Any lime slaking facility used to mix quicklime with water is permitted by rule, provided the following conditions of this section are met:(1) the mixing vessel shall be horizontal;(2) the mixing vessel shall use interior mechanical agitation parallel to the bottom and agitate the water over the full length of the vessel;(3) quicklime shall be injected into the mixing vessel as follows:(A) where injection is from a pneumatic transfer system, the quicklime shall be injected at a point at least 12 inches under the surface of the agitated water; or(B) where injection is from a non-pneumatic conveying system unloading at the top of the vessel, emissions from any vent on the vessel shall be controlled by an appropriately sized wet scrubber;(4) there shall be no visible emissions (other than uncombined water).