California Code
ARTICLE 2 - Definitions
Section 25395.77.

25395.77. “Passive migration” means the leaking, leaching or movement of a hazardous material into or through the environment, for which no human activity by the bona fide purchaser, innocent landowner, or contiguous property owner preceded the initial entry of that substance into the environment.

(Added by Stats. 2004, Ch. 705, Sec. 1. Effective January 1, 2005. Repealed as of January 1, 2027, pursuant to Section 25395.109, with continuing effect as provided in Section 25395.110.)