CSB Says Inadequate Storage Management Caused 2009 CAPECO Explosion

CSB has released its draft investigation report into the 2009 explosion at the Caribbean Petroleum

Photo Courtesy: CSB

Corporation (CAPECO) terminal facility in Bayamón, PR. It includes proposed recommendations for addressing regulatory gaps in safety oversight of petroleum storage facilities by OSHA and EPA. The
proposed regulatory changes would affect the EPA’s Risk Management Program; Spill Prevention, Control and Countermeasure (SPCC) rules; and OSHA’s Flammable and Combustible Liquids standard.

On Oct. 23, 2009, gasoline overflowed and sprayed out from a large aboveground storage tank at the facility, forming a 107-acre vapor cloud that ignited. No one was killed, but the explosion damaged approximately 300 nearby homes and businesses, and petroleum leaked into the surrounding soil, waterways and wetlands.

The measuring devices used to determine the liquid levels in the tanks were poorly maintained and in many cases not working. The facility primarily measured tank levels using simple mechanical devices consisting of a float and automatic measuring tape. An electronic transmitter card was supposed to send the liquid level measurements to the control room. The transmitter card on one tank was out of service, requiring operators to manually record the hourly tank level readings.

CSB Board Member Mark Griffon says, “CSB’s investigation determined that there are a number of shortcomings in regulations that cover petroleum storage facilities. Facilities such as CAPECO, which store large quantities of gasoline and other flammables, are not required to conduct a risk assessment of potential dangers to the nearby community from their operations.”

The report also says that an independent, high-level alarm could have detected and alerted operators to the danger of an overfill, even if the primary system for measuring the tank level failed. An automatic overfill prevention system, which CAPECO did not use, can shut off or divert the flow into a tank when the tank level is critically high.

It also recommends that EPA adopt new regulations for facilities like CAPECO to require that flammable storage tanks be equipped with automatic overfill protection systems, and to require regular testing and inspection as well as risk assessments. CSB is also suggesting similar recommendations to OSHA, American Petroleum Institute, and two key fire code organizations.