Joseph Aggio owned a 156-acre parcel of land in Cotati, Calif., which was leased to the Cotati Rod and Gun Club. The club used the land for firing and shooting ranges from 1958 to 1998. From 1981 to 1985, Sequoia Insurance Co. provided liability insurance for Aggio on the property. In 1988, Aggio died, leaving the property to his three children.
At some point in time, it was discovered that the gun club's operations had contaminated the land with lead. In 1995, the gun club agreed to investigate and decontaminate the property, under a voluntary agreement with the State of California and its Department of Toxic Substances Control, as well as the federal Environmental Protection Agency. In 2005, Aggio's children spent more than $1 million to carry out the lead