Attempting to reform a “broken” tax assessment system costing taxpayers $250 million yearly, Nassau County Executive Edward Mangano appointed former Smithtown Assessor Gregory Hild to chair a transition team Monday.

Mangano fired County Assessor Ted Jankowski last week.

Hild will lead the search for a new county assessor and other improvements. Property tax assessment reform remains a controversial issue in Nassau County with school officials opposing Mangano’s proposed tax assessment shift to the districts.