LA MESA, Calif. --
Sabotage by an insider at a major utility facility -- including a chemical or oil refinery -- could provide al-Qaida with its best opportunity for the kind of massive Sept. 11 anniversary attack Osama bin Laden was planning, according to a new report by U.S. officials.
The Department of Homeland Security issued a warning on Wednesday that "violent extremists have obtained insider positions," and that "outsiders have attempted to solicit utility-sector employees" for damaging physical and cyber attacks at U.S. utilities.
According to the DHS, "Based on the reliable reporting of previous incidents, we have high confidence in our judgment that insiders and their actions pose a significant threat to the infrastructure and information systems of U.S. facilities."
There are more than 20 secure utility facilities in San Diego and Imperial Counties that report having one or more hazardous chemicals on site.
"It's a very serious warning," security consultant Glen Wynn said. "You always have that potential for a mole who has been in place for a number of years and can cause that mayhem in a moment."
The DHS warning does not name specific targets or places that have been compromised.
In November 2009, the 10News I-Team reported on two secure water treatment plants in San Diego County, the Escondido treatment plant and Alvarado Water Treatment plant in La Mesa. Both use chlorine gas to purify water.
"When chlorine is used as a gas, there's the danger of an emergency release forming a dense, ground-hugging plume and drifting off site for many miles and being very harmful to people," said chemical safety advocate Paul Orum.
Since 2009, the La Mesa plant has switched purification products and now primarily uses non-hazardous materials to treat the water.
The Escondido plant did not say if chlorine was still being used.
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