The chairman of the Mahaska County Board was arrested Sunday (2/7) on a charge of domestic abuse.  The Mahaska County Sheriff’s Office says 53-year-old Mark Groenendyk is charged with first degree domestic abuse assault.  According to court records, Oskaloosa Police were called to Mahaska Health Saturday night (2/6) about an assault.  One of Groenendyk’s sons told Police that he was working in the shop with his father when Groenendyk suddenly became angry with him and slammed him into a corner, punched him once in the chest and slammed his head against the wall several times.  Groenendyk has a preliminary hearing February 17.  A criminal charge is merely an accusation, and the defendant is presumed innocent until and unless proven guilty.