From 1963 to 1985, aerospace manufacturing company Senior Aerospace Ketema (formerly Ametek) in El Cajon dumped thousands of pounds of a chemical degreaser into a shallow redwood-lined pit that sat on its property.
This resulted in a toxic groundwater plume of trichloroethylene, which travels through the soil by a process called soil vapor intrusion into the three large mobile home parks surrounding the facility — Greenfield, Starlight and Villa Cajon — as well as Magnolia Elementary School.
This caused related illnesses among residents and students alike. The air in one mobile home at the school had more than twice the amount that triggered an immediate closure of Magnolia Elementary in the 2015-16 school year due to health concerns. TCE is known to cause a variety of cancers, cause reproductive harm, damage the immune system, and can cause dizziness, headaches, and confusion.