ST. PETERSBURG — Raytheon wants to zap the toxic plume spreading under the Azalea neighborhood with a combination of hot electrodes and chemical doses designed to neutralize the pollution, according to its latest plan filed this week with state environmental regulators.
Meanwhile the company wants to sink new cleanup wells throughout the area to pump what's left of the pollution out from underground.
The company's latest cleanup plan, made public late Wednesday, is the first one to propose a way to deal with the plume of contamination that has been spreading through the neighborhood. Previous plans concerned only the cleanup of Raytheon's own property near Tyrone Square Mall.
The new plan "describes an aggressive approach using multiple technologies," company spokesman Jon Kasle said. It's designed to rid the neighborhood of contamination "with as little impact to the community as possible."
State Department of Environmental Protection spokeswoman Pam Vazquez said regulators had just received the 2,200-page plan and could not comment until they had completed a full review. The DEP has until October to study the plan and decide whether to approve it. Work could begin as soon as the DEP approves the plan.
Michael Papantonio, an attorney for Azalea residents involved in one of multiple lawsuits filed last year over the pollution, said he had not seen the plan but he was skeptical. Generally, he said, the cleanup plans that corporations like Raytheon propose are "always the minimum, and after they do the minimum, people are still left hanging. All it does is put everyone at ease without solving the problem."
There are 10 contaminants in the toxic underground plume, but the predominant ones are a pair of cancer-causing chemicals called 1,4-dioxane and trichloroethene. Raytheon has already begun using something called "pump-and-treat" to clean up the pollution beneath its own property. That involves sinking wells into the groundwater that's contaminated and pumping it into holding tanks to be cleaned. Raytheon's new plan calls for expanding the pump-and-treat process to 11 new wells scattered around the Azalea neighborhood. But the process is slow.
So the plan also proposes zapping the source of the contamination with "thermal treatment" and "chemical oxidation" to neutralize the toxics. Thermal treatment involves sticking electrodes into wells sunk into the highest concentration of the pollution, then heating the electrodes to vaporize it. The vapors are then sucked out and treated.
The chemical oxidation process, on the other hand, reacts with the pollutants to "destroy them on contact," Kasle said, leaving behind only clean water, carbon dioxide and trace amounts of salt.
Workers discovered the contamination in 1991 during construction of the Pinellas Trail, which runs next to the Raytheon property. The pollution originated from a drum storage area on the site, which had belonged to a company called E-Systems.
The factory, built in the 1950s, has long been used for manufacturing electronic components that produced a variety of toxic chemicals.
When Raytheon bought E-Systems in 1995, it inherited the pollution headache but did little beyond monitoring the problem. Raytheon and DEP officials knew in 1999 that the pollution had begun spreading beyond Raytheon's property, but failed to notify area residents until last year. By then the toxic waste dumped at the site had spread throughout the Azalea neighborhood, contaminating 19 irrigation wells out of 352 checked by Raytheon's contractor.
The state Department of Health and a University of Florida expert working for the DEP have found no health risks from the contamination.