Iron sponge gas treating units processing streams containing less than 60 pounds per hour of hydrogen sulfide are permitted by rule provided that the following conditions of this section are satisfied:(1) the plant is located at least 1/4 mile from any recreational area or residence or other structure not occupied or used solely by the owner of the facility or the owner of the property upon which the facility is located;(2) during replacement of the iron oxide impregnated chips, the unit is:(A) isolated from the main system and the pressure is reduced to 0.5 psia or less through a gas-fired flare; or(B) sulfur compound emissions to the atmosphere do not exceed one ton per replacement;(3) the spent iron oxide chips being replaced are properly handled to avoid spontaneous ignition and avoid an odor nuisance.