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Chlorination of a household tank


We have a water tank that is filled daily using a pump; the water is directly from the well, and contains small worms. Would chlorination be a solution to clean the water? How often and how much would have to be placed in the water? The tank is about 200 litres..



4 Answers


If there are small worms that are visible to the naked eye then you need some sort of filtration in addition to chlorination. The filtration could be a simple gravity sand filter or a ceramic filter.

A sand filter could be made out of in an oil drum filled with sand. Water would flow in at the top and be collected from the bottom. Part of the treatment comes from biological action by bacteria that develops in the top layer of sand (exposed to sunlight) and this would clog up periodically and have to be replaced.

Chlorination would be necessary. There are guidelines in several books that I have at home but unfortunately I am currently working in Namibia. They are probably in the RedR book "Engineering in Emergencies". It depends on the volume of water and the strength of the chlorine used. Water should be allowed to stand for a few hours after chlorination to allow the chlorine time to kill bacteria before it is drunk.




As a rule of thumb, if you can taste the chlorine it is a slightly stronger solution than it needs to be.

Strictly speaking depends on turbidity and pH levels, but buying chlorine tablets and following their guidance will be close

Alternatively Merlin Sierra Leone used a domestic ceramic candle filter




For the Liberian well, I'd pump out the well, scrub down the walls with a 0.02% chlorine solution, leave it to fill again with water, adding sufficient chlorine to create a 0.02% chlorine solution in the well, leave for 12 hours and then pump out the well again until there is only a faint chlorine smell. Not to forget cleaning out and disinfecting the tank in a similar way if it's not been done for a while.

Regards, John


This type of slow sand filter springs to mind but maintenance is going to be a problem with this type of user???

Small scale water treatment plant. Suitable for villages, Manor Houses e.g. National Trust type Properties, fish-farms, swimming pools, mountain lodges, mines etc. Capacity 12.5cu m per day, sufficient to supply 500 people with drinking water @ 25lpp/d. Requires no electricity or chemicals.