The Public Works Department (JKR) under the Ministry of Development (MoD) issued an apology for the yellow water issue in several areas.
Along with a statement of apology, the department explained, “This issue is usually caused by inconsistent raw water quality, which has high levels of colouration and turbidity, as well as low water pH. However, it has started to decrease.
“The turbidity of raw water sourced from the river often changes, according to the weather. Droughts in the summer and floods in the rainy season are among the factors that can cause water quality to undergo significant changes.”
JKR added that water quality is also affected by heavy rainfall or stagnant water in the water catchment, which can cause changes or an increase in the mineral composition of raw water such as iron, aluminium, sulphide and manganese.
“This situation often occurs when stagnant water starts to seep into the river, which can cause the raw water to give off a bad odour, making it more difficult to treat,” JKR said in its statement.
JKR said, “This requires more detailed supervision and treatment, especially since the dose of chemicals used for water treatment is at optimal level to manage the quality of raw water.
“In addition to chemicals commonly used in water treatment such as calcium carbonate and aluminium sulphate, additional chemicals such as sodium aluminate and polymer are used to help with the process of heavy flocs in sedimentation tanks.
“The treatment plants will always strive to monitor and ensure that the quality of the water supply meets the World Health Organization’s (WHO) standard guideline parameters for clean water.
“Laboratory tests for levels of discolouration, pH, turbidity and chlorine will be performed every two hours daily. In this situation, with a higher rate of contaminated water than usual, the sedimentation and filtration pools require frequent cleaning, resulting in a decreased production of clean water.”
Apart from enhanced treatment efforts, JKR is managing the issue by various operational works such as cleaning water storage tanks, balancing the flow of water to water storage tanks, and flushing water through fire hydrants onto the water distribution system in the affected areas.
Members of the public, especially those with home tanks and private water filters, must ensure that the equipment is in clean condition, through routine flushing and backwashing.
Old tanks and personal water filters that have not been cleaned for a long period can cause discolouration to the tap water inside the house, even if the main water supply is clean.
As an additional precaution, water should be boiled before being used for cooking or drinking.
The public is also urged to conserve water.
Contact the Darussalam hotline at 123 for water tanker services, or for any complaints about the water supply.