Do I Need to Clean & Chlorinate My Cold Water
The Cleaning and chlorination of cold Water tanks
Sometimes this is not the case. Systems that are badly designed, are in a poor state of general repair or are operated at unsuitable temperatures can become a breeding ground for a variety of bacteria.
Within the system, dirt, scale and debris can act as a source of nutrients for bacteria. Water Tanks are required to be inspected every 6 and 12 months. The ACoP L8 require this:-
From ACoP L8
Visually inspect cold water storage tanks and carry out remedial work where necessary. Check representative taps for temperature as above on a rotational basis
You can see it does not say clean tanks its says carry out work where necessary. The picture below show some tanks that did need cleaning
These tanks failed the inspection because of missing lids and screen kits, also called a bylaw 30 kit. (Screwfix Cold Water Storage Tank Byelaw 30 Kit Product Code: 20864 £5:99 inc vat )
I suggest the 1st thing you do before paying out £300 for chlorination work is make sure the tank is covered with a well fitting lid (£15 ) A local plumber can fit the lid and fit the screen kit and insulate the the whole cold water tank. The work should include a, finally covering with a plastic sheet.(this plastic sheet will make inspection work less likely to contaminate the tank when the lid is removed for 6 monthly inspection)
Do not jump to cleaning find out why and how the tank became contaminated in the 1st place. Remember all water carries silt and this will build up over time. This silt is no indication of the cleanliness of the tank.
What to do:-
1st Analysis of the tank should be carried out (TACC water test £30 to see if you have contamination issue). If the analysis comes back clear then you may not need an expensive clean out.
2nd Is the water used for drinking ? This is about risk if no one cannot drink the water, then its not a risk. Or is it sterilized or pasteurised by your hot water system again this reduces the risk.
3rd Would the money be better spent on a new tank or convert the building to mains fed hot water system or Combi boiler ?. This would eliminate future tank cleaning and reduce your enegy bills
4th Implement an action plan, for planned maintenance. Tank cleaning can cause loss of hot and cold water in your building for an minimum of 2 hrs. Have work done in combination with other planned maintainence to reduce inconveience to your site.
5th Ask for pictures to show the contamination before and after the cleaning.