water quality

2. Malaysia’s raw water supply are derived
from :
99% - surface water sources
1% - groundwater source
The most common source drinking
water in Malaysia :
• tap water
• bottled drinking water
• bottled mineral water

3. Water supply from surface water is widely
used as drinking water in Malaysia, such as
water withdraw from Sungai Langat, Sungai
Selangor, Sungai Kinta in West Coast
Peninsular Malaysia.
Water supply from groundwater
also used as drinking water in a few
states of Malaysia such as Kelantan,
Terengganu, Pahang, Perlis, Kedah,
Sabah, and Sarawak.

4. RECOMMENDED RAW
WATER QUALITY
DRINKING WATER QUALITY
STANDARDS
Acceptable Value (mg/litre
(unless otherwise stated))
Maximum Acceptable Value
(mg/litre (unless otherwise stated))
Total Coliform 5000 MPN / 100 ml 0 in 100 ml
E.coli 5000 MPN / 100 ml 0 in 100 ml
Turbidity 1000 NTU 5 NTU
Color 300 TCU 15 TCU
pH 5.5 - 9.0 6.5 - 9.0
Free Residual Chlorine - 0.2 - 5.0
Combined Chlorine - Not Less Than 1.0
Temperature - -
Clostridium perfringens (including spores) - Absent
Coliform bacteria - -
Colony count 22° - -
Conductivity - -
Enterococci - -
Odour - -
Taste - -
Oxidisability - -
Total Dissolved Solids 1500 1000
Chloride 250 250
Ammonia 1.5 1.5
Nitrat 10 10
Ferum/Iron 1.0 0.3
Fluoride 1.5 0.4 - 0.6
Hardness 500 500
Aluminium - 0.2
Manganese 0.2 0.1
Chemical Oxygen Demand 10 -
Anionic Detergent MBAS 1.0 1.0
Biological Oxygen Demand 6 -
PARAMETER
 NDWQS shown in Table 1 was
formulated in 2000 based on World
Health Organisation (WHO)
guideline.
 This standard was used as the water
quality benchmarks of treated water
and raw water which is either
obtained from a water treatment
plant or raw water in Malaysia.
National Drinking Water Standard (KKM, 2009).

5. Groundwater (GW) Surface water (SW)
GW tends to have lower dissolved oxygen
compared to surface water
Dissolved oxygen concentrations vary
depending on organic matter concentrations
Can have very little microbial contamination
especially if GW from a deep aquifer
High turbidity and microbial concentrations
Much higher concentrations of inorganic
compounds (or ions) :
 Anions : chlorides, carbonates,
sulfates/sulphides, bromide, nitrates,
fluorides, arsenite and arsenates
 Cations : Ca, Mg, Fe, Mn, Al, As etc

7. The state governments in
Malaysia are accountable for
the development, operation,
and maintenance
of natural resources, including
water supplies .
Federal government is responsible for
providing soft loans to state
governments for public water supply
infrastructure and grants for rural water
supply development, as water is
essential for the socio-economic
evolution of the nation.

8. Principal Role of Federal
and State Governments
(Malaysia)

9. The process of making water suitable
for desired end use (such as drinking)
Water treatment occurs as a systematic
process through a water treatment plant.

11. Chlorination
• Fresh or sea water
can be chlorinated
using either
chlorine gas or
hypochlorites.
• Chlorinated water
minimizes slime
development on
working surfaces
and helps control
odour.
Ozone
• Needs special equipment,
supply of pure oxygen &
trained operators.
• Ozone is generated by
passing pure oxygen
through an ozone
generator. Then, bubbled
through a gas diffuser at
the bottom of an
absorption column, in a
direction opposite to the
flow of raw water.
Retention or contact time
is critical and the size of
the absorption column
depends on the water flow.
Ultraviolet
treatment
• Often used to treat
drinking water.
Membrane
filtration
• Expensive for
commercial scale
installations.
• Combinations of
membrane
treatment with U-V
treatment units are
available for
domestic use.

12.  Consists of sedimentation &
filtration followed by chlorination.
 Sedimentation can be carried out
by holding the raw water in ponds
or tanks.
 4 basic types of filtration are :

13.  Can be achieved by the addition of lime to
make the water slightly alkaline, followed
by the addition of coagulants like Alum
(aluminium sulphate), ferric sulphate or
ferric chloride.
 The resultant precipitate can be removed
by sedimentation and filtration.
Flocculation, coagulation, sedimentation
and filtration followed by disinfection.
Flocculation and coagulation will assist
in removing contaminants in the water,
causing turbidity, colour odour and
taste which cannot be removed by
sedimentation alone.

14. Chemical treatment may be required to
reduce excessive levels of iron,
manganese, chalk, and organic matter.
Such treatment is usually followed by
clarification.
 Iron : may be removed by aeration
or chlorination to produce a
flocculant which can be removed by
filtration.
 Manganese : may be removed by
aeration followed by adjustment of
pH and up-flow filtration.
 Most colours can be removed by
treatment with ferric sulphate to
precipitate the colours.