Tolo Harbour and Channel Water Control Zone Statement of Water Quality Objectives for Watercourses
[24 June 1988]
(Format changes—E.R. 5 of 2019)
The water quality objectives set out in the first column of Schedule 1 have been established for watercourses in the subzones defined in Schedule 2 and delineated in Schedule 3 described opposite such water quality objectives in the second column of Schedule 1.
| A. | AESTHETIC APPEARANCE | ||||
| Waste discharges shall not cause waters of the subzone to contain substances that— | All watercourses | ||||
| (a)settle to form objectionable deposits; (b)float as debris, scum, oil or other matter to form nuisances; (c)produce objectionable colour, odour, taste or turbidity; (d)injure or are toxic or produce adverse physiological responses in humans, animals or plants; or (e)are conducive to undesirable aquatic life or a nuisance to aquatic life. | |||||
| B. | BACTERIA | ||||
| Waste discharges shall not cause the level of Escherichia coli to exceed 1 000 per 100 mL in waters of the subzone, levels to be calculated as a running median of the most recent 5 consecutive samples taken at intervals of between 7 and 21 days (or 14 and 42 days). | (a)SM(A) (b)SM(C) (c)SM(D) (d)SM(E) (e)SM(H) (f)SM(I) (g)TP(B) (h)TP(C) (i)other watercourses | ||||
| Waste discharges shall not cause the level of Escherichia coli to exceed 0 per 100 mL in waters of the subzone, levels to be calculated as a running median of the most recent 5 consecutive samples taken at intervals of between 7 and 21 days (or 14 and 42 days). | (a)SM(B) (b)SM(F) (c)SM(G) (d)LT(C) (e)LT(D) (f)TP(A) | ||||
| C. | COLOUR | ||||
| Waste discharges shall not cause the colour of waters of the subzone to exceed 50 Hazen units at any time. | (a)SM(A) (b)SM(C) (c)SM(D) (d)SM(E) (e)SM(H) (f)SM(I) (g)TP(B) (h)TP(C) (i)other watercourses | ||||
| Waste discharges shall not cause the colour of waters of the subzone to exceed 30 Hazen units at any time. | (a)SM(B) (b)SM(F) (c)SM(G) (d)LT(C) (e)LT(D) (f)TP(A) | ||||
| D. | pH | ||||
| Waste discharges shall not cause the pH of waters of the subzone to exceed the range of 6.0 to 9.0 at any time. | (a)SM(D) (b)SM(E) (c)SM(I) (d)other watercourses | ||||
| Waste discharges shall not cause the pH of waters of the subzone to exceed the range of 6.5 to 8.5 at any time. | (a)SM(A) (b)SM(B) (c)SM(C) (d)SM(F) (e)SM(G) (f)SM(H) (g)LT(C) (h)LT(D) (i)TP(A) (j)TP(B) (k)TP(C) | ||||
| E. | TEMPERATURE | ||||
| Waste discharges shall not cause the natural daily temperature range in waters of the subzone to be extended by greater than ± 2.0 degrees Celsius at any location or time. | All watercourses | ||||
| F. | SUSPENDED SOLIDS | ||||
| Waste discharges shall not cause the annual median of suspended solids in waters of the subzone to exceed 25 milligrams per litre. | (a)SM(D) (b)SM(E) (c)SM(I) (d)other watercourses | ||||
| Waste discharges shall not cause the annual median of suspended solids in waters of the subzone to exceed 20 milligrams per litre. | (a)SM(A) (b)SM(B) (c)SM(C) (d)SM(F) (e)SM(G) (f)SM(H) (g)LT(C) (h)LT(D) (i)TP(A) (j)TP(B) (k)TP(C) | ||||
| G. | DISSOLVED OXYGEN | ||||
| Waste discharges shall not cause the level of dissolved oxygen in waters of the subzone to be less than 4 milligrams per litre or 40% saturation (at 15 degrees Celsius) at any time. | All watercourses | ||||
| H. | 5 DAYS BIOCHEMICAL OXYGEN DEMAND | ||||
| Waste discharges shall not cause the 5 days biochemical oxygen demand in waters of the subzone to exceed 5 milligrams per litre at any time. | (a)SM(A) (b)SM(C) (c)SM(D) (d)SM(E) (e)SM(H) (f)SM(I) (g)TP(B) (h)TP(C) (i)other watercourses | ||||
| Waste discharges shall not cause the 5 days biochemical oxygen demand in waters of the subzone to exceed 3 milligrams per litre at any time. | (a)SM(B) (b)SM(F) (c)SM(G) (d)LT(C) (e)LT(D) (f)TP(A) | ||||
| I. | CHEMICAL OXYGEN DEMAND | ||||
| Waste discharges shall not cause the chemical oxygen demand in waters of the subzone to exceed 30 milligrams per litre at any time. | (a)SM(A) (b)SM(C) (c)SM(D) (d)SM(E) (e)SM(H) (f)SM(I) (g)TP(B) (h)TP(C) (i)other watercourses | ||||
| Waste discharges shall not cause the chemical oxygen demand in waters of the subzone to exceed 15 milligrams per litre at any time. | (a)SM(B) (b)SM(F) (c)SM(G) (d)LT(C) (e)LT(D) (f)TP(A) | ||||
| J. | AMMONIACAL NITROGEN | ||||
| Waste discharges shall not cause the ammoniacal nitrogen in waters of the subzone to exceed 0.5 milligrams per litre at any time. | All watercourses | ||||
| K. | TOXICANTS | ||||
| Waste discharges shall not cause the toxicants in waters of the subzone to attain such a level as to produce significant toxic effects in humans, fish or any other aquatic organism, with due regard to biologically cumulative effects in food chains and to toxicant inter-actions with each other. | All watercourses | ||||
A watercourse is defined as a system that carries natural drainage storm water, excluding foul sewage systems. Wholly enclosed nullahs will not be included except when the condition of the water in the nullah poses a potential health risk to human beings or the environment by draining into a watercourse.
In the statement of water quality objectives for the watercourses in the Tolo Harbour and Channel Water Control Zone, the subzones are defined as follows—
| Shing Mun River | : | SM(A), SM(B), SM(C), SM(D), SM(E), SM(F), SM(G), SM(H), SM(I). |
| Lam Tsuen River | : | LT(C), LT(D). |
| Tai Po River | : | TP(A), TP(B), TP(C). |
| Other watercourses | : | All other watercourses except those within the above defined subzones. |
| The delineation of subzones for water quality objectives for watercourses in the Tolo Harbour and Channel Water Control Zone is under section 5(5) of the Water Pollution Control Ordinance (Cap. 358). Within Shing Mun River catchment, below the water gathering ground, there are 9 subzones, namely SM(A) to SM(I). In Tai Po area, there are 3 subzones for the Tai Po River, namely TP(A) to TP(C), and 2 subzones for the Lam Tsuen River, namely LT(C) and LT(D). |
| Shing Mun River Subzones |
| SM(A) subzone—All that area bounded by the Kowloon-Canton Railway in the south-east, by the water catchment boundary in the north-west, and by a line between south of Yau Oi Tsuen (22º23'16"N, 114º10'33"E) and the northern tip of the bridge at Tai Wai (22º22'36"N, 114º10'43"E). |
| This subzone includes the following areas: Heung Fan Liu, Kuk Liu, Pak Tin, Tai Wai and Sha Tin Heights. |
| SM(B) subzone—All that area bounded by the western bank of the Shing Mun River Channel from the northern tip of the bridge at Tai Wai (22º22'36"N, 114º10'43"E) to the mid-section point (22º23'30"N, 114º11'50"E) of the western bank, and by the water catchment boundary in the north-west. |
| This subzone includes the following areas: To Fung Shan, Pai Tau Hang, Sheung Wo Che, Ha Wo Che, Pai Tau, Tung Lo Wan, Lek Yuen Estate and Wo Che Estate. |
| SM(C) subzone—All that area bounded by the western bank of the Shing Mun River Channel from the mid-section point (22º23'30"N, 114º11'50"E) to the section point (22º23'40"N, 114º11'58"E) of the western bank, and by the water catchment boundary in the north-west. |
| This subzone includes the following areas: Man Hang, Wo Liu Hang and Fo Tan. |
| SM(D) subzone—All that area bounded by the western bank of the Shing Mun River Channel from the section point (22º23'40"N, 114º11'58"E) to point (22º24'18"N, 114º12'37"E) near the channel mouth, and Lok Lo Ha (22º24'12"N, 114º11'49"E) in the north-west. |
| This subzone includes the following areas: Sha Tin Race Course, Jubilee Sports Centre* and Lok Lo Ha. |
| SM(E) subzone—All that area bounded by the eastern bank of the Shing Mun River Channel from the section point (22º23'57"N, 114º12'26"E) to the channel mouth (22º24'30"N, 114º13'00"E), and by the water catchment boundary in the south-east. |
| This subzone includes the following areas: A Kung Kok and part of Nui Po Shan (Turret Hill). |
| SM(F) subzone—All that area bounded by the eastern bank of the Shing Mun River Channel from the mid-section point (22º23'23"N, 114º11'54"E) to the point (22º23'57"N, 114º12'26"E) near the channel mouth, and by the water catchment boundary in the south-east. |
| This subzone includes the following areas: Shek Mun, Tai Shek Kwu, Nam Shan, Tai Lam Liu, Shek Kwu Lung, Fa Sam Hang, Tai Che, Wong Nai Tau, Shiu Lek Yuen and Ngau Pei Sha. |
| SM(G) subzone—All that area bounded by the eastern bank of the Shing Mun River Channel from the section point (22º22'32"N, 114º10'45"E) near Che Kung Miu to the mid-section point (22º23'23"N, 114º11'54"E) of the eastern bank, and by the water catchment boundary in the south-east. |
| This subzone includes the following areas: Yuen Chau Kok, Sha Tin Wai, Fui Yiu Ha, Tsok Pok Hang, Tsang Tai Uk, Sha Tin Tau, Lei Uk Tsuen, Che Kung Miu, San Tin Wai, Kak Tin and Hung Mui Kuk. |
| SM(H) subzone—All that area bounded by the Kowloon-Canton Railway in the north-west, by the water catchment boundary in the south-east, and by a line between the section point (22º22'32"N, 114º10'45"E) of the eastern bank of the Shing Mun River Channel and point (22º21'50"N, 114º10'50"E) south of Hung Mui Kuk. |
| This subzone includes the following areas: Tin Sam, Pak Shek, Sheung Keng Hau, Ha Keng Hau, Hin Tin, Tei Lung Hau and the Sha Tin Water Treatment Works. |
| SM(I) subzone—All that water in the Shing Mun River Channel bounded by the northern tip (22º22'36"N, 114º10'43"E) and the southern tip (22º22'34"N, 114º10'42"E) of the bridge at Tai Wai and by the channel mouth (22º24'34"N, 114º12'53"E; 22º24'30"N, 114º13'00"E). |
| This subzone includes the water of the main Shing Mun River Channel. |
| Tai Po River Subzones |
| TP(A) subzone—All that area bounded by the water catchment boundary in the south-west and by a line between the point (22º25'55"N, 114º9'20"E) north of Yuen Tun Ha to point (22º25'36"N, 114º10'00"E) east of Lo Lau Uk. |
| This subzone includes the following area: Lo Lau Uk. |
| TP(B) subzone—All that area bounded by a line between the point (22º26'17"N, 114º10'10"E) south of Sheung Wong Yi Au and point (22º26'36"N, 114º8'56"E) south-west of Pun Chun Yuen, and by the water catchment boundary in the north-west and south-east. |
| This subzone includes the following areas: Pun Shan Chau, San Uk Ha, and Sheung Wun Yiu, Ha Wun Yiu and Lai Chi Shan. |
| TP(C) subzone—All that area bounded by the southern bank of the Kowloon-Canton Railway from the point (22º26'44"N, 114º10'21"E) north of Ha Wong Yi Au to the Railway Museum (22º26'58"N, 114º9'40"E), and by a line between south of Sheung Wong Yi Au (22º26'17"N, 114º10'10"E) and south-east of Pun Chun Yuen (22º26'48"N , 114º9'20"E). |
| This subzone includes the following areas: Pan Chung, Wan Tau Tong, Pak Kiu Tsai, To Yuen Tung, Ma Wo and Yiu Tsz Kin. |
| Lam Tsuen River Subzones |
| LT(C) subzone—All that area bounded by the southern bank of the Kowloon-Canton Railway from Shui Wai (22º27'15"N, 114º9'24"E) to Mui Shue Hang (22º27'32"N, 114º8'56"E), and by the water catchment boundary in the west. |
| This subzone includes the following areas: Shui Wai and Mui Shue Hang. |
| LT(D) subzone—All that area bounded by the southern bank of the Kowloon-Canton Railway from the Railway Museum (22º26'58"N, 114º9'40"E) to Shui Wai (22º27'15"N, 114º9'24"E), and by the water catchment boundary in the south-west. |
| This subzone includes the following areas: Kam Shan, Shek Kwu Lung and Pun Chun Yuen. |