Drinking Water Storage Tanks
Storage of Water. This is best accomplished, if it can be so arranged, in underground tanks (see picture 55), as it is thus rendered more palatable by its power of assimilating carbonic acid gas, but care must be taken that there is no possibility of pollution.
Domestic cisterns of lead should be avoided for soft-water storage, owing to the danger of the water carrying away the soluble oxide of lead formed by the action of oxygen. The lime in hard water, however, forms a protective surface on the lead and there is thus less danger in using it. Iron treated with a coating of zinc (known as galvanized iron) should not be used, as most waters will dissolve this coating sooner or later.
Slate and earthenware cisterns should be used wherever possible. Cisterns must be cleaned out regularly, for they become a depositing ground for impurities in the water supply. All cisterns should be covered to prevent their pollution by dust, dirt and possibly by dead mice and birds, and they should always be ventilated. An overflow pipe should be provided with its open end as far as possible from any likely contamination and in such a position that any waste of water may be at once noticed.
Next: Water Hardness.