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A Solution for Mobile Smelting

DTSC “cap and contain” remedy protects residents, environment from toxic inheritance left by recycler
 

Environmental activists call the 11-acre patch of Kern County’s Mojave Desert the largest-known stockpile of deadly dioxin in America. In the 1980s and 1990s, the now-abandoned site near Mojave and Rosamond ranked among California’s most notorious generators of hazardous waste.

Now, DTSC plans a $3.5-million cleanup financed by legal settlements at Mobile Smelting. The small recycling operator left an enduring toxic inheritance for neighbors and activists as it burned tons of scrap airplane parts, copper wiring and transformer coils in furnaces from 1970 to 1990. “Mobile Smelting has been a very long-running issue for us with the dioxin there,” said Jane Williams, director of a local environmental group, Desert Citizens Against Pollution (DCAP). “We take a keen interest in it.”

In May DTSC plans to take public comment from DCAP and others on its draft Removal Action Plan to bury and cap tons of dioxin-contaminated ash produced at the 11-acre smelting site.

“That’s the root of the problem,” said Jeff Gymer, a DTSC hazardous substances engineer and project manager for the Mobile Smelting cleanup. “If we remediate the site the contamination won’t spread. That will prevent additional dispersion.”

Presently, contaminated ash is stored at the abandoned site in a pair of cargo containers and 88 55-gallon drums. Before the state negotiated a 1990 agreement with the owner to close the operation, desert winds blew the toxic ash across 1,700 neighboring acres and a scattering of homes, coating the landscape with dangerous levels of dioxin.

The World Health Organization defines dioxins as a group of highly toxic chemical-related compounds that “can cause reproductive and developmental problems, damage the immune system, interfere with hormones, and also cause cancer.”

Nearby surface soil samples showed dioxin levels of 49,266 parts per trillion. By comparison, the standard cleanup goal for dioxin in soil at industrial properties is 1,000 parts per trillion – 50 times lower.

DTSC proposes to bury the toxic ash in an excavated area approximately15 feet deep and 360 feet by 320 feet in dimension. The department would cover the dioxin-contaminated material with one foot of clean soil, cap it with an impermeable clay mat, and add two more feet of fresh soil above the cap.

DTSC, which frequently uses such proven “cap and contain” solutions to reduce exposure to dangerous substances, calls it an “effective and reliable alternative.” The solution is combined with land use restrictions that prevent future incompatible uses on the site such as houses.

More work remains. On a neighboring 156 acres, Courtauld Aerospace Group plans a separate cleanup and burial of 3,500 cubic yards of soil contaminated with lead and dioxins. Isolated areas of dioxin contamination remain in areas where wind carried the contaminant. DTSC’s Gymer said the department will remove remaining “hot spots” when funding is available.

 
DTSC “cap and contain” remedy 
protects residents, environment from toxic inheritance left by recycler
 
 
 
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