(Joint Base Lewis-McChord, WA)  --  The civilian workforce at Washington's Joint Base Lewis-McChord is about to shrink.  Officials say it will be the first major reduction in the number of civilian employees at the base since the Army began post-Iraq downsizing.  The schedule calls for 900 full-time and contractor positions to be shed over the next two years.  The Tacoma "News Tribune" reports the base currently employs nearly 16-thousand-400 civilians.