Water Storage Tank Cleaning for High-Rise Building

Water Storage Tank Cleaning for High-Rise Building

Water Storage Tank Cleaning for High-Rise Building

The places such as hotel, hospital, etc., usually found high demand of water consumption at the same time. So water storage tank has to be provided to reserve sufficient water supply. However, treated water kept for a long time in the storage tank might not be found any residual chlorine or contamination might be occurred by foreign matter from outside. Water from water storage tank often found bacteria causes inflammation in stomach and intestines or found other quality factors of water supply in building that not meets the Water quality standards of Metropolitan Waterworks Authority (MWA). To prevent mentioned problems, MWA recommended to clean water storage tank every 6 months. K-Wiz work procedures following MWA standards are shown as below;

  • Before cleaning the water tank, we collect water sample to test water quality limits on the following water quality parameters:

    • Turbidity less than 4 NTU
    • Free residual chlorine in the range of 0.2 to 0.5 mg/L
    * Refer to announcement of Department of Health, Ministry of Public Health

  • Pump the remaining water out of the water tank


  • Measure the oxygen level in the water tank which is considered as confined space. Add the oxygen by fan to control the oxygen concentration in range of 19% (v/v) to 23.5% (v/v)


  • Tank walls, all machines and accessory in tank are cleaned by high pressure water jet and workers who have trained to work in confined space from organizations certified by Department of Labour Protection and Welfare, the Ministry of Labour (MOL)


  • Collect water sample to test water quality after cleaning