0847 hours this morning, Fire, EMS, from Waldorf and surrounding companies responded to a reported "ammonia leak" from a location within the Capital Clubhouse Recreation Center 3033 Waldorf Market Place. E31 arrived and reported "building has not been evacuated, a white cloud coming out the back of the building". Duty Officer #3 (Jenkins) arrived, established "command" and immediately ordered evacuation of the Capital Clubhouse and the surrounding "strip mall stores" that are within 200'. With the "hot zone" established and with the assistance of CCSO and responding Fire EMS units the evacuation was completed in 15 minutes ensuring the complete safety of the public in the area. Command request assistance from Fairfax County Special Hazards Response Unit (SHRU437) while the Charles County HazMat team with mutual aid from NDW Indian Head Haz Mat developed a "strategy" and went into the building utilizing complete Haz Mat personal protection to identify the location and equipment needed to secure the ammonia leak. Units located the source, secured and began lengthy ventilation process. Two persons were treated by EMS members, not requiring transport. Command terminated at 1455 hrs. No injuries to Fire/EMS