Executive Summary

On October 26, 2019, an Aghorn Operating Inc. (Aghorn) employee, Pumper A, responded to a pump oil level alarm at Aghorn's Foster D waterflood station in Odessa, Texas. The pump (called Pump #1) was located in a building called a pump house. In response to the alarm, Pumper A worked to isolate the pump from the process by closing the pump's discharge valve and partially closing the pump's suction valve. Pumper A did not first perform Lockout / Tagout to isolate Pump #1 from energy sources before performing work on the pump. At some point on the night of the incident, the pump automatically turned on, and water containing hydrogen sulfide (H2S), a toxic gas, released from the pump. The CSB found post-incident that the pump had a broken plunger from which the water and H2S released. Due to the limitations of the available evidence, the CSB was unable to determine whether the pump failure and loss of containment of the produced water (1) occurred before Pumper A arrived at the facility, or (2) occurred when the pump energized while Pumper A was closing valves to isolate the pump.

Pumper A was fatally injured from his exposure to the released H2S.

Subsequently, the spouse of Pumper A gained access to the waterflood station and searched for Pumper A. During her search efforts, she also was exposed to the released H2S and was fatally injured.

Odessa Fire Rescue and the Ector County Sheriff's Office responded to the incident. Federal agencies that investigated the incident include the Occupational Safety and Health Administration (OSHA) and the U.S. Chemical Safety and Hazard Investigation Board (CSB).

The CSB's investigation identified the safety issues below.

Safety Issues

The investigation evaluated the following safety issues:

• Nonuse of Personal H2S Detector. Pumper A was not wearing his personal H2S detection device upon entering the waterflood station on the night of the incident, and there is no evidence that Aghorn management required the use of these devices. (Section 3.1)

• Nonperformance of Lockout / Tagout. At the time of the incident, Aghorn did not have any written Lockout / Tagout policies or procedures. Pumper A did not perform Lockout / Tagout to deenergize Pump #1 before performing work on it. The automatic activation of the pump allowed water containing H2S to release from the pump. (Section 3.2)

• Confinement of H2S Inside Pump House. The pump house could be ventilated by two bay doors on the east side of the pump house, exhaust fans on the west wall opposite of the bay doors, and natural vents on each of the four outside walls. Due to the limitations of the available evidence, the CSB was unable to confirm whether the exhaust fans were operational at the time of the incident. On the night of the incident, the bay doors were approximately 60% open. The available ventilation methods did not adequately ventilate toxic H2S gas from the building during the incident, contributing to the high H2S levels to which Pumper A and his spouse were exposed. (Section 3.3) 

• Lack of Safety Management Program. The CSB requested from Aghorn "all written policies and procedures used by Aghorn Operating." Aghorn's response included: 1) a cell phone use policy, 2) an alarm call out procedure, 3) a Lockout / Tagout policy and procedure that was created post-incident, and 4) a pamphlet on H2S hazards. Aghorn had no additional formal company safety or operational policies or procedures. (Section 3.4)

• Nonfunctioning H2S Detection and Alarm System. The pump house was equipped with an H2S detection and alarm system. However, the H2S control panel did not receive signals from the internal and external detection sensors at the facility, and, therefore, did not trigger either of the two H2S alarms on the night of the incident. (Section 3.5)

• Deficient Site Security. As per Aghorn's informal policy, when an Aghorn employee is working at the facility, the access gates are normally left unlocked. The unlocked gates allowed Pumper A's spouse to drive directly to the waterflood station and enter the pump house, where she was exposed to toxic H2S gas. (Section 3.6)