- dike wall:New Storage tanks area has to be provided with dike wall with safe capacity margin, not less than (150%) of the capacity of the largest tank in the farm area.Storage tanks shall locate within a containment area surrounded by a dike wall. In the event of a tank leak, the contents of the tank will be contained with the diked area. Containment of the spill is required to prevent the tank contents from escaping into the environment and enable the controlled recovery, treatment or disposal of the spill.The contractor shall consider that the minimum distance of the dike wall or berm to the edge of the tank is important to ensure that a tank leak is contained properly. Calculations has to perform to determine the distance the acid will travel and the distance and height of the berm should be sufficient to contain the acid.