All surface water and some groundwaters require treatment prior to consumption to ensure that they do not represent a health risk to the user. Health risks to consumers from poor quality water can be due to microbiological, chemical, physical or radioactive contamination. However, microbiological contamination is generally the most important to human health as this leads to infectious diseases which affect all populations groups, many of which may cause epidemics and can be fatal. Chemical contamination, with the exception of a few substances such as cyanide and nitrate, tends to represent a more long-term health risk. An example of this is nitrate which can cause methaemoglobinaemenia in babies. Substances in water which affect the clarity, colour or taste of water may make water objectionable to consumers and hence ability to recover costs. As many microorganisms are found associated with particles in water, physical contamination may also represent a health risk as it extends microbial survival. Most treatment systems are designed to remove microbiological contamination and those physical constituents which affect the acceptability or promote microorganism survival largely related to the suspended solids in the water. A disinfectant is nearly always included in treatment plants of any size.
Pinang Tunggal water treatment plant produce 227,000 cubic meter per day of treated water. The source of raw water for the plants is from the Muda Dam through the Muda River.
Their main role of Pinang Tunggal water treatment plant is to inactivate any remaining bacteria as the final unit of treatment and, more importantly to provide a residual disinfectant which will kill any bacteria introduced during storage and or distribution. Pinang Tunggal water treatment distribute treated water to North and South Sungai Petani, Gurun, Tikam Batu and Pantai Merdeka or can said all over Kuala Muda Yan.
There are 8 main process for water treatment at plant which is :