128. On March 23, 1982, drainage ceased because of sludge blocking the valve at the bottom of the tank. (U)
129. To clear the sludge from the valve and allow drainage to continue, OH Materials personnel inserted rods through the manway at the top of the oleum tank. (U)
130. The rods were inserted with the knowledge of the EPA.
131. Following this insertion of rods through the manway, on March 23, 1982, at 3:57 P.M., a steam explosion occurred in the oleum tank. (U)
132. A large cloud of sulfer trioxide and sulfuric acid, in the form of droplets, mist and aerosol, vented out of the manway at the top of the tank. (U)
133. The release occurred over approximately a 15 second span. (U)
134. The release was punctuated by three distinct explosions. (U)
135. The cloud of sulfer trioxide and sulfuric acid rose approximately 40 to 50 feet into the air.
136. The oleum tank bounced approximately one inch off its pedestals several times during the course of the explosive release of March 23, 1982.
137. The oleum tank displayed no apparent damage from the explosion.
138. South-southwest winds were prevailing on March 23, 1982, blowing generally north-northeast. (U)
139. Blown by the wind, the acid cloud released from the oleum tank migrated off site into the City of Lock Haven.
140. The acid cloud of March 23, 1982, caused surface damage to over 500 motor vehicles, damaged an airplane, and damaged several buildings. (U)
141. On behalf of OH Materials, U.S.F. & G. paid claims totalling $ 133,296.27 arising out of the release of the acid cloud of March 23, 1982.
142. U.S.F. & G. hired Crawford and Company to adjust the claims arising out of damage caused by the acid cloud of March 23, 1982.
143. The hiring of Crawford and Company facilitated the prompt settlement of property damage claims arising out of the acid release incident of March 23, 1982.
144. On March 24, 1982, the On Scene Coordinator met with officials from the Department of Environmental Resources, and agreed that work prone to release of vapors would be done only on good dispersion days between 10:00 A.M. and 5:30 P.M., and on days when the wind was not blowing toward the City. (U)
145. Following the incident of March 23, 1982, the interior of the oleum tank was inspected through the use of mirrors and a camera. (U)
146. Visual inspection and photographic examination of the inside of the tank showed a residual crust line approximately halfway up the side of the tank. (U)
147. Based on the acid release of March 23, 1982 and the investigation conducted subsequent to the release, it can reasonably be concluded that the tank was roughly one-half full of 65% oleum. (U)
148. It is estimated that in the March 23, 1982 release incident, approximately 2,000 gallons of oleum reacted with 2,000 gallons of water to produce 4,000 gallons of 80% sulfuric acid. (U)
149. In the March 23, 1982 release incident, approximately 2,000 gallons of 80% sulfuric acid were vented through the manway of the tank.
150. Removing the oleum tank from the pedestals on which it sat and placing it on the ground at the rear of the site prior to neutralization would have had the following advantages over performing neutralization with the tank on its pedestals:
A. The contents of the tank could have been more accurately and easily measured;