An older design for the U.S. Navy Environmental Protection Award flag, which is awarded for various environmental  achievements.  The award is apparently detailed in SECNAVINST 5090.5F, part of the Navy's Environmental Programs Manual.  The central design is the ecology symbol; this was replaced in the mid-1990s with a symbol containing stylized trees, waves, and a bird inside a circle.  For more information, see here, here, and U.S. Navy document NTP 13(B) [1] section 1606.
Own work
Carl Lindberg