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Chapter:

358L PDFTitle:JUNK BAY WATER CONTROL ZONE STATEMENT OF WATER QUALITY OBJECTIVESGazette Number:
Schedule:1Heading:Version Date:30/06/1997

Water Quality Objective
Part or parts of Zone
      A. AESTHETIC APPEARANCE
      (a) Waste discharges shall cause no objectionable odours or discolouration of the water.
      (b) Tarry residues, floating wood, articles made of glass, plastic, rubber or of any other substance 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 recognizable 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) Waste discharges shall not cause the water to Whole Zone 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 one calendar year.

      (b) (Repealed L.N. 451 of 1991)
      (c) The level of Escherichia coli should not exceed 1000 per 100 ml, calculated as the running median of the most recent 5 consecutive samples taken at intervals of between 7 and 21 days.
    Secondary Contact
    Recreation Subzone and Fish Culture Subzones (L.N. 451 of 1991)

    Inland waters
      C. COLOUR
      Waste discharges shall not cause the colour of water to exceed 50 Hazen units.
    Inland waters
      D. DISSOLVED OXYGEN
      (a) Waste discharges shall not cause the level of dissolved oxygen to fall below 4 mg per litre for 90% of the sampling occasions during the year; values should be calculated as the 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 year.
      (b) The dissolved oxygen level 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 year.
      (c) Waste discharges shall not cause the level of dissolved oxygen to be less than 4 mg per litre.
    Marine waters excepting Fish Culture Subzones







    Fish Culture Subzones








    Inland waters
      E. pH
      (a) The pH of the water should be within the range of 6.5-8.5 units. In addition, waste discharges shall not cause the natural pH range to be extended by more than 0.2 units.
      (b) (Repealed L.N. 451 of 1991)
      (c) The pH of the water should be within the range of 6.0-9.0 units.
    Marine waters (L.N. 451 of 1991)



    Inland waters
      F. TEMPERATURE
      Waste discharges shall not cause the natural daily temperature range to change by more than 2.0 degrees Celsius.
    Whole Zone
      G. SALINITY
      Waste discharges shall not cause the natural ambient salinity level to change by more than 10%.
    Whole Zone
      H. SUSPENDED SOLIDS
      (a) Waste discharges shall neither cause the natural ambient level to be raised by 30% nor give rise to accumulation of suspended solids which may adversely affect aquatic communities.
      (b) Waste discharges shall not cause the annual median of suspended solids to exceed 25 mg per litre.
    Marine waters



    Inland waters
      I. AMMONIA
      The ammonia nitrogen level should not be more than 0.021 mg per litre, calculated as the annual average (arithmetic mean), as unionized form.
    Whole Zone
      J. NUTRIENTS
      (a) Nutrients shall not be present in quantities sufficient to cause excessive or nuisance growth of algae or other aquatic plants.
      (b) Without limiting the generality of objective (a) above, the level of inorganic nitrogen should not exceed 0.3 mg per litre, expressed as annual water column average (arithmetic mean of at least 3 measurements at 1 m below surface, mid-depth and 1 m above seabed).
    Marine waters


    Marine waters
      K. 5-DAY BIOCHEMICAL OXYGEN DEMAND
      Waste discharges shall not cause the 5-day biochemical oxygen demand to exceed 5 mg per litre.
    Inland waters
      L. CHEMICAL OXYGEN DEMAND
      Waste discharges shall not cause the chemical oxygen demand to exceed 30 mg per litre.
    Inland waters
      M. DANGEROUS SUBSTANCES
      (a) Waste discharges shall not cause the concentrations of dangerous substances in the water to attain such levels as to produce significant toxic effects in humans, fish or any other aquatic organisms, with due regard to biologically cumulative effects in food chains and to toxicant interactions with each other.
      (b) Waste discharges of dangerous substances shall not put a risk to any beneficial uses of the aquatic environment.
    Whole Zone





    Whole Zone
      N-O. (Repealed L.N. 451 of 1991)

(Enacted 1989)