Cleaning and disinfecting water storage tanks and tankers : WHO technical note for emergencies No. 3

It is often necessary to quickly provide a basic water supply during and shortly after an emergency. This
may be because the normal supply has been damaged or destroyed, or because people collect in a place where no water supply exists (a new refugee camp, for example). Often the quickest way of providing a water supply is to transport water in tankers from a nearby source and store the water in tanks and reservoirs. However it is rare for water tankers and reservoirs to be readily available in such situations. The most common solution is to hire vehicles and tanks that have been used for other purposes but they must be cleaned and disinfected before they can be used.

(authors abstract)