 Locating them at Ordnance plants saved the cost of acquiring land, since it was already owned by the government, and they already had personnel and utilities, including steam generating equipment.The three American plants used a process different from Trail's; heavy water was extracted by distillation, taking advantage of the slightly higher boiling point of heavy water.This was not considered to be an efficient process, but it was known to work and scale to an industrial process, and therefore represented less risk than other proposals.