Appendix 5.1. Any effluent discharged from the proposed development at points within gathering grounds should comply fully at all times with standards for effluents stipulated in Table 2 and paragraph 8.4 of the “Technical Memorandum on Effluent Standards” issued under section 21 of the WPCO.

5.7.2 Operation Phase

Road gullies should be provided to direct and collect all surface runoff to the drainage system. The capacity should be properly designed to cater for all surface water.

Road gullies with standard design should be incorporated during the detailed design to remove particles present in stormwater runoff. Screening facility such as standard gully grating, with spacing which is capable of screening off large substances such as fallen leaves and rubbish should be provided at the inlet of drainage system.

Road drains should be properly maintained and cleaned regularly to ensure good service condition. Good management measures such as regular cleaning of road gullies and sweeping of road surface should be carried out prior to occurrence of rainstorm.

5.8 Environmental Monitoring and Audit

There will be construction works in close proximity of nearby water bodies: watercourse (meander) adjacent to north of section between Chainage CHA 8+00 to CHA 9+10 of Kam Tin Road, watercourse across road section between Chainage CHB 41+10 to CHB 41+30 of Lam Kam Road, and watercourse across road section between Chainage CHB 48+85 to CHB 49+15 of Lam Kam Road. Yet, no significant water quality impacts are expected during the construction and operation phases given that the proposed mitigation measures are properly implemented. Water quality monitoring is not considered necessary, however, regular site inspections are recommended to be conducted during construction phase in order to ensure the mitigation measures are implemented properly. Any effluent discharges from the site would be required to comply with the terms and conditions of a discharge license to be applied as necessary under the WPCO.

5.9 Conclusion

Given both magnitude and duration of works and with the implementation of the mitigation measures during the construction phase, no significant water quality impacts are anticipated for the Project. The implementation of the mitigation measures shall be included to the works contracts. Regular site inspections are recommended during construction phase to ensure the measures are implemented properly.

During the operation phase, the stormwater from the surface runoff is the key identified environmental impact and there will be no sewage generation during Project operation. Road drainage system along Kam Tin Road and Lam Kam Road will be properly planned and upgraded to cater for the road surface runoff from highway with increased capacity after road widening. With the mitigation measures mentioned in Section 5.7.2 in place, residual adverse water quality impacts are not anticipated.

[1] River Water Quality in Hong Kong in 2017, published by EPD.

[2] Project Profile of Development of Organic Resources Recovery Centre (Phase 3) (No. PP-552/2017)

[3] Preliminary Environmental Review Report (Final) for Agreement No. CE 34/2014 (CE) Site Formation and Infrastructural Works for the Initial Sites at Kam Tin South, Yuen Long – Investigation, Design and Construction

[4] Report on Preliminary Environmental Review (Final) for Agreement No. CE 61/2012 (HY) Improvement to Fan Kam Road – Investigation