High Quality Content by WIKIPEDIA articles! Water tanks are liquid storage containers, these tanks are usually storing water for human consumption. THe need for water tank systems is as old as civilized man. A Water tank provides for the storage of drinking water, irrigation agriculture, fire suppression, agricultural farming and livestock, chemical manufacturing, food preparation as well as many other possible solutions. CHemical contact tanks of FDA and NSF polyethylene construction, allow retention time for water treatment chemicals to be in contact with product water. (black tank in foreground).