When dealing with portable equipment, it is sometimes tricky to know who to permit it with: the local air district or the California Air Resources Board. The answer mostly depends on where and for how long you will operate the equipment. In May of 2016, TES, Inc. prepared a permit application for a portable off-loader unit with the South Coast AQMD. Although portable, the equipment needed to be able to remain at one location for more than 12 months and had minimum production requirements.