State of the Bay Report 2011-Final.pdf - Anchor Environmental

State of Saldanha Bay & Langebaan Lagoon 2011
Activities & discharges
Historically a number of these pump stations used to overflow from time to time directly
into the Bay when the pumps malfunctioned. This is now a rare event, however, as much of the
associated infrastructure has been upgraded recently and is now regularly maintained.
The Saldanha WWTW operates under an exemption issued by the Department of Water
Affairs (DWAF) in terms of the Water Act of 1956 which authorises the release of a total volume of
958 000 m 3 per year. The volume of waste water that is permitted to be released from the
Langebaan WWTW is unknown at this stage. Up until recently at least, most of the waste water
from this plan was used to irrigate the golf course. Table 3.5 shows the general standards as
specified under the Water Act 54 (1956), and the revised general limits specified under the National
Water Act 36 of 1998 for various other parameters and substances contained in the released waters
of the WWTW of Saldanha and Langebaan.
Table 3.5.
General standards as specified under the Water Act 54 (1956) and revised general limits
specified under the National Water Act 36 of 1998.
Substance/parameter
General standards under
the Water Act (1956)
General limit for general
authorisation under the
National Water Act (1998)
Temperature 35 o C -
Electrical Conductivity measured in milliSiemens
per meter (mS/m)
75
70 above intake to a
maximum of 150
pH 5.5-9.5 5.5-9.5
Chemical Oxygen Demand (mg/l) 75 75 (after removal of algae)
Suspended Solids (mg/l) 25 25
Soap, oil or grease (mg/l) 2.5 2.5
Ortho-Phosphate as P (mg/l) - 10
Nitrate/Nitrite as Nitrogen (mg/l) - 15
Ammonia (ionised and un-ionised) as N (mg/l) 10 3
Fluoride (mg/l) 1 1
Chlorine as Free Chlorine (mg/l) 0.1 0,25
Dissolved Cyanide (mg/l) 0.5 0.02
Dissolved Arsenic (mg/l) 0.5 0.02
Dissolved Cadmium(mg/l) 0.05 0.005
Dissolved Chromium (VI) (mg/l) 0.05 0.05
Dissolved Copper (mg/l) 1 0.01
Dissolved Iron (mg/l) - 0.3
Dissolved Lead (mg/l) 0.1 0.01
Dissolved Manganese (mg/l) 0.4 0.1
Mercury and its compounds (mg/l) 0.02 0.005
Dissolved Selenium (mg/l) 0.05 0.02
Dissolved Zinc (mg/l) 5.0 0.1
Boron (mg/l) 1 1
Phenolic compounds as phenol (mg/l) 0.1 -
Faecal Coliforms (per 100 ml) 100 1000
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