A steel tank used to store sewage sprang a leak during the event in 2014.

It has to be softened with yet another catalyst (this time usually sodium) in yet another sealed steel tank, in a process known as interesterification.

Tanks larger than four meters are generally limited by shipping constraints, and the economics suggest a concrete or steel tank fabricated at the tank's location.

Steel tank rectifiers frequently required vacuum pumps which continually emitted small amounts of mercury vapor.

Tests on the remnants of the steel tank revealed microscopic stress cracks consistent with corrosion caused by previous loads of improperly overpressurized anhydrous ammonia.