1                     Introduction

 

1.1               The pollution loading inventory was compiled for the storm and sewage outfalls within the whole Hong Kong waters for input into the Update Model and the HATS Model for four time horizons, namely 2009, 2013, 2020 and Ultimate Year respectively, for cumulative impact assessment.  The methodologies for compiling the pollution loading are given in this Appendix.

 

2                     Storm Outfalls     

 

2.1               The key sources of water pollution in storm outfalls include:

 

l          Pollution due to sewage from unsewered developments (dry weather load)

l          Pollution due to expedient connections from trade and residential premises, and integrity problems of aged drainage and sewerage systems (dry weather load)

l          Pollution due to livestock waste (dry weather load)

l          Rainfall related load.

 

2.2               The total pollution load discharged via the storm system would cover the dry weather load and rainfall related load

 

Dry Weather Load

 

2.3               Domestic, commercial and industrial activities are the principle sources of dry weather load in storm drains.   Total pollution loads generated from these activities were compiled by catchment areas as shown in Figure A5-2-1 below with reference to the projected population and employment data provided by the Planning Department (PlanD).  Details of these planning data and the methodology for calculating the pollution loads from domestic commercial and industrial activities are given in Section 4 of this Appendix.

 

2.4               It was assumed that a portion of total pollution load generated within a catchment would be lost to the storm system whilst the rest of the flow would be diverted to the sewerage system.  The assumed percentages of pollution load discharged into the storm system for different catchments are presented in Table A5-2-1.

Figure A5-2-1 Sewage Catchment Boundaries

 

 

Table A5-2-1 Assumed % of Pollution Load in the Storm System for 2009, 2013, 2020 and Ultimate Year

Catchment

Catchment ID

Assumed % of Load in the Storm System

Foul interception to:

2009

2013 / 2020 / Ultimate Year

2009

2013 / 2020 / Ultimate Year

Sai Kung

1

10%

10%

Sai Kung STW

Sai Kung Country Park

1a

100%

50%

Pak Sha Wan

1b

10%

10%

Clear Water Bay

1c

100%

100%

-

Tseung Kwan O

2

5%

5%

HATS

Yau Tong, East Kowloon

4

10%

10%

North Kowloon, Central Kowloon, South Kowloon

5

10%

10%

Northwest Kowloon

8

10%

10%

Stonecutters

9a

10%

10%

Kwai Chung and Tsuen Wan East

10a

10%

10%

Tsing Yi

10b

10%

10%

Tsuen Wan West (Rural Area)

11

10%

10%

Sham Tseng STW

Tuen Mun

12

10%

10%

Pillar Point STW

Yuen Long and Tin Shui Wai and Deep Bay Streams

12a

10%

10%

San Wan STW

Kam Tin and Yuen Long New Town

12d

10%

10%

Yuen Long STW

Discovery Bay

13

0%

0%

Siu Ho Wan STW

North Lantau

13a

10%

10%

Chek Lap Kok

13b

0%

0%

Peng Chau

14

50%

30%

Peng Chau STW

Mui Wo

15

10%

10%

Mui Wo STW

South Lantau

15a

100%

100%

-

Hei Ling Chau

16

0%

0%

Hei Ling Chau STW

Cheung Chau

17

30%

30%

Cheung Chau STW

Shek Kwu Chau

17a

100%

100%

-

Tai A Chau

17b

0%

0%

Tai A Chau PTW

Shek Pik

18

10%

10%

Shek Pik STW

Tai O

18a

10%

10%

Tai O STW

Lamma Island

19

30%

30%

Yung Shue Wan STW and Sok Kwu Wan STW

Poi Toi Islands

19a

100%

100%

-

Tung Lung

19b

100%

100%

-

Pokfulam Sandy Bay

20a

10%

10%

Sandy Bay PTW

HATS

Cyber Port

20b

10%

10%

Cyber Port STW

HATS

Wah Fu Estates and Mt. Kellet

21

10%

10%

Wah Fu PTW

HATS

Aberdeen, Shouson Hill and Repulse Bay, South Bay

22

10%

10%

Aberdeen PTW

HATS

Ap Lei Chau

23

10%

10%

Ap Lei Chau PTW

HATS

Chung Hom Kok

26

10%

10%

Stanley STW

Stanley

27

10%

10%

Tai Lam

28

10%

10%

Shek O

29

10%

10%

Shek O STW

Chai Wan

30

10%

10%

HATS

Shau Kei Wan

31

10%

10%

North Point

32

10%

10%

North Point PTW

HATS

Wan Chai East

33

10%

10%

Wan Chai East PTW

HATS

 

Wan Chai West

34

10%

10%

Western and Central, Green Island

35

10%

10%

Central PTW

HATS

Tolo Harbour

37

10%

10%

THEES

Sheung Shui and Fanling

38

10%

10%

Shek Wo Hui STW

North New Territories

39

95%

95%

Sha Tau Kok

40

10%

10%

Sha Tau Kok STW

 

2.5               The percentage interceptions assumed in Table A5-2-1 were based on the implementation schedule for sewerage improvement projects as adopted under the EEFS.  A detailed review on the sewage discharges from Tsuen Wan West (Rural Area) catchment was conducted under this EIA, given their significance to the water quality at Tsuen Wan coast including the eight beaches in the Tsuen Wan District.  It is expected that sewerage along the Castle Peak Road would be in place before commissioning of this ADF Project to serve unsewered village and properties around Ting Kau, Sham Tseng and Tsing Lung Tau.  Based on the information obtained from IPG of EPD, the % of population within the Tsuen Wan West catchment that would be connected to the STW would be about 95% in 2009.  However, for conservative assessment, it was assumed that only 90% of the total sewage flow generated in the catchment would be connected to the STW as a base case for water quality modelling under the 2009, 2013, 2020 and ultimate scenarios.

 

2.6               The pollution loading in the storm system contributed from domestic, commercial and industrial activities was compiled to the catchment levels shown in Figure A5-2-1. The pollution loading compiled for each catchment was distributed to appropriate discharge points (i.e. storm culverts / outfalls, rivers and nullahs).  It was assumed that these storm pollutions would be evenly distributed amongst the major storm water discharge points within the catchment.

 

2.7               The livestock waste load discharged via rivers / streams adopted under the EEFS as shown in Table A5-2-2 was directly applied in this EIA for 2009, 2013, 2020 and ultimate year. 

 

Table A5-2-2 Livestock Waste Load Assumed for 2009, 2013, 2020 and Ultimate Year

Catchment

River Name

Flow (m3/d)

SS (kg/d)

TKN (kg/d)

NH3-N (kg/d)

TP (kg/d)

E.coli (counts/d)

Tsueng Kwan O

Tseng Lan Shue River

2

0

0

0

0

6.98E+11

Sheung Shui and Fanling

Shenzhen River

3216

363

41

22

18

9.28E+14

Yuen Long, Tin Shui Wai and Kam Tin

Shan Pui Ho River

5034

568

65

34

28

1.45E+15

Tin Shui Wai Nullah

4190

473

54

28

24

1.21E+15

Deep Bay

Sheung Pak Nai Stream

97

11

1

1

1

2.79E+13

Ha Pak Nai Stream

677

76

9

5

4

1.95E+14

 

2.8               The total dry weather load in the storm outfall would include the loading contributed from domestic, commercial and industrial activities and the loading from livestock discharges (if any) as shown in Table A5-2-2.

 

Rainfall Related Load

 

2.9               It was assumed that a rainfall volume of greater than 10mm per day (and rainfall intensity greater than 2mm/hr) would give rise to runoff.  The runoff percentage was based on the average rainfall data between 1/01/74 and 31/10/05 from the Hong Kong Observatory.  The calculation of the runoff percentage is shown below:

 

Runoff percentage = (Sum of the rainfall volume for the days with rainfall volume > 10mm and intensity > 2mm/hr within the season) ¸ Total rainfall volume for the season x 100%

 

2.10            Rainfall data from May to September represent the values for wet season, and those from November to March represent the values for dry season. Accordingly, the runoff percentage was calculated as 93% and 70% for wet and dry seasons respectively

.

2.11            The 30-year long term average rainfall data were used to determine the daily runoff value as shown below:

 

Daily runoff value (m/day) = 30year long term average daily rainfall data x runoff percentage

 

2.12            Thus, the runoff value was calculated as 0.01104 m/day and 0.00102 m/day for wet and dry seasons respectively.

 

2.13            The amount of rainfall related load that would be discharged into the sea depends on the amount of impermeable area within each catchment.  It was assumed that all urbanized/developed areas within the catchment would be impermeable.  The daily volume of runoff generated within each catchment was estimated as shown below:

 

Daily volume of runoff in each catchment (m3/day)

= daily runoff value (m/day) x impermeable area within each catchment (m2)

 

2.14            The daily volume of runoff estimated for each catchment was multiplied with the runoff concentrations to derive the rainfall related loading.  The assumed runoff concentrations are shown in Table A5-2-3.

     

Table A5-2-3 Event Mean Concentrations for Stormwater Runoff

TSS

(g/m3)

BOD5

 (g/m3)

NH3N

(g/m3)

Cu

(g/m3)

TP (g/m3)

OrthoP (g/m3)

Silicate (g/m3)

TON

(g/m3)

TKN

(g/m3)

43.25

22.48

0.20

0.01

0.20

0.04

3.28

0.40

1.40

Source of reference: EPD Pilot Study of Storm Pollution

 

2.15            The rainfall related loading was compiled to the catchment levels shown in Figure A5-2-1. The pollution loading compiled for each catchment was distributed to appropriate discharge points (i.e. culverts, outfalls, rivers and nullahs).  It was assumed that the rainfall related loading was evenly distributed amongst the major storm water discharge points within the catchment.   

 

3                     Sewage Outfalls

 

3.1               A portion of the total loads from domestic, commercial and industrial activities generated in each catchment was allocated to the sewerage system according to the percentage of storm interception shown in Table A5-2-1. The remaining portion of the total load in each catchment was distributed to the storm system.

 

3.2               Besides the pollution loads from domestic, commercial and industrial activities, the sewerage system would also receive pollution loads from landfills and beaches as most of the landfill sites and beach facilities would be connected to the sewerage system. Table A5-2-4 and Table A5-2-5 show the pollution load of relevant landfills and beaches adopted under the EEFS. These loading data were directly adopted in this EIA for 2009, 2013, 2020 and ultimate scenarios. The beach loading was included for the wet season simulations only.  Loading from landfills and beaches that would not be connected to the STW is given in Section 6 of this Appendix.  It is considered that the effect of this point source pollution loading would be localized.  As indicated in Section 7 of this Appendix, contributions of these point source pollution loads would be insignificant as compared to the overall pollution loading that would be discharged into the sea.  Possible change of these point source loads would unlikely affect the overall modelling results. Thus, the broad assumption of using the same amount of point source pollution loads for all the assessment years is considered acceptable.

 

Table A5-2-4 Pollution Flows and Loads from Landfills

 

 

Discharge Location

Flow (m3/d)

BOD

(kg/d)

SS

(kg/d)

Org-N (kg/d)

NH3-N

(kg/d)

E-Coli (no./d)

Cu

(g/d)

Shuen Wan Landfill

Shuen Wan Landfill

Foul sewer to Tai Po STW

110

8

28

13

76

7.65E+05

2

NEW Strategic Landfills

WENT

Foul sewer to NWNT sewage outfall

714

2648

288

190

1690

4.97E+06

14

SENT

Foul sewer to HATS

523

30

131

26

1

3.64E+06

10

NENT

Foul sewer to Shek Wu Hui STW

541

11

53

22

1

3.76E+06

11

NWNT Landfills

Pillar Point Valley

Foul sewer to Pillar Point STW

3283

3165

822

389

2511

2.28E+07

66

Ngau Tam Mei

 

Foul sewer to HATS

 

200

 

193

 

50

 

24

 

153

 

1.39E+06

 

4

Siu Lang Shui

Gin Drinkers Bay

Ma Tso Lung

Urban Landfills

Jordan Valley

 

Foul sewer to HATS

 

638

 

615

 

160

 

76

 

488

 

4.44E+06

 

13

Ma Yau Tong Central

Sai Tso Wan

Ma Yau Tong West

Ngau Chi Wan

TKO Landfills

TKO I

Foul sewer to HATS

 

69

66

32

8

52

4.77E+05

1

 

Table A5-2-5 Pollution Loads from Beach Users in Bathing Season

Gazetted Beach

Discharge Location

Flow

(m3/day)

BOD

(g/day)

SS

(g/day)

Org-N

(g/day)

NH3-N

(g/day)

E.coli.

(no./day)

TP

(g/day)

OrthoP

(g/day)

Big Wave Bay

Shek O STW

3

788

657

432

985

1.04E+13

224

133

Hairpin

1

334

278

183

417

4.41E+12

95

57

Shek O

20

4895

4079

2685

6118

6.46E+13

1393

829

Deep Water Bay

Aberdeen STW for 2009 and HATS for 2014/20XX

22

5436

4530

2982

6795

7.17E+13

1547

921

Middle Bay

3

667

556

366

833

8.80E+12

190

113

Repulse Bay

44

10968

9140

6017

13710

1.45E+14

3121

1858

South Bay

2

584

487

321

730

7.71E+12

166

99

Chung Hom Kok

Stanley STW

1

225

187

123

281

2.96E+12

64

38

St. Stephen’s

4

875

729

480

1094

1.15E+13

249

148

Stanley Main

6

1504

1254

825

1880

1.98E+13

428

255

Turtle Cove

1

268

223

147

334

3.53E+12

76

45

Silvermine Bay

Mui Wo STW

0

112

93

61

140

1.47E+12

32

19

Hung Shing Yeh

Yung Shue Wan STW

1

308

256

169

384

4.06E+12

88

52

Lo So Shing

0

68

57

37

85

8.99E+11

19

12

Kwun Yau Wan

Cheung Chau STW

0

94

78

52

117

1.24E+12

27

16

Tung Wan, Cheung Chau

4

1089

908

598

1362

1.44E+13

310

185

Silverstrand

Sai Kung STW

18

4556

3797

2500

5695

6.01E+13

1297

772

Trio (Hebe Haven)

3

632

527

347

790

8.34E+12

180

107

Anglers’ **

Sham Tseng STW

0

87

73

48

109

1.15E+12

25

15

Approach **

Sham Tseng STW

0

77

64

42

96

1.02E+12

22

13

Casam **

Sham Tseng STW

0

63

53

35

79

8.36E+11

18

11

Gemini **

Sham Tseng STW

0

41

34

23

52

5.44E+11

12

7

Hoi Mei Wan **

Sham Tseng STW

0

85

71

47

107

1.13E+12

24

14

Lido **

Sham Tseng STW

3

662

552

363

828

8.74E+12

188

112

Ting Kau **

Sham Tseng STW

0

26

22

14

32

3.42E+11

7

4

Butterfly

Pillar Point STW

17

4248

3540

2331

5310

5.61E+13

1209

720

Castle Peak

2

605

504

332

756

7.98E+12

172

102

Kadoorie

22

5561

4634

3051

6951

7.34E+13

1582

942

New Cafeteria

8

2045

1704

1122

2556

2.70E+13

582

346

Old Cafeteria

3

732

610

401

915

9.65E+12

208

124

Golden Beach

22

5505

4587

3020

6881

7.26E+13

1566

932

Note:

**   The beach attendance may be increased in case the beach is re-opened during the ADF stage. Based on the information provided by DSD and EPD, the beach facilities would be connected to Sham Tseng STW during the ADF stage by 2009.  It is considered that the effect from the increase in the loading from Sham Tseng STW due to possible increase in the beach loading on the overall water quality modelling results would be negligible.

 

3.3               The total load generated in the sewerage system would be reduced after the treatment processes. Table A5-2-6 shows the treatment processes for major STW.  It should be noted that SCISTW, Pillar Point Sewage Treatment Works (PPSTW), Siu Ho Wan Sewage Treatment Works (SHWSTW), Tolo Harbour Effluent Export Scheme (THEES), North West New Territories (NWNT) outfall and Sham Tseng Sewage treatment Works (SHTSTW) are not included in Table A5-2-6 as the methodologies for compiling the loading discharged from these STW are discussed separately in Section 5 of this Appendix.  The treatment efficiencies for different treatment processes are given in Table A5-2-7 for reference.

 

Table A5-2-6   Summary of Major Sewage Treatment Works and the Corresponding Treatment Levels

STW

Treatment Level

2009 and 2013

2020 and ultimate year

Stanley

Secondary treatment with disinfection

Secondary treatment with disinfection

Shek O

Preliminary treatment

Preliminary treatment

Tai O

Primary treatment

Primary treatment

Cheung Chau

Primary treatment

Primary treatment

Mui Wo

Secondary treatment with disinfection

Secondary treatment with disinfection

Peng Chau

Secondary treatment with disinfection

Secondary treatment with disinfection

Shek Wu Hui

Secondary treatment with disinfection

Secondary treatment with disinfection

Sha Tau Kok

Secondary treatment with disinfection

Secondary treatment with disinfection

Sai Kung

Secondary treatment with disinfection

Secondary treatment with disinfection

Yung Shue Wan

Secondary treatment with disinfection

Secondary treatment with disinfection

Sok Kwu Wan

Secondary treatment with disinfection

Secondary treatment with disinfection

Hei Ling Chau

Secondary treatment with disinfection

Secondary treatment with disinfection

Shek Pik

Secondary treatment with disinfection

Secondary treatment with disinfection

Cyber Port

Chemically enhanced primary treatment

See Note 1

Note 1 - Effluent from Cyber Port STW would be discharged to the HATS under Stage 2A by 2014.

 

Table A5-2-7 Treatment Efficiency for Treatment Works

Types of Treatment Plant

BOD5

TSS

NH3-N

Org-N

OrthoP

TP

Cu

E.coli

Screening PlantsA

0%

0%

0%

0%

0%

0%

0%

0%

Primary Treatment (no disinfection)

32.5%

55%

0%

15%

0%

15%

26%

50%

Primary Treatment (with disinfection)

32.5%

55%

0%

15%

0%

15%

26%

99.95%

Chemical Enhanced Primary Treatment (with no disinfection)B

55%

70%

10%

45%C

60%

60%

80%

50%

Chemical Enhanced Primary Treatment (with disinfection)B

55%

70%

10%

45%C

60%

60%

80%

99.95%

Secondary Treatment (no disinfection)

85%

90%

75%

80%

35%

50%

74%

94%

Secondary Treatment (with disinfection)

85%

90%

75%

80%

35%

50%

74%

99.97%

Note

A.    It is assumed that the reduction of the pollution parameters is insignificant in screening plants. Therefore, the removal rates for these parameters were all assumed zero.

B.    Based on estimation from the SSDS EIA Study: Technical Note 1 (Revised) Wastewater Flows and Loads and Effluent Characteristics.

C.     The removal rate of org-N is calculated from the removal rates of NH3-N and total N (10% and 25% respectively) assuming that NH3-N contributes about 57% of total N in raw sewage.

 

4                     Pollution Loads from Domestic, Commercial and Industrial Activities

 

Population and Employment Statistics

 

Time Aspect

 

4.1               The 2003-based Territorial Population and Employment Data Matrices (TPEDM) provided by PlanD were used to compile the pollution loads from domestic, commercial and industrial activities.  The TPEDM provides the projected population breakdown by Planning Vision and Strategy (PVS) zones for 2006, 2011 and 2016. For strategic planning purposes, two different scenarios of growth rate are postulated for future population (2011 and 2016) under the 2003-based TPEPM.  Scenario I assumed a total population of 7.57 million by 2016.  Scenario II assumed a total population of 7.94 million by 2016, which represents about 5% increase in population on top of Scenario I.  The population and employment projections for 2006 are only available for Scenario I.

 

4.2               Territorial population projections given by the Census & Statistics Department (C&SD) were used as the control totals for the TPEDM Scenario I.  The TPEDM Scenario II was compiled for long-term planning purposes with no given territorial population as the control totals and was used in this EIA for conservative assessment.

 

4.3               Based on the population projections released by C&SD in June 2004, the Hong Kong resident population is projected to increase from 6.80 million in mid-2003 to 8.38 million in mid-2033. Table A5-2-8 shows the annual population growth rates between mid-2006 and mid-2016 estimated from the C&SD data. There would be no significant variation in the annual growth rates from 2006 to 2016 (ranged from 0.81% to 0.93%).  With an increased number of deaths upon aging of the population, the annual growth rate is expected to slacken to 0.4% towards the end of the projection period (2003-2033).  It should be noted that the pollution loading was compiled using the 2003-based TPEDM provided by PlanD. The C&SD data provided in Table A5-2-8 were solely used as a reference to illustrate the population growth rate.

 

Table A5-2-8 Annual Growth Rate of Hong Kong Population

Year

Annual Growth Rate

Mid-2007

0.81% (between mid-2006 and mid-2007)

Mid-2008

0.90% (between mid-2007 and mid-2008)

Mid-2009

0.91% (between mid-2008 and mid-2009)

Mid-2010

0.92% (between mid-2009 and mid-2010)

Mid-2011

0.93% (between mid-2010 and mid-2011)

Mid-2012

0.91% (between mid-2011 and mid-2012)

Mid-2013

0.89% (between mid-2012 and mid-2013)

Mid-2014

0.85% (between mid-2013 and mid-2014)

Mid-2015

0.83% (between mid-2014 and mid-2015)

Mid-2016

0.81% (between mid-2015 and mid-2016)

 

4.4               The modeling work was carried out for four time horizons, namely 2009, 2013, 2020 and ultimate scenarios. However, the projected population data provided by PlanD at PVS zones are only available for 2006, 2011 and 2016.  The population for 2009 was calculated using the TPEDM Scenario I for 2006 and TPEDM Scenario II for 2011 assuming a constant population growth between 2006 and 2011.  The population for 2013 was calculated using the TPEDM Scenario II for 2011 and TPEDM Scenario II for 2016 assuming a constant population growth between 2011 and 2016. For the ultimate scenario, the 2000-based Year X population data adopted in the EEFS were used for the HATS catchments. For the purpose of this EIA, the ultimate population for the non-HATS catchments was estimated based on a 10% extrapolation of the 2016 data from the 2003-based TPEDM Scenario II. The population for 2020 was calculated using the ultimate population and the 2016 population from the 2003-based TPEDM Scenario II assuming that the ultimate year represents 2030 and a constant population growth between 2016 and 2030.

 

Spatial Aspect

 

4.5               To facilitate the estimation of pollution loading, the population and employment data are required to be presented at the level of catchment areas shown in Figure A5-2-1 of this Appendix. However, the projected population from PlanD is provided in a much smaller scale at PVS zones. Population and employment data for each sewage catchment area were estimated by overlaying the PVS zones on top of the layout of the sewage catchment area for allocating the appropriate PVS zones to the sewage catchment area.  

 

Data Manipulation

 

4.6               The TPEDM provides the number of usual residents, mobile residents and school places within the territory at PVS zones.

 

4.7               Employment population is divided by 12 job types under the TPEDM as listed below:

 

l          J1   Manufacture

l          J2   Electricity, gas & water

l          J3   Transport, storage & communication

l          J4   Wholesale and retail

l          J5   Import & export

l          J6   Financial, insurance, real estate & business services

l          J7   Agriculture & fishery

l          J8   Mining & quarrying

l          J9   Construction

l          J10 Restaurants, hotels & boarding houses

l          J11 Community, social & personal services

l          J12 Public administration

 

4.8               The population data from the TPEDM were manipulated and presented at the following categories:

 

l          Residential population (by usual residents and mobile residents)

l          Transient Population (by total employment number and total school places), where total employment =J1+J2+J3+J4+J5+J6+J7+J8+J9+J10+J11+J12

l          Number of employees in commercial sector (by J2, J3, J4, J9, J10 & J11)

l          Number of employees in manufacturing sector (=J1) by 6 sub-categories, namely food, textiles, leather, paper, manufacturing and machinery respectively.

 

4.9               The domestic pollution load to be generated from a catchment would be affected by the number of resident population and transient population within the catchment.  The total employee number comprises 12 job types listed above. It is considered that commercial effluents are contributed from job J2 to J4 and J9 to J11. Industrial effluents are contributed from job type J1.

 

4.10            In order to provide a better estimation of pollution loads from industrial processes, the number of employees in manufacturing sector (J1) was further broken down into 6 sub-categories, namely food, textiles, leather, paper, manufacturing and machinery.  Projected employment statistics are not available for these 6 sub-categories.  It is noted that the size for each of these 6 sub-categories was estimated under the EPD Update Study. To estimate the size of these 6 sub-categories for this EIA, it is assumed that the share of each sub-category in the manufacturing sector provided in the Update Study would be the same as that for 2009, 2013, 2020 and ultimate year.  Table A5-2-9 to Table A5-2-12 show the population and employment statistics compiled by sewage catchment areas.


Table A5-2-9 Population and Employment for Year 2009

ID

Sewage Catchment Area

Residential Population

School

Total Employment Number

Total Employment in Commercial Activities

Manufacturing Industries

Land Usual Residents

Mobile Residents

Total

Full-Time School Places

Food

Textile

Leather

Paper

Manufacturing

Machinery

Others

Total

1

Sai Kung

 

5010

158

5168

970

1599

1240

7

0

0

0

9

3

8

28

2

Tseung Kwan O

HATS

422567

10672

433240

62843

99564

75867

743

121

0

272

1580

194

7726

10636

4

Yau Tong, East Kowloon

HATS

737385

21613

758998

116931

353487

189718

477

520

37

208

175

1102

10032

12551

5

North Kowloon, Central Kowloon, South Kowloon

HATS

524573

16838

541411

107106

391976

219967

1166

383

34

60

121

413

12407

14584

8

Northwest Kowloon

HATS

787442

29770

817212

194070

482079

306872

623

338

28

95

97

929

8054

10164

9A

Stonecutters Island

HATS

5929

168

6098

325

2632

2117

27

4

14

1

16

18

26

106

11

Tsuen Wan West (Rural Area)

 

30808

1464

32273

468

8153

6122

881

0

0

0

5

1

13

900

12

Tuen Mun

 

512707

14959

527666

98324

127874

92089

943

505

27

29

543

667

7951

10665

13

Discovery Bay

 

15534

405

15939

1780

4614

3829

0

0

0

0

0

0

32

32

14

Peng Chau

 

2523

13

2536

203

569

270

0

0

0

0

0

0

4

4

15

Mui Wo

 

7151

133

7284

1032

3017

2307

0

0

0

0

0

2

17

19

16

Hei Ling Chau

 

5070

25

5096

409

1144

543

2

0

1

0

1

1

2

9

17

Cheung Chau

 

22052

239

22291

4823

5768

3935

25

4

0

3

1

9

60

100

18

Shek Pik

 

1766

12

1778

289

677

367

6

0

0

0

0

0

0

6

19

Lamma Island

 

5723

83

5806

342

2147

1903

11

0

0

1

14

0

0

26

20A

Pokfulam Sanday Bay

 

7558

339

7898

4271

6765

6216

11

0

0

1

2

1

19

33

20B

Cyber Port

 

14811

742

15553

1852

7093

5209

35

0

0

3

7

2

61

109

21

Wah Fu Estates and Mt. Kellet

 

39715

1223

40937

7417

7617

6351

0

0

0

0

20

0

45

65

22

Aberdeen , Shouson Hill and Repulse Bay, South Bay

 

125371

3729

129100

28649

57302

37202

358

8

2

91

216

108

1979

2761

23

Ap Lei Chau

 

85855

1766

87621

8734

20755

16822

127

1

0

2

99

29

374

632

26

Chung Hom Kok

 

1582

50

1632

271

563

380

0

0

0

0

0

0

3

3

27

Stanley

 

15146

478

15624

2438

5218

3415

0

0

0

0

0

0

26

26

28

Tai Tam

 

4310

120

4430

1455

1713

1391

0

0

0

0

0

3

9

12

29

Shek O

 

15036

521

15557

3117

7456

3968

998

0

0

0

0

0

0

998

30

Chai Wan

HATS

158022

4901

162922

31159

66715

38906

499

102

25

441

236

417

4845

6565

31

Shau Kei Wan

HATS

181611

5918

187529

22562

59676

36325

55

3

1

49

44

145

868

1166

32

North Point

 

230402

10034

240436

50502

168137

89965

405

19

6

928

442

316

5355

7473

33

Wan Chai East

 

83697

3932

87629

27450

137049

75314

95

29

0

215

63

74

1157

1632

34

Wan Chai West

 

66041

2976

69017

17884

255792

91859

145

6

0

241

181

402

1832

2807

35

Western and Central, Green Island

 

211601

6510

218112

45625

219846

102576

793

19

15

166

264

107

3409

4773

37

Tolo Harbour

 

962666

31355

994021

193227

314392

211313

2921

82

10

135

520

1085

14782

19536

38

Sheung Shui and Fanling

 

297215

9867

307082

57214

73554

52486

596

60

14

39

315

391

2684

4099

39

North New Territories

 

15297

258

15554

793

5797

2694

20

2

4

3

50

62

188

330

40

Sha Tau Kok

 

9413

238

9651

1226

2252

1355

29

1

0

16

7

6

16

75

10A

Kwai Chung and Tsuen Wan East

HATS

546423

18014

564437

95019

325482

167089

892

1238

96

195

596

1776

21421

26214

10B

Tsing Yi

HATS

192829

6503

199332

28830

43769

32444

47

72

0

2

127

64

1854

2168

12A

Yuen Long and Tin Shui Wai and Deepbay Streams

 

453869

13399

467269

83348

99749

76524

1123

93

0

41

284

406

1842

3790

12D

Yuen Long New Town and Kam Tin

 

134035

4058

138093

17197

35973

25337

878

0

29

0

260

396

2557

4120

13A

North Lantau

 

104051

4268

108319

15589

37385

33798

10

1

5

1

6

7

851

880

13B

Chek Lap Kok

 

2

0

2

0

52442

33949

0

0

0

0

6841

0

0

6841

15A

South Lantau

 

3074

25

3099

493

1074

597

0

0

0

0

0

1

9

10

17A

Shek Kwu Chau

 

142

1

143

23

54

29

0

0

0

0

0

0

0

0

17B

Tai A Chau

 

142

1

143

23

54

29

0

0

0

0

0

0

0

0

18A

Tai O

 

3049

21

3069

499

1168

633

6

0

0

0

0

0

5

11

19A

Poi Toi Islands

 

79

0

79

0

24

9

0

0

0

0

0

0

0

0

19B

Tung Lung

 

1094

44

1138

129

263

222

0

0

0

0

0

0

0

0

1A

Sai Kung Country Park

 

38454

1121

39576

7211

14438

10937

79

0

0

0

0

4

183

266

1B

Pak Sha Wan

 

35499

1249

36748

6645

7637

6214

37

0

0

0

5

7

56

105

1C

Clear Water Bay

 

3952

160

4111

464

951

802

0

0

0

0

0

0

4

4

 


Table A5-2-10 Population and Employment for Year 2013

ID

Sewage Catchment Area

Residential Population

School

Total Employment Number

Total Employment in Commercial Activities

Manufacturing Industries

Land Usual Residents

Mobile Residents

Total

Full-Time School Places

Food

Textile

Leather

Paper

Manufacturing

Machinery

Others

Total

1

Sai Kung

 

5182

176

5358

977

1710

1337

8

0

0

0

10

3

9

30

2

Tseung Kwan O

HATS

449817

11863

461680

63536

114532

86639

846

138

0

310

1799

221

8799

12113

4

Yau Tong, East Kowloon

HATS

769324

24055

793379

116911

385856

207599

274

299

21

120

101

633

5766

7213

5

North Kowloon, Central Kowloon, South Kowloon

HATS

569994

19607

589600

107677

419142

237006

960

315

28

49

100

340

10216

12008

8

Northwest Kowloon

HATS

842577

34675

877251

195178

503568

322715

488

265

22

74

76

728

6307

7959

9A

Stonecutters Island

HATS

7474

230

7704

325

2793

2263

26

4

14

1

16

17

25

103

11

Tsuen Wan West (Rural Area)

 

32737

1661

34398

468

8974

6926

851

0

0

0

5

1

13

870

12

Tuen Mun

 

536117

17189

553306

98486

136797

99032

1041

558

30

32

599

736

8775

11770

13

Discovery Bay

 

16175

456

16631

1780

5186

4386

0

0

0

0

0

0

31

31

14

Peng Chau

 

2557

14

2571

203

581

287

0

0

0

0

0

0

4

4

15

Mui Wo

 

7952

220

8172

1032

3306

2588

0

0

0

0

0

2

17

19

16

Hei Ling Chau

 

5138

29

5167

409

1168

576

2

0

1

0

1

1

2

9

17

Cheung Chau

 

22300

257

22557

4823

5746

4052

24

3

0

2

0

8

58

97

18

Shek Pik

 

1837

13

1851

289

876

564

6

0

0

0

0

0

0

6

19

Lamma Island

 

6103

100

6203

342

2220

1978

11

0

0

1

13

0

0

25

20A

Pokfulam Sanday Bay

 

7825

383

8207

4290

6956

6407

10

0

0

1

2

1

18

32

20B

Cyber Port

 

15761

868

16630

1878

7528

5643

34

0

0

3

7

2

59

105

21

Wah Fu Estates and Mt. Kellet

 

38031

1268

39299

7419

7787

6544

0

0

0

0

19

0

43

63

22

Aberdeen , Shouson Hill and Repulse Bay, Sou th Bay

 

129911

4013

133924

28656

60942

39980

233

5

1

59

140

70

1287

1796

23

Ap Lei Chau

 

84247

1864

86111

8734

21245

17415

123

1

0

2

95

28

362

611

26

Chung Hom Kok

 

1554

53

1606

271

574

390

0

0

0

0

0

0

0

0

27

Stanley

 

14855

498

15353

2438

5298

3486

0

0

0

0

0

0

25

25

28

Tai Tam

 

4229

127

4356

1455

1748

1434

0

0

0

0

0

3

9

12

29

Shek O

 

15125

562

15687

3117

8072

4198

1087

0

0

0

0

0

0

1087

30

Chai Wan

HATS

154216

5140

159356

31358

70762

41010

459

94

23

406

217

384

4461

6044

31

Shau Kei Wan

HATS

179728

6269

185996

22568

62901

37867

60

3

1

54

48

159

950

1276

32

North Point

 

233959

10956

244915

50562

173931

96241

373

18

5

853

406

290

4921

6867

33

Wan Chai East

 

84965

4335

89300

27540

138427

76801

94

29

0

213

62

73

1147

1619

34

Wan Chai West

 

67265

3250

70515

17938

267181

97232

166

7

0

276

207

461

2101

3219

35

Western and Central, Green Island

HATS

222336

7276

229612

45832

225574

106510

817

20

16

171

272

111

3515

4921

37

Tolo Harbour

 

1002755

35492

1038247

193645

339785

227874

3071

86

11

142

547

1141

15544

20542

38

Sheung Shui and Fanling

 

313281

11151

324432

57200

75812

54913

576

58

13

38

305

378

2595

3962

39

North New Territories

 

16676

311

16987

793

5898

2858

19

2

4

3

49

60

182

319

40

Sha Tau Kok

 

10643

289

10932

1226

2367

1505

28

1

0

16

6

6

16

73

10A

Kwai Chung and Tsuen Wan East

HATS

551887

19583

571470

95116

350029

181287

762

1058

82

167

509

1517

18301

22396

10B

Tsing Yi

HATS

188052

6824

194876

28942

57411

36450

131

200

1

6

352

177

5129

5995

12A

Yuen Long and Tin Shui Wai and Deepbay Streams

 

489931

15440

505371

83169

108767

83627

1029

86

0

38

260

372

1689

3474

12D

Yuen Long New Town and Kam Tin

 

158532

5194

163726

17200

38824

28467

849

0

28

0

252

382

2471

3982

13A

North Lantau

 

149768

7005

156773

15795

57855

52766

0

0

0

0

0

0

1390

1390

13B

Chek Lap Kok

 

2

0

2

0

61031

37949

0

0

0

0

7948

0

0

7948

15A

South Lantau

 

3234

28

3262

495

1385

905

0

0

0

0

0

1

9

9

17A

Shek Kwu Chau

 

147

1

148

23

70

45

0

0

0

0

0

0

0

0

17B

Tai A Chau

 

148

1

149

23

70

45

0

0

0

0

0

0

0

0

18A

Tai O

 

3172

23

3195

499

1513

974

6

0

0

0

0

0

4

10

19A

Poi Toi Islands

 

119

0

119

0

22

12

0

0

0

0

0

0

0

0

19B

Tung Lung

 

1135

50

1184

129

264

226

1

0

0

0

0

0

0

1

1A

Sai Kung Country Park

 

39451

1238

40689

7290

15185

11639

80

0

0

0

0

4

186

271

1B

Pak Sha Wan

 

36657

1412

38069

6663

8171

6719

37

0

0

0

5

7

56

104

1C

Clear Water Bay

 

4098

179

4277

466

954

816

0

0

0

0

0

0

4

4

 

 


Table A5-2-11 Population and Employment for Year 2020

ID

Sewage Catchment Area

Residential Population

School

Total Employment Number

Total Employment in Commercial Activities

Manufacturing Industries

Land Usual Residents

Mobile Residents

Total

Full-Time School Places

Food

Textile

Leather

Paper

Manufacturing

Machinery

Others

Total

1

Sai Kung

 

5075

265

5340

1004

1772

1403

9

0

0

0

11

3

10

33

2

Tseung Kwan O

HATS

470990

14454

485444

65345

116543

88117

950

155

0

348

2022

248

9885

13608

4

Yau Tong, East Kowloon

HATS

835360

36303

871664

120231

434738

230496

400

436

31

175

147

924

8415

10528

5

North Kowloon, Central Kowloon, South Kowloon

HATS

642979

41968

684947

110716

456397

259497

1036

340

30

53

108

367

11028

12963

8

Northwest Kowloon

HATS

899327

56938

956265

200673

535203

342928

676

367

31

103

105

1008

8738

11028

9A

Stonecutters Island

HATS

8812

469

9281

334

2604

1999

27

4

15

1

17

19

27

109

11

Tsuen Wan West (Rural Area)

 

36464

2453

38917

481

8810

6696

929

0

0

0

6

1

14

950

12

Tuen Mun

 

576343

19543

595886

101285

143273

104255

1071

574

31

33

616

757

9026

12107

13

Discovery Bay

 

16255

487

16742

1831

5751

4915

0

0

0

0

0

0

32

32

14

Peng Chau

 

2589

16

2605

209

597

297

0

0

0

0

0

0

4

4

15

Mui Wo

 

8466

289

8756

1062

3628

2886

0

0

0

0

0

2

17

19

16

Hei Ling Chau

 

5203

32

5235

420

1199

598

2

0

1

0

1

1

2

9

17

Cheung Chau

 

22362

271

22634

4961

5830

4164

25

4

0

3

1

9

59

99

18

Shek Pik

 

1914

14

1928

297

1174

853

6

0

0

0

0

0

0

6

19

Lamma Island

 

6294

115

6409

352

2306

2057

11

0

0

1

14

0

0

26

20A

Pokfulam Sanday Bay

HATS

9211

622

9833

4410

7031

6390

25

0

0

2

5

2

44

78

20B

Cyber Port

HATS

16355

1208

17563

1929

8966

6339

109

2

1

8

23

8

190

340

21

Wah Fu Estates and Mt. Kellet

HATS

39266

2044

41310

7631

8176

6935

0

0

0

0

19

0

43

61

22

Aberdeen , Shouson Hill and Repulse Bay, South Bay

HATS

128593

6138

134731

29474

70070

42620

278

6

2

71

167

84

1536

2143

23

Ap Lei Chau

HATS

82661

3007

85668

8984

24576

17760

317

2

0

6

246

73

935

1579

26

Chung Hom Kok

 

1567

78

1645

279

574

376

0

0

0

0

0

0

4

4

27

Stanley

 

15017

750

15766

2507

5448

3454

0

0

0

39

0

0

2851

39

28

Tai Tam

 

4900

279

5180

1497

1924

1529

0

0

0

0

0

10

29

10

29

Shek O

 

15583

788

16371

3206

9134

4571

1150

0

0

0

0

0

0

1150

30

Chai Wan

HATS

155606

7524

163130

32241

80207

44834

1789

366

88

1580

845

1497

17375

6166

31

Shau Kei Wan

HATS

179441

8994

188435

23213

67993

39246

351

20

6

315

284

930

5562

1905

32

North Point

HATS

228050

15704

243754

51998

181235

101075

1292

62

19

2958

1409

1007

17062

6746

33

Wan Chai East

HATS

85640

8132

93772

28319

142531

78287

402

122

0

908

264

311

4878

2006

34

Wan Chai West

HATS

65575

7316

72891

18445

285340

104663

621

27

0

1034

775

1724

7863

4181

35

Western and Central, Green Island

HATS

234676

14075

248751

47110

237575

111541

3176

76

62

664

1058

430

13656

5465

37

Tolo Harbour

 

1039046

39123

1078169

199121

358937

238781

13364

376

47

619

2380

4963

67636

21749

38

Sheung Shui and Fanling

 

322312

12057

334370

58831

78182

56757

1717

173

40

112

909

1125

7732

4075

39

North New Territories

 

17692

352

18044

816

6011

2928

46

6

9

6

116

145

436

328

40

Sha Tau Kok

 

12487

351

12838

1261

2472

1621

37

1

0

21

8

7

21

75

10A

Kwai Chung and Tsuen Wan East

HATS

560736

27597

588333

97817

385769

199122

920

1276

99

201

614

1830

22080

27021

10B

Tsing Yi

HATS

187472

8700

196172

29755

75830

40660

277

422

2

13

742

373

10822

12650

12A

Yuen Long and Tin Shui Wai and Deepbay Streams

 

520670

17007

537678

85546

114439

87605

986

82

0

36

250

357

1618

3329

12D

Yuen Long New Town and Kam Tin

 

179571

6071

185642

17691

41067

30491

873

0

29

0

259

393

2542

4096

13A

North Lantau

 

205807

9928

215736

16244

77355

71157

0

0

0

0

0

0

1429

1429

13B

Chek Lap Kok

 

2

0

2

0

68785

41880

0

0

0

0

9233

0

0

9233

15A

South Lantau

 

3446

32

3478

509

1844

1350

0

0

0

0

0

1

9

10

17A

Shek Kwu Chau

 

154

1

155

24

94

68

0

0

0

0

0

0

0

0

17B

Tai A Chau

 

154

1

155

24

94

69

0

0

0

0

0

0

0

0

18A

Tai O

 

3304

25

3329

513

2028

1473

6

0

0

0

0

0

5

11

19A

Poi Toi Islands

 

170

0

170

0

22

15

0

0

0

0

0

0

0

0

19B

Tung Lung

 

1024

64

1088

133

238

202

0

0

0

0

0

0

0

1

1A

Sai Kung Country Park

 

37684

2180

39865

7486

15611

12153

92

0

0

0

0

5

213

310

1B

Pak Sha Wan

 

37573

1913

39486

6851

8330

6928

37

0

0

0

5

7

57

106

1C

Clear Water Bay

 

3698

231

3929

479

860

728

0

0

0

0

0

0

3

3

 

 


Table A5-2-12 Population and Employment for Ultimate Year

ID

Sewage Catchment Area

Residential Population

School

Total Employment Number

Total Employment in Commercial Activities

Manufacturing Industries

Land Usual Residents

Mobile Residents

Total

Full-Time School Places

Food

Textile

Leather

Paper

Manufacturing

Machinery

Others

Total

1

Sai Kung

 

4761

460

5222

1073

1843

1485

11

0

0

0

14

4

12

42

2

Tseung Kwan O

HATS

510457

19403

529860

69883

114123

84916

1212

197

0

444

2577

316

12601

17346

4

Yau Tong, East Kowloon

HATS

944379

61871

1006250

128580

516811

268791

1030

1123

80

450

378

2381

21677

27119

5

North Kowloon, Central Kowloon, South Kowloon

HATS

774260

93600

867860

118404

513205

299002

1495

491

43

76

155

529

15905

18695

8

Northwest Kowloon

HATS

973223

103889

1077112

214609

579674

374944

1226

665

55

187

191

1829

15847

20000

9A

Stonecutters Island

HATS

10816

977

11793

357

2290

1533

31

5

17

2

19

21

31

126

11

Tsuen Wan West (Rural Area)

 

47110

4292

51401

515

8159

5878

1125

0

0

0

7

1

17

1149

12

Tuen Mun

 

616366

20901

637267

108318

153223

111495

1145

613

33

35

659

809

9652

12947

13

Discovery Bay

 

17384

521

17904

1958

6150

5257

0

0

0

0

0

0

34

34

14

Peng Chau

 

2769

17

2786

224

638

318

0

0

0

0

0

0

5

5

15

Mui Wo

 

9054

309

9364

1135

3880

3086

0

0

0

0

0

2

18

20

16

Hei Ling Chau

 

5564

34

5599

450

1282

639

2

0

2

0

2

2

2

9

17

Cheung Chau

 

23915

290

24205

5306

6235

4453

27

4

0

3

1

9

63

106

18

Shek Pik

 

2047

15

2062

318

1256

912

7

0

0

0

0

0

0

7

19

Lamma Island

 

6732

123

6855

376

2466

2200

12

0

0

1

15

0

0

28

20A

Pokfulam Sanday Bay

HATS

13020

1199

14219

4716

6982

6109

62

1

0

5

13

4

108

193

20B

Cyber Port

HATS

19067

2010

21077

2063

12373

7885

296

4

2

22

63

21

519

928

21

Wah Fu Estates and Mt. Kellet

HATS

45563

3922

49485

8160

9211

7926

0

0

0

0

18

0

40

58

22

Aberdeen , Shouson Hill and Repulse Bay, South Bay

HATS

135476

11260

146736

31521

88152

46562

550

13

3

140

331

166

3039

4241

23

Ap Lei Chau

HATS

84597

5755

90353

9608

32779

18337

804

4

0

14

624

185

2368

3999

26

Chung Hom Kok

 

1678

140

1818

298

576

341

0

0

0

0

0

0

7

7

27

Stanley

 

16144

1351

17495

2681

5827

3379

0

0

0

74

0

0

5367

74

28

Tai Tam

 

6907

653

7560

1600

2367

1767

0

0

0

0

0

4

12

4

29

Shek O

 

16848

1296

18144

3429

11579

5364

1411

0

0

0

0

0

0

1411

30

Chai Wan

HATS

166645

13125

179769

34480

100704

52555

2404

492

119

2123

1136

2011

23343

8284

31

Shau Kei Wan

HATS

188415

15360

203775

24825

79852

41946

669

38

11

601

541

1774

10615

3635

32

North Point

HATS

229933

26908

256841

55609

188749

100719

1513

73

22

3465

1651

1179

19987

7902

33

Wan Chai East

HATS

87426

16992

104418

30286

150048

80303

564

171

0

1275

371

436

6851

2818

34

Wan Chai West

HATS

65080

17235

82315

19726

292850

108947

702

31

0

1169

876

1949

8888

4727

35

Western and Central, Green Island

HATS

256768

30007

286775

50381

260025

119376

3829

92

75

800

1275

519

16467

6590

37

Tolo Harbour

 

1111556

42945

1154501

212949

384014

255764

14283

402

50

662

2543

5305

72287

23245

38

Sheung Shui and Fanling

 

344695

12895

357590

62916

83612

60698

1836

185

42

120

972

1203

8269

4358

39

North New Territories

 

18921

376

19297

872

6428

3131

50

6

9

7

124

155

466

351

40

Sha Tau Kok

 

13354

375

13729

1349

2643

1733

40

1

0

22

9

8

22

80

10A

Kwai Chung and Tsuen Wan East

HATS

599274

45742

645016

104610

445796

231040

1434

1989

154

314

957

2852

34410

42110

10B

Tsing Yi

HATS

196193

12870

209063

31822

83197

45385

321

489

2

15

860

433

12547

14666

12A

Yuen Long and Tin Shui Wai and Deepbay Streams

 

556828

18188

575016

91486

122386

93688

1054

88

0

39

267

381

1730

3560

12D

Yuen Long New Town and Kam Tin

 

192041

6493

198534

18919

43918

32608

934

0

31

0

277

421

2719

4381

13A

North Lantau

 

220100

10618

230717

17373

82727

76098

0

0

0

0

0

0

1528

1528

13B

Chek Lap Kok

 

2

0

2

0

73562

44789

0

0

0

0

9874

0

0

9874

15A

South Lantau

 

3686

35

3720

544

1973

1443

0

0

0

0

0

1

9

10

17A

Shek Kwu Chau

 

164

1

165

25

101

73

0

0

0

0

0

0

0

1

17B

Tai A Chau

 

164

1

166

26

101

73

0

0

0

0

0

0

0

1

18A

Tai O

 

3534

26

3560

548

2168

1575

6

0

0

0

0

0

5

11

19A

Poi Toi Islands

 

181

0

181

0

23

16

0

0

0

0

0

0

0

0

19B

Tung Lung

 

708

92

800

142

158

126

0

0

0

0

0

0

0

0

1A

Sai Kung Country Park

 

32699

4354

37054

8006

16110

12819

121

0

0

0

0

6

280

407

1B

Pak Sha Wan

 

38827

2949

41776

7327

8485

7203

39

0

0

0

5

7

59

110

1C

Clear Water Bay

 

2558

333

2891

513

570

455

0

0

0

0

0

0

1

1


 

Unit Flow and Load Factors

 

4.11            Relevant per head flow and load were assigned to residential, transient, commercial and industrial population to obtain the quantity and quality of total untreated wastewater by individual catchment areas.  Table A5-2-13 to Table A5-2-17 shows the flow and load factors. 

 

Table A5-2-13 Domestic Flow and Load Factors for Resident Population

Description

Flow 1 (m3/d/head)

SS 2

BOD52

TKN 2

NH3-N 2

TP 3

Cu3

E. coli 2

 

(all in g/d/head except E.coli in no./d/head)

 

2009

2013 /2020 /ultimate

 

Usual residents

 

Sandy Bay

0.341

0.35

40

42

8.5

5.0

1.33

0.0065

4.3E+10

 

Stanley, Discovery Bay

0.29

0.29

40

42

8.5

5.0

1.33

0.0065

4.3E+10

 

Shek O

0.329

0.35

40

42

8.5

5.0

1.33

0.0065

4.3E+10

 

Outlying Island, Sai Kung

0.27

0.27

40

42

8.5

5.0

1.33

0.0065

4.3E+10

 

Yuen Long, Mui Wo

0.244

0.25

40

42

8.5

5.0

1.33

0.0065

4.3E+10

 

Aberdeen, Wan Chai, North Lantau

0.23

0.23

40

42

8.5

5.0

1.33

0.0065

4.3E+10

 

Sha Tin, Tai Po

0.22

0.22

40

42

8.5

5.0

1.33

0.0065

4.3E+10

 

San Wai

0.221

0.23

40

42

8.5

5.0

1.33

0.0065

4.3E+10

 

Wah Fu, Shek Wu Hui, N

0.207

0.21

40

42

8.5

5.0

1.33

0.0065

4.3E+10

 

Northwest Kowloon, Tuen Mun, Central, North Point

0.2

0.2

40

42

8.5

5.0

1.33

0.0065

4.3E+10

 

Ap Lei Chau, Chai Wan, Shau Kei Wan, Central Kowloon, East Kowloon, Kwai Chung, Tsing Yi, Tseung Kwan O

0.19

0.19

40

42

8.5

5.0

1.33

0.0065

4.3E+10

 

Mobile residents

0.19

40

42

8.5

5.0

1.33

0.0065

4.3E+10

 

Source of reference:

1.        Guidelines for Estimating Sewage Flows for Sewage Infrastructure Planning (Version 1.0), EPD, March 2005

2.        DSD Sewerage Manual

3.       EPD Update Study

 

Table A5-2-14 Domestic Flow and Load Factors for Transient Population

Description        

Flow 1 (m3/d/head)

SS 2

BOD52

TKN 2

NH3-N 2

TP 3

Cu3

E. coli 2

(all in g/d/head except E.coli in no./d/head)

Employed population

0.08

34

34

6.7

4.0

1.06

0.0052

3.5E+10

Students

0.04

34

34

6.7

4.0

1.06

0.0052

3.5E+10

Source of reference:

1.        Guidelines for Estimating Sewage Flows for Sewage Infrastructure Planning (Version 1.0), EPD, March 2005

2.        DSD Sewerage Manual

3.        EPD Update Study

 

Table A5-2-15 Flow and Load Factors for Commercial Activities

Description

Flow 1 (m3/d/employee)

SS 2

BOD52

TKN 2

NH3-N 2

TP 3

E.coli 2

(all in g/d/head except E.coli in no./d/head)

J2 Electricity Gas & Water

0.25

25

53

2.5

0.8

0.53

0

J3 Transport, Storage & Communication

0.1

25

53

2.5

0.8

0.53

0

J4 Wholesale & Retail

0.2

25

53

2.5

0.8

0.53

0

J9 Construction

0.15

25

53

2.5

0.8

0.53

0

J10 Restaurants & Hotels

1.5

25

53

2.5

0.8

0.53

0

J11 Community, Social & Personal Services

0.2

25

53

2.5

0.8

0.53

0

Source of reference:

1.        Guidelines for Estimating Sewage Flows for Sewage Infrastructure Planning (Version 1.0), EPD, March 2005

2.        DSD Sewerage Manual

3.        EPD Update Study

 

Table A5-2-16 Flow Factors for Industrial Activities

Catchment

Flow 1 (m3/d/employee)

J1 Manufacturing

Hong Kong Island (except Aberdeen & Ap Lei Chau), San Po Kong

0.25

North West Kowloon

0.45

East Kowloon, Sha Tin, Lantau Island (except Mui Wo)

0.45

Central Kowloon, North District, Aberdeen, Ap Lei Chau

0.55

Tsuen Wan, Kwai Chung

0.65

Tai Po

0.75

Tuen Mun, Tseung Kwan O, Yau Tong, Cheung Chau, Mui Wo

1

Tsing Yi

1.5

Sai Kung, Yuen Long

2

Source of reference:

1.        Guidelines for Estimating Sewage Flows for Sewage Infrastructure Planning (Version 1.0), EPD, March 2005

 

Table A5-2-17 Load Factors for Industrial Activities

Category

SS 1

BOD5 1

TKN 1

NH3-N 1

Cu 1

E.coli 1

(all in g/d/employee except E.coli in no./d/employee)

J1 Manufacturing

Food

502

713

39

0

0

0

Textiles

2095

3680

67

0

4.4

0

Leather

115

115

29

7

0.1

0

Paper

2228

2150

33

0

0

0

Manufacturing

355

931

0

0

2.4

0

Machinery

40

90

29

22

0.9

0

Source of reference:

1.        EPD Update Study

 

4.12            Pollution load generation factors for OrthoP and silica are not available. The following assumptions were adopted for calculating OrthoP and silica loading in raw sewage.

 

l          TP to OrthoP is 1.68 based on the actual measurements of raw sewage at Sha Tin STW and Yuen Long STW.

l          The silica content is approximately 9 mg/l based on the actual measurements of raw sewage at Sha Tin STW.

 

5                     Concurrent Discharges from HATS and other Major STW

 

5.1               Effluent discharges from the key STW within the modelling areas were considered separately.  These key discharges include the effluent flow from SCISTW, PPSTW, SHWSTW, NWNT outfall, SHTSTW and THEES.  The assumed effluent concentrations assumed for these discharges are tabulated in Appendix 5-4 which are based on the information from recent studies and actual measurements.  The methodology for compiling the flow rates of these key STW is given below.

 

Flow Estimation for 2009, 2012 and 2020

 

5.2               For the purpose of water quality modelling, it was proposed to use the average flow calculated using the unit flow factors from the GESF [1] and the methodologies discussed in Section 3 and Section 4 for the discharge from SCISTW, PPSTW, SHWSTW, NWNT outfall, SHTSTW and THEES.  The average flow used for these STW discharges had also taken into account the catchment inflow factors (PCIF) from the GESF as shown in Table A5-2-18 below.  Flow from relevant landfills and beach facilities as shown in Table A5-2-4 and Table A5-2-5 was also included in the flow estimation wherever applicable.

 

Table A5-2-18 Catchment Inflow Factors from the GESF

Catchment

Catchment Inflow Factor

Central, North Point, Sandy Bay, Wan Chai, Wah Fu, Central Kowloon, Stanley, Yuen Long, San Wai, North District, Tai Po, North Lantau, Mui Wo

1.00

Chai Wan, Kwai Chung, Tsing Yi, East Kowloon , Tuen Mun

1.10

Sha Tin

1.15

Tseung Kwan O

1.20

Shau Kei Wan

1.25

Aberdeen, Ap Lei Chau, Northwest Kowloon, Sai Kung

1.30

Cheung Chau, Shek O

1.50

 

5.3               It was assumed that the sewage flow discharged from the catchments of HATS, PPSTW, SHWSTW, NWNT outfall, SHTSTW and THEES was 105% of the total estimated flow that would be generated in the catchment for conservative assessment.  For example, as shown in Table A5-2-1, 10% of the total sewage flow generated in the Chai Wan catchment would be lost to the storm.  For the purpose of modelling, 95% of the total flow generated in the Chai Wan catchment was assumed for discharge to the SCISTW for treatment (i.e. 105% of the total flow was used).  For regions outside the catchments of SCISTW, SHWSTW, PPSTW, NWNT outfall, SHTSTW and THEES, it was assumed that the total flow would remain 100%.

 

5.4               Table A5-2-19 gives the effluent flow for SCISTW calculated for 2009, 2013 and 2020 using the methodology described above. 

 

Table A5-2-19 Estimated Effluent Flow for SCISTW 

Year

Flow Rate (m3/day) With PCIF

2009

1576300

2013

1661100

2020

2341600

 

Flow Estimation for Ultimate Scenario

 

5.5               It was proposed to use the design plant capacity to calculate the loading discharged from the major STW for ultimate year as shown below:

 

l          PPSTW – 558,000 m3/day

l          SHWSTW – 168,937 m3/day

l          YLSTW – 70,000 m3/day

l          SWSTW – 246,000 m3/day

l          THEES – 470,000 m3/day

l          SCISTW – 2,800,000 m3/day

l          SHTSTW – 16,848 m3/day

 

6                     Point Source Pollution Loads

 

6.1               The pollution loads from typhoon shelters, marine culture zones adopted in the EEFS are summarized in Table A5-2-20 and Table A5-2-21.  These pollution loads were included in the water quality model under 2009, 2013, 2020 and ultimate scenarios for cumulative assessment.  Loading from landfills and beaches that would not be connected to the STW is summarized in Table A5-2-22 and Table A5-2-23.

                                                                                                                                

Table A5-2-20       Pollution Flows and Loads from Typhoon Shelter

Typhoon shelters

Flow (m3/d)

BOD (g/d)

SS

(g/d)

Org-N (g/d)

NH3-N (g/d)

E.coli (no./d)

Copper (g/d)

TP

(g/d)

OrthoP (g/d)

Silicate (g/d)

Shau Kei Wan

149

41670

39686

3473

4961

4.27E+14

6

1320

785

1279

Sam Ka Tsuen

39

10803

10289

900

1286

1.11E+13

2

342

204

332

Kwun Tong

22

6055

5766

505

721

6.20E+12

1

192

114

186

Causeway Bay

179

50099

47714

4175

5964

5.13E+13

8

1586

944

1538

Yau Ma Tei

184

51643

49183

4304

6148

5.29E+13

8

1635

973

1586

Rambler Channel

36

10032

9554

836

1194

1.03E+13

2

318

189

308

Aberdeen

388

108746

103568

9062

12946

1.11E+14

17

3444

2050

3339

Tuen Mun

138

38643

36803

3220

4600

3.96E+13

6

1224

728

1186

Cheung Chau

166

46597

44378

3883

5547

4.77E+13

7

1476

878

1431

Shuen Wan (Yim Tin Tsai)

49

13712

13059

1143

1632

1.40E+13

2

434

258

421

Sai Kung

81

22794

21709

1899

2714

2.33E+13

4

722

430

700

Chai Wan

44

12347

11759

1029

1470

1.26E+13

2

391

233

379

To Kwa Wan

53

14840

14133

1237

1767

1.52E+13

2

470

280

456

 

Table A5-2-21       Pollution Flows and Loads from Marine Culture Zone

Marine Culture Zone

BOD (g/d)

SS (g/d)

Org-N (g/d)

NH3-N (g/d)

TP (g/d)

OrthoP (g/d)

Sha Tau Kok

42806

124916

10569

38075

2038

1595

Ap Chau

999

2915

247

888

48

37

Kat O

7705

22485

1902

6854

367

287

O Pui Tong

25113

73284

6200

22338

1196

936

Sai Lau Kong

1712

4997

423

1523

82

64

Wong Wan

5351

15615

1321

4759

255

199

Tap Mun

17217

50244

4251

15315

820

642

Kau Lau Wan

2663

7773

658

2369

127

99

Sham Wan

42948

125333

10604

38202

2045

1600

Lo Fu Wat

1284

3747

317

1142

61

48

Yung Shue Au

81330

237341

20081

72343

3872

3031

Leung Shuen Wan

4114

12006

1016

3659

196

153

Tiu Cham Wan

4043

11798

998

3596

192

151

Tai Tau Chau

14934

43582

3687

13284

711

557

Kai Lung Wan

6432

18769

1588

5721

306

240

Kau Sai

10987

32062

2713

9773

523

409

Ma Nam Wat

9536

27829

2355

8482

454

355

Po Toi O

9084

26510

2243

8080

432

339

Po Toi

33579

97990

8291

29868

1599

1251

Sok Kwu Wan

25969

75783

6412

23099

1236

968

Lo Tik Wan

11011

32131

2719

9794

524

410

Ma Wan

50939

148650

12577

45310

2425

1898

Yim Tin Tsai

35552

103750

8778

31624

1693

1325

Cheung Sha Wan

19025

55518

4697

16922

906

709

Yim Tin Tsai (East)

35499

103750

4406

31754

1197

1051

Tung Lung Chau

18996

55518

2358

16992

640

562

 

Table A5-2-22 Pollution Flows and Loads from Landfills

Landfill

Flow (m3/d)

BOD

(kg/d)

SS

(kg/d)

Org-N (kg/d)

NH3-N

(kg/d)

E-Coli (no./d)

Cu

(g/d)

Shuen Wan Landfill Leachate seepage into coastal waters

50

10

10

10

90

3.48E+05

1

 

Table A5-2-23 Pollution Flows and Loads from Beaches

Gazetted Beach

Flow

(m3/d)

BOD

(g/d)

SS

(g/d)

Org-N

(g/d)

NH3-N

(g/d)

E.coli.

(no./d)

TP

(g/d)

OrthoP

(g/d)

Cheung Sha Lower

1

245

204

135

307

3.24E+12

70

42

Cheung Sha Upper

0

95

79

52

118

1.25E+12

27

16

Pui O

1

152

126

83

190

2.00E+12

43

26

Tong Fuk

1

188

156

103

234

2.48E+12

53

32

Hap Mun Bay

13

3204

2670

1757

4004

4.23E+13

912

543

Kiu Tsui

1

353

294

194

441

4.66E+12

100

60

Tung Wan, Ma Wan

2

485

404

266

607

6.40E+12

138

82

Clear Water Bay 1st

5

1340

1117

735

1675

1.77E+13

381

227

Clear Water Bay 2nd

46

11385

9487

6246

14231

1.50E+14

3240

1928

 

 

7                     Contributions of Pollution Loads from Major Sources

 

7.1               The contributions of pollution loads from major sources for selected parameters are provided in Table A5-2-24, Table A5-2-25, Table A5-2-26 and Table A5-2-27 for 2009, 2013, 2020 and ultimate scenarios respectively.  The loads contributed from treated sewage effluent for the non-HATS catchments would reduce in 2013 as compared to those in 2009 due to the assumption that the treatment level of PPSTW would be upgraded in 2013.  After collection of the sewage from PTWs in the western and southern Hong Kong Island under HATS Stage 2A, the pollution loads contributed from the HATS treated effluent would significantly increase in 2020.  However, the contribution from HATS would significantly reduce under the ultimate scenario as it was assumed that the treatment level of SCISTW would be upgraded under HATS Stage 2B.  The tables also showed that the contributions from landfills, beaches, marine culture zones, livestock wastes and typhoon shelters were all very small.


Table A5-2-24   Contributions from Major Pollution Sources for 2009

 Pollution Sources

BOD

SS

Org-N

NH3-N

E.coli

g/d

% contribution

g/d

% contribution

g/d

% contribution

g/d

% contribution

no./day

% contribution

Storm outfalls – dry weather load - rainfall related load not included – HATS catchments

40304785

8.37%

34555698

6.81%

2766746

5.19%

3696147

5.74%

3.09E+16

9.25%

Storm outfalls – dry weather load - rainfall related load not included – non HATS catchments

24506057

5.09%

21421356

4.22%

1773022

3.33%

2385558

3.70%

2.01E+16

6.01%

HATS outfall – Stage 1 (after treatment)

107188400

22.26%

66204600

13.04%

15652659

29.39%

27474909

42.66%

1.58E+17

47.22%

Other sewage outfalls (after treatment) - Non HATS sewage effluent

198257082

41.18%

181373773

35.73%

26513235

49.78%

24181419

37.54%

1.20E+17

35.86%

Rainfall related loading (for wet season) in HATS catchments

28360688

5.89%

54564046

10.75%

1513916

2.84%

252319

0.39%

0

0.00%

Rainfall related loading (for wet season) in non HATS catchments

75067062

15.59%

144423952

28.45%

4007139

7.52%

667856

1.04%

0

0.00%

Landfills

6746000

1.40%

1574000

0.31%

758000

1.42%

5062000

7.86%

4.26E+07

0.00%

Beaches

70587

0.01%

58821

0.01%

38725

0.07%

88229

0.14%

9.31E+14

0.28%

Marine culture zones

518828

0.11%

1514296

0.30%

121411

0.23%

461766

0.72%

0

0.00%

Livestock wastes

0

0.00%

1491000

0.29%

80000

0.15%

90000

0.14%

3.81E+15

1.14%

Typhoon shelters

427981

0.09%

407601

0.08%

35666

0.07%

50950

0.08%

8.22E+14

0.25%

Total

481447471

100.00%

507589144

100.00%

53260519

100.00%

64411155

100.00%

3.34E+17

100.00%

 

Table A5-2-25   Contributions from Major Pollution Sources for 2013

 Pollution Sources

BOD

SS

Org-N

NH3-N

E.coli

g/d

% contribution

g/d

% contribution

g/d

% contribution

g/d

% contribution

no./day

% contribution

Storm outfalls – dry weather load - rainfall related load not included – HATS catchments

41888350

8.98%

35906851

7.60%

2883907

5.62%

3857647

5.86%

3.22E+16

10.87%

Storm outfalls – dry weather load - rainfall related load not included – non HATS catchments

24586906

5.27%

21460865

4.54%

1776178

3.46%

2388607

3.63%

2.01E+16

6.77%

HATS outfall – Stage 1 (after treatment)

112954800

24.22%

69766200

14.77%

16494723

32.13%

28952973

43.95%

1.66E+17

56.03%

Other sewage outfalls (after treatment) - Non HATS sewage effluent

175733277

37.68%

141180446

29.89%

23629288

46.03%

23998075

36.43%

7.25E+16

24.45%

Rainfall related loading (for wet season) in HATS catchments

28360688

6.08%

54564046

11.55%

1513916

2.95%

252319

0.38%

0

0.00%

Rainfall related loading (for wet season) in non HATS catchments

75067062

16.10%

144423952

30.58%

4007139

7.81%

667856

1.01%

0

0.00%

Landfills

6746000

1.45%

1574000

0.33%

758000

1.48%

5062000

7.68%

4.26E+07

0.00%

Beaches

70587

0.02%

58821

0.01%

38725

0.08%

88229

0.13%

9.31E+14

0.31%

Marine culture zones

518828

0.11%

1514296

0.32%

121411

0.24%

461766

0.70%

0.00E+00

0.00%

Livestock wastes

0

0.00%

1491000

0.32%

80000

0.16%

90000

0.14%

3.81E+15

1.29%

Typhoon shelters

427981

0.09%

407601

0.09%

35666

0.07%

50950

0.08%

8.22E+14

0.28%

Total

466354480

100.00%

472348079

100.00%

51338953

100.00%

65870422

100.00%

2.96E+17

100.00%

 

 

Table A5-2-26   Contributions from Major Pollution Sources for 2020

Pollution Sources

BOD

SS

Org-N

NH3-N

E.coli

g/d

% contribution

g/d

%

contribution

g/d

% contribution

g/d

% contribution

no./day

% contribution

Storm outfalls – dry weather load - rainfall related load not included – HATS catchments

47353303

10.79%

40415034

9.28%

3145086

5.89%

4146103

5.75%

3.45E+16

11.58%

Storm outfalls – dry weather load - rainfall related load not included – non HATS catchments

27552496

6.28%

23715389

5.44%

1939831

3.63%

2547807

3.54%

2.13E+16

7.15%

HATS outfall – Stage 2A (after treatment)

159228800

36.30%

98347200

22.58%

23252088

43.51%

40814088

56.63%

2.34E+17

78.51%

Other sewage outfalls (after treatment) - Non HATS sewage effluent

93369656

21.28%

69036457

15.85%

18548691

34.71%

17885197

24.82%

2.68E+15

0.90%

Rainfall related loading (for wet season) in HATS catchments

28360688

6.46%

54564046

12.53%

1513916

2.83%

252319

0.35%

0.00E+00

0.00%

Rainfall related loading (for wet season) in non HATS catchments

75067062

17.11%

144423952

33.16%

4007139

7.50%

667856

0.93%

0.00E+00

0.00%

Landfills

6746000

1.54%

1574000

0.36%

758000

1.42%

5062000

7.02%

4.26E+07

0.00%

Beaches

70587

0.02%

58821

0.01%

38725

0.07%

88229

0.12%

9.31E+14

0.31%

Marine culture zones

518828

0.12%

1514296

0.35%

121411

0.23%

461766

0.64%

0.00E+00

0.00%

Livestock wastes

0

0.00%

1491000

0.34%

80000

0.15%

90000

0.12%

3.81E+15

1.28%

Typhoon shelters

427981

0.10%

407601

0.09%

35666

0.07%

50950

0.07%

8.22E+14

0.28%

Total

438695402

100.00%

435547796

100.00%

53440552

100.00%

72066315

100.00%

2.98E+17

100.00%

 

Table A5-2-27   Contributions from Major Pollution Sources for Ultimate Scenario

 Pollution Sources

BOD

SS

Org-N

NH3-N

E.coli

g/d

% contribution

g/d

% contribution

g/d

% contribution

g/d

% contribution

no./day

% contribution

Storm outfalls – dry weather load - rainfall related load not included – HATS catchments

54573743

12.26%

46377408

10.32%

3569775

7.29%

4673577

9.12%

3.89E+16

48.86%

Storm outfalls – dry weather load - rainfall related load not included – non HATS catchments

29317389

6.59%

25227973

5.61%

2062550

4.21%

2706001

5.28%

2.26E+16

28.47%

HATS outfall – Stage 2B (after treatment)

67200000

15.09%

44800000

9.97%

7000000

14.30%

5600000

10.92%

8.28E+15

10.41%

Other sewage outfalls (after treatment) - Non HATS sewage effluent

182903664

41.08%

128931535

28.69%

29779379

60.82%

31606789

61.66%

4.20E+15

5.28%

Rainfall related loading (for wet season) in HATS catchments

28360688

6.37%

54564046

12.14%

1513916

3.09%

252319

0.49%

0.00E+00

0.00%

Rainfall related loading (for wet season) in non HATS catchments

75067062

16.86%

144423952

32.14%

4007139

8.18%

667856

1.30%

0.00E+00

0.00%

Landfills

6746000

1.52%

1574000

0.35%

758000

1.55%

5062000

9.88%

4.26E+07

0.00%

Beaches

70587

0.02%

58821

0.01%

38725

0.08%

88229

0.17%

9.31E+14

1.17%

Marine culture zones

518828

0.12%

1514296

0.34%

121411

0.25%

461766

0.90%

0.00E+00

0.00%

Livestock wastes

0

0.00%

1491000

0.33%

80000

0.16%

90000

0.18%

3.81E+15

4.79%

Typhoon shelters

427981

0.10%

407601

0.09%

35666

0.07%

50950

0.10%

8.22E+14

1.03%

Total

445185943

100.00%

449370633

100.00%

48966560

100.00%

51259488

100.00%

3.89E+16

48.86%

 

 



[1] Guidelines for Estimating Sewage Flows for Sewage Infrastructure Planning (Version 1.0), EPD, March 2005