1.0 PURPOSE:
2.0 SCOPE:
This procedure for cleaning of water tanks is applicable to water tanks which are being used for purified water system at (Company name).
(Note: Not applicable for purified water storage tanks).
3.0 DEFINITION:
4.0 RESPONSIBILITY:
Execution: Personnel of Engineering Department.
Checking: Personnel of Engineering Department.
Accountability: Head-Engineering/ Designee.
5.0 FREQUENCY:
6.0 PROCEDURE:
6.1 Water from the tank shall be emptied out completely.
6.2 Side walls of the tank and also bottom of the tank shall be cleaned manually using nylon brush.
6.3 Sufficient amount of potable water/purified water shall be added in the tank and the walls of the tank shall be brushed with hard nylon brush to remove any residue if any. Then the water shall emptied out completely from tank.
Note: For cleaning of RO permeate water tank only purified water shall be used instead of potable water.
6.4 After that the tank shall be washed twice with sufficient amount of potable water/purified water and the water shall be emptied completely.
6.5 Mixture of potable water/purified water and sodium hypochlorite (NaOCl – 5% to 7%) with solubility 7.5% shall be prepared and spread in the interior of the tank and allowed to stand for 30 minutes and then the water shall be emptied completely and after that the tank is washed thrice with potable water.
6.6 Apply 10 to 15 liters of potable water/purified water on tank walls, collect the water sample from bottom of the tank and check the chlorine content for not more than 1 ppm. Then fill the tank with required quantity of water.
6.7 Cleaning of the water tanks shall be performed as per the schedule and details of tank cleaning shall be recorded.
6.8 After tank cleaning, cleaning tag shall be updated on the tank.
7.0 ABBREVIATIONS:
ppm : Parts per million
RO : Reverse osmosis