Nothing in this chapter shall in any way affect or detract from specific statutory obligations of any government agency to comply with criteria or standards of environmental quality or to perform other statutory obligations imposed upon it, except those specified in Code Section 12-16-6; to coordinate or consult with any other government agency or federal agency; or to act, or refrain from acting, contingent upon the recommendations or certification of any other government agency or federal agency. A government agency shall be deemed to have complied with the requirements of this chapter for a proposed governmental action that requires and has received federal approval of an environmental document prepared in accordance with the National Environmental Policy Act of 1969, as amended, and its implementing regulations.