A longtime planning commissioner for the city of Simi Valley will not seek another term after a dozen years on the board. Rick Kunz said he would step down from the position after the end of the term, the city announced. He has been appointed to the board all 12 years Mayor Paul Miller has been in office. Miller plans to nominate Simi Valley resident and local business owner Keith Mashburn to fill the position. The appointment awaits City Council approval.