The US Chemical Safety Board renewed its call for stronger security at rural oil and gas wellsites as it released a study identifying 26 explosions in the US that have killed 44 members of the public and injured 25 others under the age of 25 since 1983. It issued the recommendation as it released a report on three separate blasts at wells in Mississippi, Oklahoma, and Texas that killed trespassers between October 2009 and April 2010.
Investigators found that the three accidents occurred in isolated, rural wooded areas at production sites that were unfenced, did not have clear or legible warning signs, and did not have hatch locks to prevent access to the flammable hydrocarbons inside the tanks, CSB officials said at an Oct. 27 briefing in Hattiesburg, Miss.
“After reviewing the work of our investigators, I believe that these incidents were entirely preventable,” CSB Chairman Rafael Moure-Eraso said. “Basic security measures and warning signs—as well as more safely designed storage tanks—will essentially prevent kids from being killed in tank explosions at these sites.”
CSB said its investigation found a few major cities and some states, such as California and Ohio, already require varying levels of security for oil and gas production sites, such as fencing, locked or sealed tank hatches, and warning signs. As a result, California did not appear to have any fatal tank explosions between 1983 and 2011, it said.
However, many other large oil and gas producing states have no such requirements, it continued. Two major oil producing states, Texas and Oklahoma, require fencing and warning signs for certain sites that have toxic gas hazards but not for all sites with flammable storage tanks, according to CSB.
Among the report’s six formal safety recommendations, CSB urged that state regulators require the use of flame arrestors, pressure-vacuum vents, floating roofs, vapor recovery systems, and other inherently safe tank design features. The safety measures, which are similar to those already used in refineries and other downstream storage tanks, reduce emissions of flammable vapor from the tanks or otherwise prevent an external flame from igniting vapor inside the tank, it said.
The board also recommended that the US Environmental Protection Agency issue a safety bulletin warning of storage tanks’ explosion hazards; describe the importance of increased security measures such as fencing, gates and signs; and recommend the use of inherently safer storage tank design. Similarly, the recommendations seek to address the current gaps in regulations and codes in Mississippi, Oklahoma, and Texas, CSB said.
CSB’s investigation also examined industry codes and standards, such as those from the American Petroleum Institute and the National Fire Protection Association. It said the final report recommends that both organizations adequately address hazards that upstream oil and gas sites present to the public through amendments to their existing codes or creation of additional guidance.
Specifically, it recommended that API warn of the explosion hazards presented by exploration and production sites, including requirements for security measures such as fencing gates and signs, recommendations for inherently safer storage tank design, and acknowledgment of the public safety issue presented by these sites.
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