Would you brush your teeth in this ? No, not knowingly but one of my new customers had been.
A cold water storage vessel (c.w.s.v.) should be fitted correctly and to current regulations.
A lid is a must, not a piece of wood or some polystyrene but a fitted lid which is made for that c.w.s.v.
Also it should be sized correctly to make sure there is enough stored water for your needs but not too much where it could become stagnant.
At this property there were two vessels connected together which held too much water for the owners to use.
We have sent an estimate for a new c.w.s.v installation.