"Major action" means an action that is likely to have significant adverse environmental impacts. "Major" reinforces but does not have a meaning independent of "significantly" (WAC 197-11-794).
Wash. Admin. Code § 197-11-764
Statutory Authority: RCW 43.21C.110. 84-05-020 (Order DE 83-39), § 197-11-764, filed 2/10/84, effective 4/4/84.