Water Quality Control

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:
  - Aluminium Sulphate
- Hydrated Lime
- Polymer
- Chlorine
- Ammonia
- Sodium Silicofluoride
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.
Table 2: Water Quality Standards