| (Cap 358 section 5) [28 May 1993] (L.N. 171 of 1993) Cap 358AA s 1 The water quality objectives set out in column 1 of the Schedule are established for those parts of the Eastern Buffer Water Control Zone set opposite those water quality objectives in column 2. (Enacted 1993) Cap 358AA s 2 In this Statement- "Fish Culture Subzone" (鱼类养殖分区) means an area of water designated as a fish culture zone under the Fish Culture Zone (Designation) Order (Cap 353 sub. leg.) and situated in the Eastern Buffer Water Control Zone; "Map" (地图) means a map marked EBWCZ described as "Eastern Buffer Water Control Zone", signed by the Secretary for Planning, Environment and Lands on 19 May 1993 and deposited in the Land Registry, Victoria; "marine waters" (海洋水域) means all waters below the high water mark within the boundary of the Eastern Buffer Water Control Zone; "other inland waters" (其他内陆水域) means inland waters other than those in the Water Gathering Ground Subzones; "Water Gathering Ground Subzone" (集水地区分区) means an area delineated as such on the Map. (Enacted 1993) Cap 358AA SCHEDULE [section 1] Water Quality Objective Part of Parts of Zone A. AESTHETIC APPEARANCE (a) There should be no objectionable odours or discolouration of the water. (b) Tarry residues, floating wood, articles made of glass, plastic, rubber or of any other substances should be absent. (c) Mineral oil should not be visible on the surface. Surfactants should not give rise to a lasting foam. (d) There should be no recognisable sewage-derived debris. (e) Floating, submerged and semi-submerged objects of a size likely to interfere with the free movement of vessels, or cause damage to vessels, should be absent. (f) The water should not contain substances which settle to form objectionable deposits. Whole zone Whole zone Whole zone Whole zone Whole zone Whole zone B. BACTERIA (a) The level of Escherichia coli should not exceed 610 per 100 mL, calculated as the geometric mean of all samples collected in a calendar year. (b) The level of Escherichia coli should be less than 1 per 100 mL, calculated as the geometric mean of the most recent 5 consecutive samples taken at intervals of between 7 and 21 days. (c) The level of Escherichia coli should not exceed 1000 per 100 mL, calculated as the geometric mean of the most recent 5 consecutive samples taken at intervals of between 7 and 21 days. Fish Culture Subzones Water Gathering Ground Subzones Other inland waters C. COLOUR (a) Human activity should not cause the colour of water to exceed 30 Hazen units. (b) Human activity should not cause the colour of water to exceed 50 Hazen units. Water Gathering Ground Subzones Other inland waters D. DISSOLVED OXYGEN (a) The level of dissolved oxygen should not fall below 4 mg per litre for 90% of the sampling occasions during the whole year; values should be calculated as water column average (arithmetic mean of at least 3 measurements at 1 m below surface, mid-depth and 1 m above seabed). In addition, the concentration of dissolved oxygen should not be less than 2 mg per litre within 2 m of the seabed for 90% of the sampling occasions during the whole year. (b) The level of dissolved oxygen should not be less than 5 mg per litre for 90% of the sampling occasions during the year; values should be calculated as water column average (arithmetic mean of at least 3 measurements at 1 m below surface, mid-depth and 1 m above seabed). In addition, the concentration of dissolved oxygen should not be less than 2 mg per litre within 2 m of the seabed for 90% of the sampling occasions during the whole year. (c) The level of dissolved oxygen should not be less than 4 mg per litre. Marine waters excepting Fish Culture Subzones Fish Culture Subzones Water Gathering Ground Subzones and other inland waters E. pH (a) The pH of the water should be within the range of 6.5-8.5 units. In addition, human activity should not cause the natural pH range to be extended by more than 0.2 units. (b) Human activity should not cause the pH of the water to exceed the range of 6.5-8.5 units. (c) Human activity should not cause the pH of the water to exceed the range of 6.0-9.0 units. Marine waters Water Gathering Ground Subzones Other inland waters F. TEMPERATURE Human activity should not cause the natural daily temperature range to change by more than 2.0 degrees Celsius. Whole zone G. SALINITY Human activity should not cause the natural ambient salinity level to change by more than 10%. Whole zone H. SUSPENDED SOLIDS (a) Human activity should neither cause the natural ambient level to be raise by more than 30 % nor give rise to accumulation of suspended solids which may adversely affect aquatic communities. (b) Human activity should not cause the annual median of suspended solids to exceed 20 mg per litre. (c) Human activity should not cause the annual median of suspended solids to exceed 25 mg per litre. |
