Casmalia is an unincorporated town in Santa Barbara County, California located just outside the borders of Vandenberg Air Force Base about 5 miles (8.0 km) southwest of Santa Maria. Approximately 200 people live in and near Casmalia. The ZIP Code is 93429, and the community is inside area code 805.
The town was the site of a hazardous waste landfill that began operating in 1973 and accepted toxic chemicals like PCBs, motor oil, and pesticides. In 1989, the facility was closed down following a number of permit violations. In 1992, it was taken over by the federal Environmental Protection Agency, which began the process of cleaning up and administering the site.The soil and groundwater at the site were found to be significantly contaminated and the former dump became a Superfund site. During its operation, 4.5 billion pounds of hazardous waste from up to 10,000 individuals, businesses and government agencies were buried at the site.