Keith Grueneberg, chairman of the Nevada County Consolidated Fire District Board of Directors, has resigned as the district’s chair for personal reasons effective immediately, according to a Friday news release. Grueneberg has been at the center of a swirl of controversy since ascending to the position of chair in 2013. Recently, Grueneberg caught some heat for circulating a potentially offensive email with the subject line of “Hooked on Ebonics?” Fellow director, David Hanson, labeled the circulation of the mail to employees using public email addresses “very inappropriate.” Grueneberg said the video was a parody and meant to emphasize communication problems …