Actually, as per the dumping protocol, dump runs were supposed to be done with two vehicles. One parked at the edge of the pit to offload waste containers and another parked at a distance so that, in the advent of an explosion disabling the offloading truck, there was a second vehicle intact to provide transportation. (8) 

       One inspection report dated 12/11/74 stated: 

“Fires and explosions do occur in the pit. Thick acid smoke is also produced. A violet(sic) explosion did occur during this inspection that did result in injury. The explosion may also have caused damage to the U. of A. pick up which is equipped with a 55 gal. water barrel plus pump and hose. The fallout of chemicals was rather minor. This inspection(sic) was actually blown off his feet by the explosion. Potential disaster was averted because the explosion was downward which increased the size of the pit. There was some flying glass and metal. Generally the explosion(sic) are usually small, but this one was a dilly. There is some pollution (air) danger to humans and animals.” (5) 

       In reality, fires were intentionally set. Internal documents state: “ 
 

“The chemicals frequently self-ignite. If the chemicals do not self-ignite and there is any danger that they may explode later the chemicals are ignited.” (6)

        At times, the resulting pit fires produced substantial plumes of thick black smoke. In April of 1978, documented in an UA Memorandum from Bob Dorsey to John B. Trimble (77), one such plume was spotted by the Golder Fire station in Catalina, which in turn notified the Pinal County Sheriff’s Department. They investigated it as a possible plane crash. Through a phone call to Davis Monthan Air Force Base, the