Kuching Water Board uses the conventional method in the treatment of raw water from Sungai Sarawak Kiri. The typical raw water is slight turbid and has a pH value of about 6.9. The treatment processes deployed are as follows:
a.
Coagulation - Destabilizations of colloidal matters to form micro-floc
b.
Flocculation - Agglomeration of micro-floc to form larger floc
c.
Sedimentation - Settlement of floc by gravity
d.
Filtration - Solid-liquid separation through porous media
e.
Disinfection - Elimination of bacteria by using chloramines (chlorine and ammonia)
f.
Fluoridation - Addition of fluoride to prevent dental caries
g.
Conditioning - Elevation of pH value in drinking water
The water treatment chemicals used in the treatment process are as below:
To ensure that the drinking water produced by Kuching Water Board consistently complies with the National Drinking Water Quality Standards a system of stringent water quality surveillance programme has been instituted. The programme prescribes the frequency, type and location of water samples to be collected from the raw water sources, water in the treatment train, reservoirs and 40 other sampling stations that are strategically located in the water supply area. The locations of the sample stations are as shown in Table 1 below:
Water samples collected three time a month at every location
No.
Location
No.
Location
1
Kampung Semaba
21
Kampung Kuap
2
Jalan Datuk Stephen Yong
22
16th Mile Jalan Serian
3
Taman Malihah
23
10th Mile Bazaar
4
11th Mile Jalan Matang
24
Jalan Stakan
5
Polytechnic
25
Kampung Merdang
6
Matang Wild Life Centre
26
Kampung Meranek
7
Kampung Telaga Air
27
Kampung Pinang
8
6th Mile Jalan Matang
28
Kota Samarahan Market
9
Kubah Ria, Jalan Matang
29
Kampung Baru
10
General Hospital
30
15th Mile Jalan Serian
11
Rubber Road
31
Batu Kawa
12
Market Street
32
Jalan Sungai Tapang
13
Normah Hospital
33
Taman Satria Jaya BDC
14
Institut Kemahiran Mara
34
Hui Sing
15
Petra Jaya
35
Tabuan Jaya
16
Kampung Sejingkat
36
Tabuan Laru
17
Kampung Senari
37
Pending/Bintawa
18
Kampung Gobel
38
Bintawa Industrial Estate
19
Bako Resettlement Scheme
39
Pending
20
Muara Tebas
40
Sama Jaya Industrial Park
Water samples are sent to both the Department of Chemistry in compliance with the Ministry of Health’s National Drinking Water Quality Surveillance Programme and Kuching Water Board’s Water Quality Assurance Laboratory for analysis. The analysis includes physico-chemical and bacteriological examination.
In 2007, a total of 27,036 water samples were collected from the raw water sources, treatment plant pumping mains, reservoirs and distribution system for physico-chemical and bacteriological examination. Out of the number, 20682 samples were analyzed physicochemically while the remaining 6354 samples were examined bacteriological. A total of 25252 samples or 93.4 % of the total were analyzed in the Board’s Water Quality Control Laboratory while the rest of the 1748 samples or 6.6% were sent to the Department of Chemistry for analysis. The breakdown of the samples analyses in 2007 is as shown in Table 2 below:
